[narvin]

If one examines a Peter Austin designed/Alan Pugsley installed brewery closely, one finds a device that I like to refer to as a Yorkshire shower head.  This device is used to rouse and aerate the yeast during fermentation (yes, I said rouse and aerate the yeast during fermentation), as can be seen at time 0:12 in this video shot at the Blacksheep Brewery in North Yorkshire: http://www.youtube.com/watch?v=KJmLNj14C_w.   It can also be seen in the following video, which was shot a Peter Austin designed /Alan Pugsley built brew pub in Baltimore, Maryland: http://www.youtube.com/watch?v=HGIThQ7w0ls (the device is also used to aerate wort).

Yep, Steve Jones at Oliver's/Pratt Street Ale House in Baltimore (about a block from Camden Yards) still uses Ringwood and open fermenters in the 20 year old system... however, they're finally moving production out of the basement of the 1800s building to a dedicated brewery to expand capacity.  I hope they stick with open fermenters though.

He gets beastly atteuation and never has what I'd call "excessive" diacetyl for the style, and I think the rousing/aeration is definitely a big factor.

[Henielma]

Here in the Netherlands most starters are 100 gram DME and 1 liter water. This has a SG of almost 1040.

A true 10% w/v volume solution has an specific gravity (S.G.) of 1.040.  Mixing 100 grams of DME into 1L of water should result in a S.G. of approximately 1.036 because it is a 9% w/v solution.   If the solution is boiled for 15 minutes, the resulting S.G. should be between 1.038 and 1.040 after it has been cooled to room temperature depending on the evaporation rate.

You are right. After boiling the SG is a bit less then 1040.

[erockrph]

OK, time to put some of this new knowledge to practice. I have a 3L starter going now of 1.052ish wort using about 100mL of 3-week old slurry of WY1968 from a 1.045 batch. The batch I'm pitching into will be just under 3 gallons of ~1.088 Baltic Porter. It is right about 18 hours in and I still have a good krausen on the starter. But, despite all my reservations,  its's going in the fridge anyways. Wish me luck.

[S. cerevisiae]

OK, time to put some of this new knowledge to practice. I have a 3L starter going now of 1.052ish wort using about 100mL of 3-week old slurry of WY1968 from a 1.045 batch. The batch I'm pitching into will be just under 3 gallons of ~1.088 Baltic Porter. It is right about 18 hours in and I still have a good krausen on the starter. But, despite all my reservations,  its's going in the fridge anyways. Wish me luck.

Good luck!

How much slurry did you have available?

[erockrph]

OK, time to put some of this new knowledge to practice. I have a 3L starter going now of 1.052ish wort using about 100mL of 3-week old slurry of WY1968 from a 1.045 batch. The batch I'm pitching into will be just under 3 gallons of ~1.088 Baltic Porter. It is right about 18 hours in and I still have a good krausen on the starter. But, despite all my reservations,  its's going in the fridge anyways. Wish me luck.

Good luck!

How much slurry did you have available?

I had a lot of trub so it's all guesswork, but I had a total of 3 jars with the equivalent of 80-100mL of thick slurry (a blob actually, this is Fullers ) in each. I pitched the jar that seemed to have the most slurry of the three.

[erockrph]

OK, time to put some of this new knowledge to practice. I have a 3L starter going now of 1.052ish wort using about 100mL of 3-week old slurry of WY1968 from a 1.045 batch. The batch I'm pitching into will be just under 3 gallons of ~1.088 Baltic Porter. It is right about 18 hours in and I still have a good krausen on the starter. But, despite all my reservations,  its's going in the fridge anyways. Wish me luck.

Important consideration - when attempting to cold crash an active starter, make sure you take it below the low end of the yeast's active range. I had no idea that WY1968 would still ferment at 48F, but 7 hours later in my fridge it still had a thick krausen and was holding a couple of degrees above ambient with no sign of flocculation. Moved it to the 36F keezer and will check back in the morning.

[S. cerevisiae]

Many ale strains remain active down to the mid-forties.  Granted, they crawl at that temperature.  Four degrees Celsius (39F) is a good settling temperature.  I store my slants at 4C.  As you can see in the photos shown below, 4C pretty much slows yeast metabolism to a crawl.  When stored at higher temperatures, the condensation inside of the slant tends to cause the yeast on the surface to migrate to the outside of the media, which, in turn, produces gas that separates the media from the glass.  The result is that the media is pushed toward the mouth of the culture tube.

[69franx]

S. Cerevisiae, in these "shaken not stirred" starters, you shake after pitching the yeast into the vessel? I was working on building a stir plate, but have not gotten to it yet and am brewing this weekend and I would like to try this out. I need 453B cells for 6 gallons of 1.054 lager wort. I am now planning on pitching 1 WL833 vial to 2L of 1.03 starter wort. Crashing and decanting, then re-pitching the slurry to 2.5L of 1.04 wort. Does this sound like what you would recommend? Or am I off somewhere? This schedule, per yeastcalc leaves me with about 457B cells to pitch on Sun/Mon. What do you think? This all assumes about 82% viability of the vial when I purchase tonight

[S. cerevisiae]

S. Cerevisiae, in these "shaken not stirred" starters, you shake after pitching the yeast into the vessel?

I prefer to shake after inoculating the culture. Shaking before inoculating the culture is probably easier on the yeast cells.

The technique works better if there is significant head space in the starter vessel.  The vessel should be at least 3 times the volume of the starter.   I prefer to use a vessel that is 4 times the volume of the starter.   If you do not have access to a vessel that is 6 to 8 liters in volume, you can split the starter wort into two equal halves and use two one-gallon jugs.

