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General Category => Yeast and Fermentation => Topic started by: ultravista on October 04, 2014, 08:18:46 PM

Title: HELP: WLP540 Abbey IV Attenuation
Post by: ultravista on October 04, 2014, 08:18:46 PM
On 09/05, I brewed a Rochefort 8 - mashed at 149F, with an OG 1.087, aerated with O2, pitched with a 3L starter of WLP540 Abbey IV, and fermented at 71-72F. Beersmith estimated this to land somewhere near 1.010.

Exactly a month later, it is at 1.023 despite rousing the yeast, bumping to 74F, and adding leftover yeast from the 3L starter.

Beersmith calculates 1.087 > 1.023 as 71.9% apparent attenuation. White labs states 74-82% attenuation.

At this point, it is a bit too sweet, and I don't know what else to do to bring it down.

Should I perhaps bring it up a few more degrees and rouse the yeast again? If yes, how high should I go at this point? Ambient house temperature is approximately 78 F.

Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: HoosierBrew on October 04, 2014, 09:30:32 PM

Should I perhaps bring it up a few more degrees and rouse the yeast again?



Yeah, I would. No major worries with the temp now  - the first several days would've determined the flavor profile. Give it a gentle rouse and warm up near 80F for several more days. I hope it helps. Let us know !


EDIT  -  Also, did you use a hydrometer or refractometer to measure FG ?  Using a refractometer for FG requires a correction to account for the alcohol present. Just wondering, in case you got a bad reading.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: ultravista on October 05, 2014, 03:52:03 PM
I use a Thermapen thermometer for the mash and testing with two hydrometers. Both read exactly the same.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: brewinhard on October 05, 2014, 06:38:05 PM
Did you provide the wort with proper aeration when pitching your yeast?  Was your grain bill heavy on specialty malts that might reduce attenuation?
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: ultravista on October 05, 2014, 09:42:11 PM
Aerated with 02 for about a minute. Specialty malts were low, primarily 2-row. I did use 2 # of Candi Syrup's D180 at the end of the boil.

I have since re-roused the yeast and moved the thermostat to 78F.

I would be ecstatic if it dropped another 10 points.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: HoosierBrew on October 05, 2014, 09:44:58 PM
Aerated with 02 for about a minute. Specialty malts were low, primarily 2-row. I did use 2 # of Candi Syrup's D180 at the end of the boil.

I have since re-roused the yeast and moved the thermostat to 78F.

I would be ecstatic if it dropped another 10 points.

Given your recipe and process I would think it'll drop some more points. I'll be curious to see how you come out. Good luck !
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: egg on October 15, 2014, 05:24:58 PM
How's this going?

I have a Holtrop-ish Rochefort 8 on the go too, 21 liters OG 1.079, with the WLP 540 (700ml stepped to 3.5L starter) which is at 1.016 after 2.5 weeks, sat at 76F (pitched at 63) having been roused several times.  It looks to be going no lower, so about 80%AA.  My adaptations led to 15% sugar in total and the mash was 2.5hrs at 147, with a brief mash out to follow.

Going by Stan Hieronymous' figures for OG and attenuation, it looks like the real thing finishes around 1.008/9.  I wish I could get it down there.  Tastes great, but a 1.016 body with 3.5vols plus of CO2 will be a pretty full mouth feel.  I guess I've just got to mash even lower next time.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: morticaixavier on October 15, 2014, 05:28:23 PM
How's this going?

I have a Holtrop-ish Rochefort 8 on the go too, 21 liters OG 1.079, with the WLP 540 (700ml stepped to 3.5L starter) which is at 1.016 after 2.5 weeks, sat at 76F (pitched at 63) having been roused several times.  It looks to be going no lower, so about 80%AA.  My adaptations led to 15% sugar in total and the mash was 2.5hrs at 147, with a brief mash out to follow.

Going by Stan Hieronymous' figures for OG and attenuation, it looks like the real thing finishes around 1.008/9.  I wish I could get it down there.  Tastes great, but a 1.016 body with 3.5vols plus of CO2 will be a pretty full mouth feel.  I guess I've just got to mash even lower next time.

with 15% sugar and a 147 mash temp you should be able to get 1.079 down to 1.008 without a problem.

starter size sounds sufficient too. If you mash too much lower you'll drop out the bottom of the alpha range and won't get as fermentable a wort because the alpha amylase won't be breaking the longer chain sugars to allow the beta amylase to nip off the ends.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: HoosierBrew on October 15, 2014, 05:48:30 PM
How's this going?

I have a Holtrop-ish Rochefort 8 on the go too, 21 liters OG 1.079, with the WLP 540 (700ml stepped to 3.5L starter) which is at 1.016 after 2.5 weeks, sat at 76F (pitched at 63) having been roused several times.  It looks to be going no lower, so about 80%AA.  My adaptations led to 15% sugar in total and the mash was 2.5hrs at 147, with a brief mash out to follow.

Going by Stan Hieronymous' figures for OG and attenuation, it looks like the real thing finishes around 1.008/9.  I wish I could get it down there.  Tastes great, but a 1.016 body with 3.5vols plus of CO2 will be a pretty full mouth feel.  I guess I've just got to mash even lower next time.

