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HOMEBREW Digest #5197
HOMEBREW Digest #5197 Tue 19 June 2007
FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
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Contents:
Fast Fermentation ("A.J deLange")
Brett and fermentables (Mark Beck)
Corn Mash ("John Kennedy")
Experiment (leavitdg)
Overpitching - not this time ! ("-s@adelphia.net")
Re: Re: Olive oil (stevea)
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Date: Fri, 15 Jun 2007 11:00:31 +0000
From: "A.J deLange" <ajdel at cox.net>
Subject: Fast Fermentation
I've had similar experiences to Bryce's fast ferementations most
recently with an Irish stout using White Labs London Ale strain. I
pitched the beer Monday evening and drank it with my dinner on
Wednesday. Now it fared poorly in a contest I put it into recently with
comments like "sligtly sour" and "tastes like Guiness" and scores in the
20's so if you don't like stouts like Guiness you may be dissapointed
but I do.
A.J.
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Date: Sat, 16 Jun 2007 10:55:33 -0700
From: Mark Beck <beckmk at whitman.edu>
Subject: Brett and fermentables
Anybody know of sweeteners that are definitely not fermentable by
Brett, lactobacillus, and the other creatures in a Flanders Red? I
want to add a little sweetness and I thought about lactose, but I'm
worried that it will be fermentable to these organisms--is it? I
assume saccharine is non fermentable, anything else you know of?
Mark Beck
Walla Walla, WA
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Date: Mon, 18 Jun 2007 10:41:42 +1000
From: "John Kennedy" <John.Kennedy at readybake.com.au>
Subject: Corn Mash
Hi Guys,
I am finally going to make an American Lager with 30% corn, I will be
following the guidelines from Jeff Renner, 30% malt to cracked corn, heat to
67c (153f) rest 20min, boil 30min, then add to main mash.
I was thinking about cooking the corn mash the night before then adding it
to the main mash some 8 hours later, I was thinking about saving some time
on brew day, but I have no experience in doing this, has any one done this
in the past and received good or bad results, thanks in advance if you are
able to help.
Regards, John Kennedy
Brisbane, Aus
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Date: Mon, 18 Jun 2007 09:29:04 -0400
From: leavitdg at plattsburgh.edu
Subject: Experiment
I just bottled, and sampled 2 brews that I made as a sort of experiment, and
wonder what the collective wisdom is on the differences that I perceive.
The yeast was the same with both "summer" brews: WLP007 English Dry Ale Yeast.
The only thing is that the first brew used a fresh vial, and the 2nd used the
same yeast cake when I transferred to secondary.
The recipes were exactly the same, the water, and procedures as well, and the
temperatures in fermentation were for all practical purposes the same.
Other than the yeast being used in its second generation, the only other
difference was that the first brew had 8 lb pils malt, and 2 lb corn, while the
second had 8 lb pils and 2 lb of rice.
The difference is, to me, striking. The first summer brew is noticeably hoppy
(.25 Fuggles at 120, .25 same at 60, .50 Cascade at 30, .25 Cascade at 15 ),
although not really a pale ale, just a somewhat hopped summer ale (IBU was
17.9).
Whereas, the second brew, the one with rice, was not very hoppy tasting at all,
and in fact seems to lean in the "malty"/ more sweet side of my taste buds.
My water is like Munich water, so in both batches I added some Gypsum in the
mash, as well as acidifying the sparge water.
I have the feeling that the second batch would taste less malty if I had used
only 1 lb of rice, but I don't know.
Anyone have any experience with this?
The final gravity, in both cases, was 1.012, so I am unsure as to why the later
brew is noticeably less hopped, and more "malty" to the taste.
Confused.
Darrell
------------------------------
Date: Mon, 18 Jun 2007 23:46:38 -0400
From: "-s at adelphia.net" <-s@adelphia.net>
Subject: Overpitching - not this time !
Bryce van Denderen
> I recently
> (heroically) performed two separate mashes on the
> same day yielding 10 gallons of stout wort (OG 1060)
> and 11 gallons of amber ale wort (OG 1050). I pitched
> a yeast slurry from a previous batch at a rate of 0.7 litres
> for the stout and 0.5 litres for the amber. The strain used
> was Wyeast 1056. Aeration was performed with pure
> oxygen for approximately 10 minutes as slowly as I
> could, and the pitching and fermentation temp was 18oC.
> To my surprise both fermentations reached an OG of 1012
> after only 36 hours. I have never seen fermentation proceed
> so quickly. My question is have I overpitched (probably),
> and what are the expected ramifications to the flavour
> profile of these brews??
>
Your pitching rate is reasonable, tho' I'll suggest that saturation
with pure O2 is a bit much.
Frankly I'll suggest that the common HB experience is to substantially
underpitch and then to get slow and trailing sluggish ferments and a lot
of yeast by-product flavors. This time you've pitched properly and
perhaps modestly over-oxygenated and gotten a very good result.
Don't fret over success; you've done very well. Most HBers eventually
do a back-to-back brew and re-use a fractional yeast-cake and then get
similar results to yours (a big surprise the first time).
The high O2 and limited growth required for completion can reduce
the levels of ester and maybe fusels - and that might not work for
some styles of ale. I doubt anyone will criticize your beer for
excess fermentation flavors. I suspect you wouldn't be using
WY1056 if you wanted a lot of yeast by-product flavor.
IMO one of the simplest improvements most newbies can make to
their beers is to pitch adequately (which means more than 5gm of
dry yeast in 5gal), cool their wort before pitching and then to
separate the yeast at the proper time. You get A+ on the first
two. Get rid of the yeast after the diacetyl is gone but before
you get any flabby yeast flavors and you've hit the trifecta.