Remember, we are talking about a serious shake, not a wimpy shake. One has to shake the starter until it is almost all foam; hence, this techniques requires a vessel with a screw-on cap that can be sanitized.  I have used a sanitized rubber stopper in a pinch, but one has to hold onto the wide end of the stopper while shaking to ensure that it does not come loose.

I was working on building a stir plate, but have not gotten to it yet and am brewing this weekend and I would like to try this out. I need 453B cells for 6 gallons of 1.054 lager wort. I am now planning on pitching 1 WL833 vial to 2L of 1.03 starter wort. Crashing and decanting, then re-pitching the slurry to 2.5L of 1.04 wort. Does this sound like what you would recommend? Or am I off somewhere? This schedule, per yeastcalc leaves me with about 457B cells to pitch on Sun/Mon. What do you think? This all assumes about 82% viability of the vial when I purchase tonight

A culture that contains 453 billion cells offers no significant advantage over a culture that contains 400 billion cells, as cell growth is exponential, not linear. 

6 U.S. gallons = 22.7 liters 

maximum_cell_density_for_22.7L = 22.7 x 200 billion =  4.54 trillion

replication_periods_453B_cells = log₂(4.54 trillion / 453 billion)
                                         = log(4.54 trillion / 453 billion) / log(2)
                                         = log(10.02) / log(2)
                                         = 3.32 (4) replication periods

replication_periods_400B_cells = log₂(4.54 trillion / 400 billion)
                                         = log(4.54 trillion / 453 billion) / log(2)
                                         = log(11.35) / log(2)
                                         = 3.5 (4) replication periods

If the wort is well aerated, one could get away with half of the pitching rate, as it only extends the number of replication periods by one.  The reason why 2x the ale pitch rate is suggested for lagers is too limit the amount of replication needed to reach maximum cell density; thereby, reducing ester production.  Additionally, I have yet to find hard data on how temperature affects doubling time with Saccharomyces pastorianus; however, as temperature affects metabolism, it has to affect doubling time.

[69franx]

Thanks, do those steps I put forth look good for starter OG? I will shoot for 400B cells then, and can split between either my 2&5L flasks or a 1G glass jug with lid to shake in. My steps will now be 1L of 1.03 and then 2.75L of 1.04 for a yield of approximately 402 by yeastcalc. I will shake it till mostly frothy, and post back. This will be my second lager, so not much to compare to, but I really appreciate your input

[S. cerevisiae]

Thanks, do those steps I put forth look good for starter OG? I will shoot for 400B cells then, and can split between either my 2&5L flasks or a 1G glass jug with lid to shake in. My steps will now be 1L of 1.03 and then 2.75L of 1.04 for a yield of approximately 402 by yeastcalc. I will shake it till mostly frothy, and post back. This will be my second lager, so not much to compare to, but I really appreciate your input

Please do me a favor and stop using yeast calculators.  In my humble opinion, they are one step above toilet paper when it comes to growing yeast cultures.  No yeast strain that I have ever used performs as these calculators would lead one to believe.  Experience is the best teacher when it comes to growing cultures, as no two strains perform exactly the same when pitched into the same composition and gravity wort.

With that said, one needs to determine where one is and where one needs to be when growing a culture.  When purchased from a shop that experiences good stock turnover, a White Labs vial usually contains at least 50 billion viable cells.  Starting with that number of cells only requires 270 minutes on average to reach 400 billion cells after the lag phase has been exited.  You should be thinking about pitching this starter 12 to 18 hours after it has been inoculated (or at least arresting fermentation by cold crashing it).

As an aside, I grow 4mls of yeast slurry to 200 billion cells in one pass.  Four milliliters of yeast slurry contains approximately 1/10th the number of viable cells that are available in the average White Labs vial when it is pitched.

[Stevie]

Asking people to stop using yeast calculators is a bit bold. While you may have the skill, equipment, and knowledge required, many of us do not. Sure yeast calculators generalize and make assumptions, but it is the best many of us can do. I for one have zero interest in buying a microscope, counting slides, dyes, and all the other equipment when a bit of software will get me close enough.

[narvin]

Please do me a favor and stop using yeast calculators.  In my humble opinion, they are one step above toilet paper when it comes to growing yeast cultures.  No yeast strain that I have ever used performs as these calculators would lead one to believe.  Experience is the best teacher when it comes to growing cultures, as no two strains perform exactly the same when pitched into the same composition and gravity wort.

With that said, one needs to determine where one is and where one needs to be when growing a culture. 

Is that not the point of a yeast calculator?

You can't blindly input numbers and expect every beer to come out perfect.  But for determining your pitching rate, it's a good starting point before you start adjusting the other variables (oxygenation, increasing/decreasing pitching rate, etc).  And when I've done cell counts, they haven't been so far off that it makes using it as a guide worthless.

[dak0415]

As an aside, I grow 4mls of yeast slurry to 200 billion cells in one pass.  Four milliliters of yeast slurry contains approximately 1/10th the number of viable cells that are available in the average White Labs vial when it is pitched.

What size vessel do you use for that pass?

[S. cerevisiae]

As an aside, I grow 4mls of yeast slurry to 200 billion cells in one pass.  Four milliliters of yeast slurry contains approximately 1/10th the number of viable cells that are available in the average White Labs vial when it is pitched.

What size vessel do you use for that pass?

A 4L screw cap Erlenmeyer, but I used to use a 1-gallon glass jug.