+1 to Jonathan's comments. I wouldn't mash lower than that. Are you measuring your FG by hydrometer or refractometer? If hydrometer, is it reading accurately ? If refractometer, did you do a correction for the abv present ? I agree that if you roused and it's been @ 76F that it's probably done.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: S. cerevisiae on October 15, 2014, 06:24:05 PM
Beersmith calculates 1.087 > 1.023 as 71.9% apparent attenuation. White labs states 74-82% attenuation.

If Beersmith is telling you that 1.087 to 1.023 is 71.9% apparent attenuation, then there is a bug in Brad's software. 

AA = (O.G. - F.G.) / (O.G. - 1) x 100 (multiplying by 100 yields AA as a percentage value instead of as a fraction)

AA = (1.087 - 1.023) / (1.087 - 1) x 100 = 73.6%  (which is the lower end of the given range for the strain)

Here's a clear cut example of why it is important for all brewers to learn basic brewing mathematics before using brewing software.

Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: narvin on October 15, 2014, 06:31:44 PM
In limited experience, I've also seen "underattenuation" (at least in terms of what Rochefort gets) with the first generation of this yeast.  Doing a 6 -> 8 -> 10 clone series repitching from one to the next resulted in much better attenuation.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: S. cerevisiae on October 15, 2014, 06:57:41 PM
Was it a single-step or a two-step starter? What was your starter gravity? 

A lot of brewers make the mistake of brewing a big beer with yeast grown in 1.040 gravity wort.  Pitching a culture grown in 1.040 wort into 1.087 wort seriously stresses the yeast cells.   A better approach is to pitch the vial into 1L of 1.030 gravity wort, wait twelve to eighteen hours, chill and decant the supernatant (a.k.a the clear liquid that lies above the slurry), and then pitch the slurry into 3 liters of 1.060 wort.  Using this process, we are also increasing osmotic pressure with each step.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: egg on October 15, 2014, 08:30:38 PM
In limited experience, I've also seen "underattenuation" (at least in terms of what Rochefort gets) with the first generation of this yeast.  Doing a 6 -> 8 -> 10 clone series repitching from one to the next resulted in much better attenuation.

This makes sense.  With WLP 530, I've had tripels drop as far as 1.085 to 1.009 with 13% sugar (I've never harvested and repitched yet) and a 150F mash.  Looking around, 540 seems like a very different animal.

Not sure if it's a consideration for the OP too, but I'm considering krausening-in some US-05.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: narvin on October 16, 2014, 01:26:30 AM

A lot of brewers make the mistake of brewing a big beer with yeast grown in 1.040 gravity wort.  Pitching a culture grown in 1.040 wort into 1.087 wort seriously stresses the yeast cells.   A better approach is to pitch the vial into 1L of 1.030 gravity wort, wait twelve to eighteen hours, chill and decant the supernatant (a.k.a the clear liquid that lies above the slurry), and then pitch the slurry into 3 liters of 1.060 wort.  Using this process, we are also increasing osmotic pressure with each step.

There are no hard and fast rules, but I would say that in most cases the mistake is making a high gravity starter.

The starter was well within the ratio of growth (4X at most). The gravity was low, the way every yeast lab propagates yeast.  The idea is that you can pitch the correct number of cells, grown in ideal conditions (LOW GRAVITY WORT).

Whether or not this is always true is another deal.  540 is one of the few where I've had any problem at all with starter grown yeast.  However, I would never encourage someone to make high gravity starters.  But obviously certain yeasts benefit more than others from growing in brewing conditions.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: ynotbrusum on October 16, 2014, 02:38:11 AM
I always wait to pitch my candy sugar until at least high krausen for this reason.  Not based on science at all, just based on general observation....don't give the yeast the dessert until they pretty much are finished with dinner.  I may have just been a lucky SOB, but I get almost all Belgians to finish well into the upper range attenuation stated for the yeast.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: Joe Sr. on October 16, 2014, 02:53:44 AM
1.087 is not that big, in my estimation.  There is no reason this shouldn't attenuate further.

I'd go with a decent sized starter pitched when the yeast is active.

Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: ultravista on October 16, 2014, 04:15:37 AM
Beersmith calculates 1.087 > 1.023 as 71.9% apparent attenuation. White labs states 74-82% attenuation.

If Beersmith is telling you that 1.087 to 1.023 is 71.9% apparent attenuation, then there is a bug in Brad's software. 

AA = (O.G. - F.G.) / (O.G. - 1) x 100 (multiplying by 100 yields AA as a percentage value instead of as a fraction)

AA = (1.087 - 1.023) / (1.087 - 1) x 100 = 73.6%  (which is the lower end of the given range for the strain)

Here's a clear cut example of why it is important for all brewers to learn basic brewing mathematics before using brewing software.

(http://www.ultravista.com/pics/temp/BS-Gravity.jpg)

From the Alcohol and Attenuation Tool in BS 2.1.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: erockrph on October 16, 2014, 06:38:50 AM
Was it a single-step or a two-step starter? What was your starter gravity? 