You can repitch the yeast-cake from the 1.050SG amber but
I suggest you dump the yeast from the 1.060SG stout. High
gravity ferments leave yeast in a compromised state, not fit for
re-pitching. 1.052SG or a bit higher is a reasonable cut-point
- YMMV.
The 80% apparent attenuation 1.060 -> 1.012 is possible but
near the limit of attenuation for normal brewing techniques of
all grain/malt (no adjunct). You can brew quite nicely using a
good tongue in place of a hydrometer if you wish, you can't
really count on numerical result unless you invest in a lab
hydrometer (about $25USD) and learn to use it accurately (esp
for the FG where CO2 is confounding). Even then the error is
around +- 3% apparent attenuation. My point is that
underattenuation is a common newbie problem. You
clearly dodged that bullet (or else have a massive misreading).
I suspect your really like these beers once they are finished.
-S
------------------------------
Date: Tue, 19 Jun 2007 12:10:29 -0400
From: stevea <steve-alexander at adelphia.net>
Subject: Re: Re: Olive oil
Fred L Johnson writes ...
> It is without doubt that Taylor's adding oil to wort would initially
> result in the emulsification of the oil within the wort, probably by
> phospholipids from the grains and hops. This emulsion of triglycerides
> (triacylglycerols) would become a "sink" for the few nonesterified
> (free) fatty acids floating around in the wort and would effectively
> sequester most of these nonesterified fatty acids in the interior of
> the emulsified oil droplet. It is reasonable that the addition of oil
> actually decreased the availability of nonesterified fatty acids to the
> yeast, yielding the results reported by Taylor.
>
That's very insightful Fred, Thanks.
Yet the FAs from the malt glycerides do appear in the yeast,
particularly the
unsaturated ones, but saturated ones as well. In the same paper the authors
add various lipid elements to wort and measure the fermentation. Adding
just free FAs to the fermenter only caused a minor improvement in
fermentation, while the addition of triglycerides caused most of the yeast
growth improvement ! (control 3.5gm yeast/l, free-FA 3.6g/l, triglycerides
5.1g/l, total-mix, 5.4g/l). A lecithin addition was also fairly effective.
Adding free-FAs cause the beer to have higher levels of short chain FAs and
higher esters, while adding triacylglycerides reduced both below the
control !
> Another point regarding Taylor's study (which I have not read) is that
> the fatty acids referred to within the yeast must certainly have been
> overwhelmingly esterifed to sterols or glycerol. The presence of truly
> free fatty acids in cells is fleeting, and ...
Right - unlike the malt lipids, yeast lipids were prepared by direct
saponifacation via the method of Shaw. I assume this means dumpling
yeast into a strong caustic and then extracting lipids with solvents. So
only the component FAs and sterols can be measured.
> The presence of predominantly unsaturated fatty acids within
> the yeast probably merely indicates that the enzymes performing the
> esterifications favor the use unsaturated fatty acids over saturated
> fatty acids, not that they preferentially extracted unsaturated fatty
> acids from the oil.
>
In the lipid enhanced case the yeast had abt
37% PUFAs
18% MUFAs and the remaining
45% SFAs
at a level of 30mg/g of yeast
In the control case (no added lipids) it was
0% PUFAs
20% MUFAs
80% SFAs
at a level of 20 mg/g of yeast
The levels of short-chain FA (< C14) is lowered by the lipid addition.
The absolute level of longer SFAs (C14-C18) is very similar for both.
So yes it appears that the primary difference is that the lipid enhanced
media causes the yeast to include about 50% additional PUFAs on top
of the normal lipid content. That isn't to say that the yeast didn't
obtain
more SFA & MUFA from the enhanced wort.
> I reiterate: if one wishes to provide fatty acids to yeast, one
> shouldn't do it with oil. One should use a dilute solution of the salts
> of the free fatty acids (soap).
>
This sounds plausible to me, but the impact of free-FA additions vs
triglyceride argues that you are wrong. That the triglycerides cause
the positive effect. I believe (and I'd like to find that article on
yeast lipid uptake that Scandrett refernced ... I don't have a paper
copy) b/c it did describe the lipid uptake mechanism in some detail.
For some reason the glycerides are more effective then the freeFAs
(why?). Of course yeast would be far more likely to encounter
triglycerides than free-FAs in nature. Any thoughts Fred ?
My feeling is that a high PUFA oil (like flax oil) would be a much better
choice than olive oil for the obvious reasons. The amount of PUFA that
the Taylor ... yeast contained was about 11mg/gm of yeast or 1.1% of dry
yeast mass. So my previous estimate was that a 5gal, 12P beer will
terminate with 65-80gm dry weight of yeast and so this enhanced with as
much as 0.7 to 0.88 gm of PUFA. That would be equivalent to an
addition of about 7.5ml of olive oil (11% PUFA), or 1.1ml of flax oil
(75% PUFA) per 5gal. I'd rather add the 1ml of flax oil than the 7.5ml
of OO to avoid the potential of head-killing residual oils.
- ---
I received a nice clarification note from Matt Gilliland at New Belgium
Brewery. They add 300ml of olive oil to 4500l of thick slurry, and this
is subsequently pitched into 168000l of wort. I calculate this oil addition
is only 0.15% of the slurry yeast mass and around 0.03% of the final
yeast mass. Taylor et al got their yeast to incorporate 1,1% of yeast
mass as PUFA while New Belgium is only adding 0.003% PUFA as
compared to yeast mass. On an HB scale the NewBelgium addition
would be ( 20l * 300ml / 168000 l) only 36micro-l of olive oil per
5 gallon [1ml per 148gallon]. This seems far too small to me.
-SteveA
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End of HOMEBREW Digest #5197, 06/19/07
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