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Messages - tomsawyer

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1591
I've found that many more brewers have problems caused by a secondary than have received benefits from one.  One of the most frequent problems I encounter from newer brewers is beer transferred too soon and left with off flavors that the yeast most probably would have removed.  In addition, contamination induced during the transfer or slight souring caused by oxygen introduction that allows acetobacter metabolism seems to be another frequent problem that might have been avoided without a secondary.

This is my experience as well.  You would think the suspended yeast that is transferred would be enough to clean things up but apparently not.  It must be that the cake, even while its sitting on the bottom of the fermentor, is still metabolizing these compounds at a far greater ate than the suspended yeast.  Could be that the suspended "stragglers" are not as strong and the most active yeast drops promptly.  Its kind of surprising considering the relative surface area of a yeast cake versus suspended yeast.

I think its odd to do a secondary and then bottle.  Bottle conditioning just causes a new bloom of suspended yeast, undoing the week(s) of attempting to clear the beer.  Plus you might have to add bottling yeast which iwould have been there to begin with if you';d bottled after primary.  Bottled beer is its own secondary in my opinion.

1592
Let me ask this (to anyone who may know, and maybe I should submit it to "Ask the Experts"): I have pitched two yeasts to start fermentation in a beer -- one very flocculent yeast (S-04) and one that attenuates well (US-05). Will this beer ferment to the extent of the US-05, and then clump up and flocculate as well as S-04? Seems to...but I just might be biased on that opinion.
Multistrain fermentations are not new, in fact they used to be the norm until yeast strains were isolated. But to what extent can we regress and use two or more strains to acheive particular results?

If the whole premise of attenuation is based on the ability for a good portion of the yeast to stay suspended, then you'd think a good-floccing yeast like S04 would drag down its better-attenuating counterpart when it went and give you the attenuation of S04, just maybe with a lower ester level.

It'd be a good question to ask Chris White, they are selling more and more yeast blends these days and its not strictly a Sacch and a Brett combo.

1593
This might be a good time to mention that Chris White and Jamil Zainisheff are this month's guests in "Ask the Experts".  You guys might want to try directing some of these questions to them for their take on it.

I already submitted two Denny, I don't want to pester them to death.

1594
I don't believe there is a pronounced difference among the strains, especially if you don't exceed their alcohol tolerance.

English ale yeast will produce a higher AA in a tripel wort than trappist yeast will in a mild wort.

I am not sure I understand.  You are saying there is not a big difference in flocculation characteristics between yesat strains?  Or that there isn't a difference between them in terms of their reaction to running out of sugar?  Your example seems to indicate that there either isn't a strict relationship between flocculation and attenuation, or that there isn't a difference in flocculation and attenuation is in fact closely coupled to floc.

I do think a yeast cake is still metabolically active for some time, so maybe flocculation doesn't completely determine attenuation.

1595
General Homebrew Discussion / Re: Frozen Lager
« on: January 11, 2011, 08:40:54 AM »
I was worried that this was going to cause yeast autolysis, but it sounds like this isn't a factor.  I did rack off the primary cake to the keg so it wouldn't be a huge amount of suspended yeast.

I thawed both kegs and they are back in the fridge.  I'm going to tap into one of them soon, although I moved a fresh british bitter in when I took this one off and its going to be hard to take it back off, its a favorite of mine.

1596
While it might be true that sugars (or their absence) act as a signal for flocculation to occur, but it doesn't explain the pronounced differences between strains.  I think that is something that is bred into the strain via selection.

Seems like temperature would also be a factor, although I suppose the temp simply follows the sugar levels inasmuch as rapid fermentation (and the heat it generates) slows at the time the most abundant and most fermentable sugars become depleted.

1597
I think for an average ABV brew, sweetness is probably more a function of the sweet sugars that are crosslinked to proteins or other carbs, making them unfermentable while leaving the sweet moeity available for the taste bud.  Your crystals being stewed and dried probably provides a fair amount of crosslinking, as would a long boil or the reduction of a portion of the wort for a Wee Heavy.

Once you get into high ABV, limitation of the yeast could mean residual fermentables that would be sweet.


1598
... Because of this it is not the types of sugars that yeast can ferment that makes a difference but the way yeast behaves in fermentation. In particular flocculation, alcohol tolerance and how well it can metabolize maltotriose.
Kai

In the book Yeast, White says that flocculation is the most important determinant of attenuation.  I'd never really thought about that but it makes perfect sense, the longer the yeast is suspended and working the better it finishes the job.  He goes on to say that yeast strains have been selected for their different flocculation characteristics based on how and when they are harvested (bottom vs top, early vs late).  This simple concept has really helped me to better understand how to best utilize the various strains available.  Things like, you don't rush a highly attenuating yeast since it takes longer to drop out.  You might want to lager and/or fine it to get your best beer.  Or, rouse your fast-floccing yeast a bit early on if you think you want to be on the dry iside.

1599
General Homebrew Discussion / Re: Dental Crowns and IPAs
« on: January 10, 2011, 03:25:47 PM »
I brew a mean IPA and the secret ingredient is Orajel.  You quit drinking once you can't feel your mouth.

1600
All Grain Brewing / Re: Digestibility
« on: January 10, 2011, 01:14:02 PM »
Beano would help if its the undigested carbs, not the gluten.  Might be worth a test.

1601
All Grain Brewing / Re: Digestibility
« on: January 10, 2011, 10:20:10 AM »
I wouldn't discount the cause being maltodextrins, those carbs that aren't fermented by yeast.  In the large intestine bacteria can metabolize those sugars and produce gas.  Try a low mash temp and no mashout.  Since the beta-amylase only chews from the end of a starch polymer, you'll get a lot fewer of the trisacharides and limit dextrins.  When you favor alpha-amylase you get things being cut into lots of larger pieces that don't all get broken down into monosacharides.

1602
All Grain Brewing / Re: mash pH changes over time
« on: January 10, 2011, 09:08:28 AM »
I would suppose the generally accepted recommended pH ranges are taken early in the mash, so if there is drift upwards it really won't matter.  One might shoot for the lower end of the acceptable range, knowing it will drift up.  But the acceptable range is broad enough that it probably doesn't matter.  Since the pH is simply affecting the amylases' reaction rate, a few more minutes with a slightly lower rate accomplishes the same thing.  As long as you are allowing time enough for all the starch to be hydrolyzed to sugar, it won't much matter what the exact pH is.

1603
General Homebrew Discussion / Re: Help Me Tweak My Hefeweizen
« on: January 10, 2011, 06:28:08 AM »
I took James Lorden's advice and split a batch to ferment with 300 and 380.  I blended together to bottle and the graivty sample had an excellent flavor.  I couldn't tell about the tartness, will wait on carbonation for that.

By the way, I was surprised to see Wine Enthusiast magazine had a beer article in the December issue, their 25 top beers of 2010.  Ayinger Ur-Weisse was #7.

1604
General Homebrew Discussion / Re: Primary carboy and Secondary carboy
« on: January 10, 2011, 06:19:04 AM »
Three things to remember.  First, when an airlock quits bubbling theres still work being done in the primary, don't rack for several days after the end of bubbling.  Second, fermentation temperature is critical to making good beer.  Don't start off at 70F+, the heat of fermentation raises the temp another 4F or more and you end up with a winey beer.  Third pitch enough yeast.  Use the Mr Malty web calculator to figure that out.

1605
General Homebrew Discussion / Re: Dornbusch's Advice for Alt?
« on: January 09, 2011, 10:49:06 AM »
Where are you getting sinemar Denny?

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