A lot of brewers make the mistake of brewing a big beer with yeast grown in 1.040 gravity wort.  Pitching a culture grown in 1.040 wort into 1.087 wort seriously stresses the yeast cells.   A better approach is to pitch the vial into 1L of 1.030 gravity wort, wait twelve to eighteen hours, chill and decant the supernatant (a.k.a the clear liquid that lies above the slurry), and then pitch the slurry into 3 liters of 1.060 wort.  Using this process, we are also increasing osmotic pressure with each step.
I'm not disagreeing, as my own experience with pitching slurries from 1.060ish beers has been quite successful, but I am curious what the biology is behind this. Is there a mechanism that the yeast has to acclimate to higher osmotic pressures?

There are no hard and fast rules, but I would say that in most cases the mistake is making a high gravity starter.

The starter was well within the ratio of growth (4X at most). The gravity was low, the way every yeast lab propagates yeast.  The idea is that you can pitch the correct number of cells, grown in ideal conditions (LOW GRAVITY WORT).

Whether or not this is always true is another deal.  540 is one of the few where I've had any problem at all with starter grown yeast.  However, I would never encourage someone to make high gravity starters.  But obviously certain yeasts benefit more than others from growing in brewing conditions.

I think the key here is the recommendation to pitch at 12-18 hours, and not after the starter has fermented to completion. I think the alcohol content in the starter is probably the biggest detriment to yeast health. By pitching earlier in the process you will avoid some of that alcohol.

Kai ran an experiment a few years ago comparing yeast growth (per gram of extract) vs starter gravity. He saw virtually no difference between a 5,7 or 10 Plato starter wort on yeast growth, and they were all at nearly 100% viability. A 20 Plato wort did see a 33% lower growth rate and was about 90% viable. He attributed the lower viability to the alcohol content. It's unclear where the break point is between 10 and 20 Plato where yeast growth and viability start to tail off in a starter, but even at 20 Plato the results weren't disastrous. It stands to reason that a 1.060 starter isn't going to be horrendously detrimental to yeast health.

http://braukaiser.com/blog/blog/2013/05/28/starter-wort-gravity-and-yeast-growth/
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: egg on October 16, 2014, 12:16:20 PM
1.087 is not that big, in my estimation.  There is no reason this shouldn't attenuate further.

I'd go with a decent sized starter pitched when the yeast is active.

Is this advice to try to get the FG down a bit? I'm going to do the same later today with my own, 'stuck' at 1.016.  Guessing I will have to stick to a 1L starter (using US-05) to keep to the general rule of keeping it below 5% of the 21L batch, seeing it won't be decanted.  Not sure whether to use 1 sachet or two, though will assume I should stick to 1.040 wort.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: HoosierBrew on October 16, 2014, 12:44:03 PM
I must have been lucky with 540/WY1762. It's my go to strain for dubbel and quad and I've used it many times, finishing 1.010ish (occasionally below) on first pitch. But I mash low, usually 149F for dubbel and 148F for quad, 15%+ sugar/syrup, plenty of yeast, nutrient, and oxygenation.


EDIT  -  I will add though that I've only used WY1762, never WLP540. So I don't know if there are any subtle differences in performance associated there.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: Joe Sr. on October 16, 2014, 01:43:12 PM
1.087 is not that big, in my estimation.  There is no reason this shouldn't attenuate further.

I'd go with a decent sized starter pitched when the yeast is active.

Is this advice to try to get the FG down a bit? I'm going to do the same later today with my own, 'stuck' at 1.016.  Guessing I will have to stick to a 1L starter (using US-05) to keep to the general rule of keeping it below 5% of the 21L batch, seeing it won't be decanted.  Not sure whether to use 1 sachet or two, though will assume I should stick to 1.040 wort.

Yes.  I haven't had great luck with it, but others have reported that pitching fresh active yeast has been effective at finishing out bigger beers that have stalled.  I've found that patience is required.

I think you want a LOT of yeast for this, so a bigger starter wouldn't hurt.  Or slurry from another batch.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: ultravista on October 16, 2014, 01:59:06 PM
Here is a response from White Labs regarding autolysis and reducing the gravity.

-------------------------------------
Autolysis will happen as soon as there are dead yeast cells that begin to decay. It is recommended to remove old yeast as early and often as possible to avoid autolysis off flavors, but it can be a desirable flavor characteristic in some products.

For instance Champagne is almost entirely distinguished by autolysis flavors and this is intentional. They age it a minimum of 18 months to incorporate this characteristic. It may be desirable in certain aged beers as well.

As far as reducing the gravity, you are left with very few options. You can rouse the yeast and warm it up, or you can try pitching a new volume of highly active yeast. You want the yeast to be highly active so that it can endure the stresses of starting in a hostile environment. More yeast will only help if you have the available sugars for fermentation. It is likely that the addition of yeast will perform for a breif while and then cease action again. Hopefully this is enough to get you to the target final gravity. If not, you may have to repeat this process.

It is possible that the yeast have consumed all the available sugars and that the remaining sugars are too complex for the yeast to break down. This would be evident if adding more yeast did not effect the final gravity. In this case you would be limited to back blending the beer into a new wort and continuing fermentation as a new batch.

Early stalling is usually attributed to poor cell growth during fermentation. It can be influenced by things such as over pitching, low aeration, or nutrient deficiencies, among other things.
-------------------------------------
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: denny on October 16, 2014, 03:19:35 PM
How's this going?

I have a Holtrop-ish Rochefort 8 on the go too, 21 liters OG 1.079, with the WLP 540 (700ml stepped to 3.5L starter) which is at 1.016 after 2.5 weeks, sat at 76F (pitched at 63) having been roused several times.  It looks to be going no lower, so about 80%AA.  My adaptations led to 15% sugar in total and the mash was 2.5hrs at 147, with a brief mash out to follow.

Going by Stan Hieronymous' figures for OG and attenuation, it looks like the real thing finishes around 1.008/9.  I wish I could get it down there.  Tastes great, but a 1.016 body with 3.5vols plus of CO2 will be a pretty full mouth feel.  I guess I've just got to mash even lower next time.

Stan also says that the last 10% of attenuation can take as long as the first 90%.  At only 2.5 weeks you may be prematurely concerned.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: egg on October 16, 2014, 04:02:48 PM
How's this going?

I have a Holtrop-ish Rochefort 8 on the go too, 21 liters OG 1.079, with the WLP 540 (700ml stepped to 3.5L starter) which is at 1.016 after 2.5 weeks, sat at 76F (pitched at 63) having been roused several times.  It looks to be going no lower, so about 80%AA.  My adaptations led to 15% sugar in total and the mash was 2.5hrs at 147, with a brief mash out to follow.

Going by Stan Hieronymous' figures for OG and attenuation, it looks like the real thing finishes around 1.008/9.  I wish I could get it down there.  Tastes great, but a 1.016 body with 3.5vols plus of CO2 will be a pretty full mouth feel.  I guess I've just got to mash even lower next time.

Stan also says that the last 10% of attenuation can take as long as the first 90%.  At only 2.5 weeks you may be prematurely concerned.

I appreciate your thoughts. Not to be confused with the OP here, but as far as mine is concerned, it's not going anywhere. I am certainly here to learn, though I'm used to the 10%/90% thing with wlp 530. I have a single point finishing hydrometer and enough fermentations under my belt to say that with some confidence.  If there was any movement at all, I would leave it.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: brewinhard on October 16, 2014, 10:55:13 PM
1.087 is not that big, in my estimation.  There is no reason this shouldn't attenuate further.

I'd go with a decent sized starter pitched when the yeast is active.

Is this advice to try to get the FG down a bit? I'm going to do the same later today with my own, 'stuck' at 1.016.  Guessing I will have to stick to a 1L starter (using US-05) to keep to the general rule of keeping it below 5% of the 21L batch, seeing it won't be decanted.  Not sure whether to use 1 sachet or two, though will assume I should stick to 1.040 wort.

I don't see a 1.016 FG as a high FG for a Belgian Quad.  With some decent carbonation the beer will taste just fine.  I have made Quads that finish in the low 1.020's that were amazing and placed in several comps in the past. I find that sometimes when these styles dry out too much they lack a bit of character and sweetness that is noticeable in commercial versions.  Just my 2 cents which doesn't go for much nowadays.... ;)
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: S. cerevisiae on October 17, 2014, 02:24:05 AM
The reason why we want to avoid dumping yeast cells from a White Labs vial into 1.060 wort is because we are dealing with a unknown number of viable cells that may not be in the best of health.  A large deferential between the amount of solute inside of the cell and the amount of solute outside of the cell will cause water to migrate through the cell membrane to outside of the cell, resulting in dehydration,  which, in turn, can result in cytorrhysis (the complete collapse of the cell wall).  It also helps that it is easier to dissolve oxygen in 1.030 wort than it is 1.060 wort.

Do you why pitch rate increases with respect to gravity?  It’s because the osmotic pressures encountered in high gravity wort place a lot of stress on a yeast cell’s plasma membrane (i.e., the high solute differential thing mentioned above).  If we couple the osmotic pressure problem with the fact that it is more difficult to dissolve oxygen in high gravity wort than it is low gravity wort, we quickly realize that we have to limit the number cell divisions that need to occur before the stationary phase is reached, as each division results in a mother cell sharing its ergosterol and unsaturated fatty acid (UFA) reserves with its daughter cell (replacement divisions will need to occur during the stationary phase; hence, we need reserves going into the stationary phase).  Ergosterol and UFAs are critical cell plasma membrane health because they make it more pliable, which, in turn, is critical yeast cell metabolism.

An important thing to remember is that a yeast cell loses turgor pressure when it shrinks due hypertonic situations (high levels of external solutes).  Turgor pressure is the pressure that pushes a yeast cell’s plasma membrane against its cell wall. 

Another problem that we encounter in high gravity fermentation are high ethanol levels. Ethanol is hygroscopic, which results in water being drawn out of the cells through their plasma membranes, which, in turn, results in shrinkage and loss of turgor pressure.  In effect, yeast cells quit fermenting at a point because they become too dehydrated to pass nutrients and waste products through their plasma membranes, eventually resulting in cell death.

With that said, we encounter two problems when growing yeast cells for use in high gravity fermentations.  The first problem is basic biomass growth, that is, we need to increase the overall yeast cell count, so that our pitch rate is closer to maximum cell density.  The second problem is that we need to grow cells that do not go into the yeast equivalent of cardiac arrest when pitched into high gravity wort.   What we are doing by increasing the gravity with each step is progressively selecting cells that can endure higher and higher osmotic pressures.  It’s basically survival of the fittest. The cells that do not have the right stuff do not replicate and are replaced by the offspring of cells that do have the right stuff.  This selection process is basically what happens in the 6 -> 8 -> 10 progression that narvin mentioned.  There is nothing magical about using a larger batch. It’s all fermentative growth.

Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: narvin on October 17, 2014, 01:20:58 PM
That makes sense.

So, have you done a 2 step starter with a higher gravity wort for the second step?  I might try that next time I want to go straight to a very high gravity batch(1.090+).  Of course, there's a certain point where it's just as easy to make a lower gravity batch of beer as your "starter".
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: S. cerevisiae on October 17, 2014, 01:50:51 PM
Beersmith calculates 1.087 > 1.023 as 71.9% apparent attenuation. White labs states 74-82% attenuation.

If Beersmith is telling you that 1.087 to 1.023 is 71.9% apparent attenuation, then there is a bug in Brad's software. 

AA = (O.G. - F.G.) / (O.G. - 1) x 100 (multiplying by 100 yields AA as a percentage value instead of as a fraction)

AA = (1.087 - 1.023) / (1.087 - 1) x 100 = 73.6%  (which is the lower end of the given range for the strain)

Here's a clear cut example of why it is important for all brewers to learn basic brewing mathematics before using brewing software.

(http://www.ultravista.com/pics/temp/BS-Gravity.jpg)

From the Alcohol and Attenuation Tool in BS 2.1.

Either Brad Smith knows something that the rest of the brewing world does not, or he needs to perform more thorough code reviews.  My bet is that there is a bug in Brad's software because here is a posting that he made on his site (http://www.beersmith.com/forum/index.php/topic,1928.msg7731.html?PHPSESSID=3ca218961138cfb86bbf62f439f229de#msg7731):

"  The apparent attenuation numbers can be calculated by hand as follows:
    apparent attenuation = ( ( OG in points - FG in points ) / OG in points ) x 100
"


To convert a specific gravity reading to points, we merely lop off the 1 and treat the number on the right-hand side of the decimal point as a whole number, which is equivalent to performing the following operation:  (S.G. - 1.0) x 1000


Example:

1.087 in gravity points = (1.087 - 1.0) x 1000 = 87
1.023 in gravity points = (1.023 - 1.0) x 1000 = 23

(87 - 23) / 87 x 100 = 73.6%


Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: ultravista on October 17, 2014, 02:09:59 PM
S. cerevisiae - thank you for your feedback. I rely on Beersmith and rarely run calculations elsewhere. Moving forward, I will check via Excel.

Gravity was down to 1.021 last Saturday and I decided to begin chilling. This week will be 6 weeks since pitching. I believe that it may be down another point or two by tomorrow. Around 77% attenuation.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: Joe Sr. on October 17, 2014, 02:16:38 PM
If you start chilling you likely won't go any lower.  If you're happy with 1.021 that's fine, but if you think it should be lower I would just wait.

I've left big beers for two months to reach terminal gravity.   Sometimes you just have to be patient.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: ultravista on October 17, 2014, 02:19:08 PM
If you start chilling you likely won't go any lower.  If you're happy with 1.021 that's fine, but if you think it should be lower I would just wait.

I've left big beers for two months to reach terminal gravity.   Sometimes you just have to be patient.

I haven't left beer on the yeast cake for longer than 6 weeks. It's about 45 degrees now, perhaps too cold for the yeast to continue nibbling.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: S. cerevisiae on October 17, 2014, 02:20:47 PM
That makes sense.

So, have you done a 2 step starter with a higher gravity wort for the second step?  I might try that next time I want to go straight to a very high gravity batch(1.090+).  Of course, there's a certain point where it's just as easy to make a lower gravity batch of beer as your "starter".

Yes, I have stepped starters in gravity many times.  I have also performed three step 1.020 -> 1.040 -> 1.060 starters when culturing yeast straight from a bottle of Chimay.  I recently taught a very talented young brewer the process.  He too was a doubting Thomas until he tried it on a RIS.   He said that it went against everything that he had read on Internet forums.

If you think about it, there's nothing magical about the process.  The first level starter does all of the heavy lifting when it comes to resuscitating  the culture and getting the cell count up.  It takes at most two replication periods to reach maximum cell density when the slurry from the 1L starter is pitched into the 3L starter. 

I have found that one does not even need a stir plate for this process.  I used to use 5L and 10L media bottles before I took a hiatus from the hobby (they look like large versions of the orange-capped media bottle shown in one of my other posts).  The beauty of using a media bottle is that it can be capped after pitching and shaken until the media is almost all foam.   I still shake the 40ml starters that I inoculate from slant.  I  sold my 5L and 10L media bottles while on hiatus from the hobby.  I have been thinking about ditching my stir plate for a shaker.  Large media bottles are expensive enough that I can justify purchasing a used shaker and a couple of used shaker flasks (they look like Erlenmeyer flasks with baffles on the bottom).  I am a little like James Bond in that I prefer my cultures shaken, not stirred. :)

Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: narvin on October 17, 2014, 02:30:17 PM
I also start cultures from a bottle at 1.20 or so, with other starters being 1.035-1.040.  I generally don't have attenuation problems, especially using WLP530, but 540 was one in the past I've noticed this issue with.  It produces attenuation in the mid 70s, as advertised, but not the 88% that Rochefort gets.  If I'm going to do steps, most of the time I'd rather reuse the yeast from a batch of beer and get two beers.

Re: Beersmith,  he's using degrees Plato for the apparent attenuation numbers.  It seems like ProMash does this as well.  Plato and specific gravity are similar, and measure similar things, but they aren't linear and start to differ more at higher gravities.  Degrees plato is extract percentage by weight, and specific gravity is a measure of density.  I'm not really sure which one is more appropriate, though.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: Joe Sr. on October 17, 2014, 02:54:39 PM
I also start cultures from a bottle at 1.20 or so

This is exactly what I was thinking.  If I'm culturing from a bottle, I start low and step the gravity up with each successive step.  Same methodology as S. is talking about, and it works quite well.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: narcout on October 17, 2014, 04:48:06 PM
He said that it went against everything that he had read on Internet forums.

That surprises me.  It's not that foreign of a concept.  Isn't it also covered in Yeast?

I have been thinking about ditching my stir plate for a shaker.

Is there a particular advantage to one over the other? 
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: S. cerevisiae on October 17, 2014, 06:07:36 PM
Is there a particular advantage to one over the other?

Most amateur brewers are under the false belief that a stir plate spun at slow to medium speed increases yeast cell count, which could not be further from the truth.  A culture that is shaken until the media is almost all foam immediately after pitching has more initial dissolved oxygen than a starter that is merely pitched and placed on a stir plate at a low to medium speed.  A stirred culture has to be stirred at a fast enough speed to create a vortex down to the stir bar in order to provide adequate aeration.  CO2 is denser than air, so there is very little in the way gas exchange in a flask after significant CO2 production has started.   

I am also not convinced that spinning a stir bar at a high rate of speed does not beat the cells up because every starter that I have made on a stir plate has had the telltale smells and tastes associated with yeast stress.  I have never had a shaken starter that I could not pitch without decanting the supernatant.
 
The major advantage that a stir plate offers over merely shaking a culture until it is almost all foam immediately after pitching is that it keeps flocculent yeast strains from prematurely flocculating. However, that advantage is almost insignificant when creating a starter because the goal is to produce yeast cells, not fully attenuate the wort; hence, we should be stepping or pitching the culture after we have reached maximum cell density.

Now, a stir plate combined with continuous aeration is an entirely different topic.  However, that process requires us to sterilize (at least sanitize) another piece of gear.


Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: narcout on October 17, 2014, 06:34:34 PM
A stirred culture has to be stirred at a fast enough speed to create a vortex down to the stir bar in order to provide adequate aeration.  CO2 is denser than air, so there is very little in the way gas exchange in a flask after significant CO2 production has started.

Oh man, there was a long thread about this topic on the NB forum a couple of years ago that delved into partial pressures of gases, etc.  It got a bit heated as I recall.

The major advantage that a stir plate offers over merely shaking a culture until it is almost all foam immediately after pitching is that it keeps flocculent yeast strains from prematurely flocculating.

What about driving off CO2, is that worth anything?

Now, a stir plate combined with continuous aeration is an entirely different topic.

What about hitting a stir plate starter with a bit of oxygen prior to pitching?

Actually, I remember that Kaiser did some experiments on this topic. 

http://braukaiser.com/blog/blog/2013/03/19/access-to-air-and-its-effect-on-yeast-growth-in-starters/
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: S. cerevisiae on October 18, 2014, 05:09:49 PM
Actually, I remember that Kaiser did some experiments on this topic. 

http://braukaiser.com/blog/blog/2013/03/19/access-to-air-and-its-effect-on-yeast-growth-in-starters/

That experiment pretty much correlates with my hypothesis. 

This part of Kai's hypothesis is on the money. 

"yeast growth in wort is limited by available oxygen for sterol production.  That means that access to more O2 allows more cells to be grown."

However, the maximum number of viable cells that can be produced is limited by the maximum cell density per milliliter.

With that said, one thing that I am certain most readers will overlook in the experiment is the inoculation rate of 10.8 billion cells per liter.   That inoculation rate is a fraction of the number of viable cells that are available from the average White Labs vial (it's an order of magnitude less than that of a relatively new White Labs vial). 

To grow from 10.8 billion cells per liter to 250 billion cells per liter (which is above the normal maximum cell density of 200 million cells per milliliter), requires the culture to undergo log2(250 / 10.8 ) replication events.

Note: log2 is the logarithm base-2 function, which can be performed on calculators that do not support it by taking the base-10 logarithm of 200 / 10  over the base-10 logarithm of 2 (i.e., log(250/10) / log(2)) or the natural (base-e) logarithm of 200 / 10  over the natural logarithm of 2 (i.e., ln(250/10) / ln(2)).  This formula is the inverse of the basic exponential growth model after n replication events, which is cell_count_after_n_events = initial_cell_count x 2n.

number_cell_replication_events_kai_experiment = log(250/10.8 ) / log(2) = 4.53


To grow from 100 billion cells per liter to 250 billion cells per liter, the culture has to undergo log2(250 / 100) replication events.

number_cell_replication_events_fresh_white_labs_vial = log(250/100) / log(2) = 1.32

Stir plates appear to be yet another situation where the amateur brewing community has taken a technique that is rooted in science and generalized it to a point where the outcome from the technique no longer holds. In my humble opinion, little to nothing is gained by using a stir plate, stir bar, and a 2L to 5L Erlenmeyer flask at typical amateur brewer starter volumes. A stirred culture without continuous aeration offers no advantage over a well-shaken culture when propagating a White Labs vial, and a well-shaken culture has fewer possible sources of contamination. 

A cheap and easy solution for shaken 1L starters is a 1-gallon glass jug with a sanitizable cap (be careful when pouring hot liquid in a glass jug because most jugs are made from untempered soda lime glass).  For those who are not price sensitive, a 4L to 6L screw cap Erlenmeyer flask such as Corning model 4995-4L or 4995-6L can be a good investment if one takes care of one's gear, especially if purchased used.  A  4L to 6L screw cap Erlenmeyer affords one the advantage of being able to boil one's culturing media in the flask.   Larger starters will require a larger jug or flask (shoot for at least three times the starter volume).

Remember, the key to the well-shaken starter technique is using a vessel that is at least three times the size of the starter volume and shaking the starter until it is almost all foam after pitching.  Periodically shaking the starter during the first six to twelve hours can be beneficial.

Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: narcout on October 18, 2014, 06:01:12 PM
A stirred culture without continuous aeration offers no advantage over a well-shaken culture when propagating a White Labs vial, and a well-shaken culture has fewer possible sources of contamination.

Doesn't Kai's experiment show that the stir plate helps to aerate the culture?  I guess that is what I took away from the fact that the starter covered with an airlock grew less yeast than the starter covered with foil which grew less yeast than the uncovered starter. 

If no aeration was being provided by the stir plate, wouldn't you expect to see the same growth regardless of how tightly the flask was covered?  Maybe a repeat experiment with control cultures not on stir plates would be needed to really answer that.

Periodically shaking the starter during the first six to twelve hours can be beneficial.

If nothing else, I suppose a stir plate can do the shaking for you while you are sleeping or at work.


Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: denny on October 18, 2014, 06:53:46 PM
I know of a stir plate aeration study being done now by a homebrewer and a couple microbiologists.  It's appearing that there is virtually no O2 added from the stirring motion, but the results aren't complete yet.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: narcout on October 18, 2014, 07:37:21 PM
Cool.  I hope someone will post the results when available.  I suppose it doesn't really matter all that much, as long as you are pitching the desired amount of healthy cells.

In the meantime, I've got a Saison to brew (sans starter altogether in fact).
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: erockrph on October 19, 2014, 04:34:54 AM
This is starting to make me feel better about never bothering to invest in a stir plate. I may have to try the "shake to a froth" technique in one of my 3-gallon Better Bottles the next time I make a starter.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: denny on October 19, 2014, 03:42:55 PM
This is starting to make me feel better about never bothering to invest in a stir plate. I may have to try the "shake to a froth" technique in one of my 3-gallon Better Bottles the next time I make a starter.

I made shaken starters for years and felt like I got great performance. Then someone gave me a stir plate.  My starters are not only done sooner, but my subjective analysis is that the yeast performs better.  YMMV.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: S. cerevisiae on October 19, 2014, 09:56:32 PM
I made shaken starters for years and felt like I got great performance. Then someone gave me a stir plate.  My starters are not only done sooner, but my subjective analysis is that the yeast performs better.  YMMV.

There's no doubt that a stir plate results in reduced fermentation times.  A stir plate keeps most if not all of the viable cells in suspension (that's what it is designed to do).  However, getting a starter to ferment to completion sooner is not the goal of making a starter.  The goal of a starter is to increase viable yeast biomass, and no appreciable viable biomass is created after the end of the deceleration phase (which is technically the tail end of the log or exponential phase).   

With that said, my results have been the opposite of yours.  I have experienced no appreciable performance improvement since switching to using a stir plate.  What I have experienced are stressed yeast cultures (e.g., ale yeast strains throwing sulfur), which is why I started to question the value-add of a stir plate as used by most amateur brewers.  I am hoping to be able to find the time to test well-shaken at pitching time, continuously stirred, and continuously shaken starters over the winter.

Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: Stevie on October 19, 2014, 10:27:28 PM

...which is why I started to question the value-add of a stir plate as used by most amateur brewers.
Good thing I'm a homebrewer not an amateur brewer.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: S. cerevisiae on October 20, 2014, 12:26:45 AM
Good thing I'm a homebrewer not an amateur brewer.

Homebrewers are amateur brewers.  An amateur brewer is a brewer who brews sans compensation.

I personally do care for the terms "home brewing" and "home brewer."  Both terms carry negative connotations that date back to the days of Prohibition.  The hobby has grown well beyond the days of PBR malt extract, white sugar, and Red Star yeast.  However, that's the image that comes to mind when people my age and older who do not brew think of home brew.   
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: Stevie on October 20, 2014, 12:40:11 AM
Well I prefer homebrewer over amateur. To me amateur carries a negative connotation of inexperience and lack of skill. Tomato potato.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: morticaixavier on October 20, 2014, 02:26:24 AM
Well I prefer homebrewer over amateur. To me amateur carries a negative connotation of inexperience and lack of skill. Tomato potato.


remember, until they started letting pro basketball players compete, the olympics were an all amateur competition. The concept of amateur can actually encompass the very best of the best because there is no need to pander for pay. it essentially means one do does it for the love
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: S. cerevisiae on October 20, 2014, 02:51:15 AM
Well I prefer homebrewer over amateur. To me amateur carries a negative connotation of inexperience and lack of skill. Tomato potato.

Well, that's one definition of amateur.   However, most professions recognize the following definition:

am·a·teur

noun \ˈa-mə-(ˌ)tər, -ˌtu̇r, -ˌtyu̇r, -ˌchu̇r, -chər\

: a person who does something (such as a sport or hobby) for pleasure and not as a job






Title: HELP: WLP540 Abbey IV Attenuation
Post by: Stevie on October 20, 2014, 03:27:03 AM
I would give you amateur if another widely accepted word didn't exist. But we both agree homebrewer is appropriate, we just have different reasons to use one or the other due to our respective experiences with those that do not brew.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: egg on October 20, 2014, 08:50:36 AM
If only to bring this back on topic (!)...For my part, I reported here that my current 'Rochefort' was firmly stuck at 1.016 (OG 1.079).  Although this represents 80%AA, it's nowhere near what I'd hoped for with such a low mash, 15% sugar and theoretically ample starter.  Despite further rousing and 76F, it continued to drop bright clear with absolutely no movement.  It tastes far too full and 'sweet' as it is IMO, certainly not the 'digestable' quality we might expect of the style.

I racked the 'clear' beer to a secondary and repitched it with a 1L 1.040 active (13hr) DME starter of US-05 last night (at 72f).  I was not hopeful, but this morning (11 hours on) there is a new thin disk of kraeusen forming on top, which has warmed my amateur/home brewer's heart considerably! If it just shifted by 2 or 3 points I would be much happier I suspect, so I will be interested to see what happens.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: S. cerevisiae on October 20, 2014, 02:53:19 PM
I would give you amateur if another widely accepted word didn't exist. But we both agree homebrewer is appropriate, we just have different reasons to use one or the other due to our respective experiences with those that do not brew.

Amateur brewer is also equally appropriate.  In fact, one of the earliest publications dedicated to the hobby you call homebrewing was entitled "Amateur Brewer."  It was published in the seventies by Fred Eckhardt.  Fred is considered to be one of the godfathers of the movement.

By the way, many brewing clubs and associations outside of the United States have no problem whatsoever with the term "amateur brewer."  In fact, the Canadian counterpart to the AHA is called the Canadian Amateur Brewers Association.



Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: S. cerevisiae on October 20, 2014, 02:56:43 PM
If only to bring this back on topic (!)...For my part, I reported here that my current 'Rochefort' was firmly stuck at 1.016 (OG 1.079).  Although this represents 80%AA, it's nowhere near what I'd hoped for with such a low mash, 15% sugar and theoretically ample starter.  Despite further rousing and 76F, it continued to drop bright clear with absolutely no movement.  It tastes far too full and 'sweet' as it is IMO, certainly not the 'digestable' quality we might expect of the style.

Eighty percent apparent attenuation on a big beer is still very good. 
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: egg on October 24, 2014, 02:11:01 PM
Well it seems like I can cautiously recommend the US-05 repitch I did on mine.  It's down to just over 1.011 now (around 85%AA), possibly with tiny bubbles still rising (unless my sample was just degassing a little).  No noticeable change to the underlying taste, except the increasing dryness.  It was really going nowhere with the Rochefort yeast at 1.016, but this is more like it.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: ultravista on October 24, 2014, 04:44:26 PM
egg - what was your starting gravity?
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: egg on October 24, 2014, 05:18:20 PM
egg - what was your starting gravity?

1.079 (details in 7th post)
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: ultravista on October 26, 2014, 05:42:06 AM
Mine was 1.087 and it seems to have settled @ 1.020.
Title: Re: HELP: WLP540 Abbey IV Attenuation
Post by: egg on October 26, 2014, 11:23:35 AM
I guess it's just your call on what you do.  You've had it in there 7 or 8 weeks if I understand correctly, it's been kept warm and you used pure O2.  Personally, 1.020 is nothing like the digestible Belgian beers I've had and I'd risk a repitch rather than accept a different beer to what I intended, but just because it looks to have worked in my own, I don't feel empowered to suggest it will necessarily work in yours.  A forced ferment mentioned above would waste very little and give you a better idea.  I mean this helpfully, but mine is down to 1.010 today, 4 weeks fermenting and a week after the active repitch.  However, this beer will have to taste fantastic in a few months for me to go into a repeat brew knowing that I may well have to repitch again.  I don't have pure O2 and I could put the simple sugars later into the ferment, but other than that, it seems a problematic yeast to use.