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HOMEBREW Digest #4459
HOMEBREW Digest #4459 Fri 23 January 2004
FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
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Contents:
Victory/special roast... (Michael)
Re: Sanitation Practices and the common Homebrew Resources (Tim Cook)
A Pardon From The King ("Phil Yates")
Scottsdale brewpubs ("dave holt")
Re: Sanitation Practices and the common Homebrew Resources (Jeff Renner)
auto-brew ("Todd M. Snyder")
RE Propane cooker conversion to NG ("Mike Bronosky")
Sanitizing Questions (rickdude02)
Re: fusels & esters (part 1) ("-S")
Re: fusels & esters (part 2 of 2) ("-S")
Re: Scottsdale Brewpubs (Dustin Hauck)
120-Minute IPA Clone ("Eric R. Theiner")
Rinsing, sanitation (Calvin Perilloux)
Why you should know a bit more about enzymes ("-S")
Re: Clean Vs Sanitary ("Steve Dale-Johnson")
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Date: Thu, 22 Jan 2004 06:13:55 GMT
From: Michael <grice at berbee.com>
Subject: Victory/special roast...
First, thanks for the all replies. Thanks also for the restraint. I don't
believe even one of you called me an idiot, except perhaps when you were reading
the HBD. Like the idiot that I am, I left out important information--namely,
that I wanted to brew this weekend and wanted to use whatever substitutes I
could find locally.
For the archives, Marc suggested I use biscuit malt for victory malt, and
aromatic malt for special roast (or all biscuit if I were desperate). Jeremy
suggested toasting biscuit malt, since special roast is apparently a darker
version. Any errors transcribing those suggestions are mine.
Michael
Middleton
WI
------------------------------
Date: Thu, 22 Jan 2004 17:20:02 +1100
From: Tim Cook <Tim.Cook at Sun.COM>
Subject: Re: Sanitation Practices and the common Homebrew Resources
Pat,
I can not guess where your possible infection may have come from - it
sounds like you put (perhaps more than) enough effort into sanitising.
I did want to point out one thing - you should not need to sanitise
anything used to measure, mix, lauter or otherwise come in contact with
your wort or any of the inputs to your mash. This is because the wort
will be sterilised when you boil.
On brew day, the only things I (deliberately) sanitise are my fermenter,
my siphon, the stirrer I use to aerate the wort, and anything I used to
produce the starter.
As an indicator of how some brewers take risks that they deem
acceptable, I have read that plain cold unboiled tap water (as long as
it is chlorinated or similarly treated) is OK for rinsing out bleach or
caustic. I am now a brewer who accepts this risk. Life is too short to
eliminate all risks.
Regards,
Tim
Brewing in Melbourne (not the one in Florida), Victoria (not the one in
Canada)
On Thu, 2004-01-22 at 05:38, Pat and Debbie Reddyreddydpate wrote:
[...]
> The no-rinse agents available sound great but geez, do you know how long it
> takes a spoon to air dry? I've got a mash to stir every 15 minutes or so.
> If I stir, clean, sanitize, then air dry I won't be stirring for 30 minutes
> or more in some cases.
>
> And in the case of the "must rinse" sanitizers, is rinsing with hot (140*)
> tap water acceptable? I've read where it is definitely not, and I've read
> where it is perfectly fine.
[...]
------------------------------
Date: Thu, 22 Jan 2004 17:46:05 +1100
From: "Phil Yates" <phil.yates at bigpond.com>
Subject: A Pardon From The King
Steve Alexander states:
>Aww - not even close yet Wes. I have a soft spot for you and your partner
>and anyway it's bad form to "beat up" on a guy who can't put up a fight.
I'm going to assume here that Steve is referring to me as Wes' partner. Can
I say ladies and gentlemen, that I am absolutely chuffed? Steve has a soft
spot for me?
This conjures up images of an all mighty king sitting back (presumably in
an armchair) granting pardon to two poor souls rather than ripping them
apart with his vociferous tongue.
I don't know about Wes, but I think I'll take the money and run. After six
years of annoying him, Steve finally admits to having a soft spot for me. Do
what you like Wes, I'm not going to push my luck.
Now about that "Brave New Brewery" idea you thought up some years back
Steve, I'm thinking this experiment with kits is rather heading us in that
direction. If I recall, I think the concept was to have a full mash wort
supplied in kit form (with no flavour loss) and allow the brewer to simply
experiment with fermentation variations. I know Doc Pivo was thinking along
these lines, mainly because he had grown tired of the mechanics of a full
mash and boil. I did notice however, when he was out here, he hadn't at all
grown tired of drinking the end product. The bugger cleaned me out of three
months brewing!
So we're going to try some kit brewing using different sugars. Hmm, this
will be an interesting sperment. I like actually doing something and seeing
what effect it has on flavours. You can talk yourself right out of the
armchair with science. Let's go and do it.
Cheers
Phil
Still chuffed about that soft spot thing.
------------------------------
Date: Thu, 22 Jan 2004 00:16:10 -0700
From: "dave holt" <brewdave at hotmail.com>
Subject: Scottsdale brewpubs
Bob Barrett asks:
Will be in Scottsdale, Arizona next month for only two days.
What are the brewpubs I HAVE to visit?
I have the following as a preliminary list"
The Unlikely Cowboy
Papago Brewing
Never been to The Unlikely Cowboy but I can comment on Papago. Papago is a
fun place. 30 micro beers on tap that change daily. Usually 1-2 cask
conditioned beers too. A good place to sample other beers of AZ. In all
they claimed they have over 400 beers. Last week I looked in the coolers,
they had quite a selection of Belgiums. Papago has three signature beers, I
think they just added a 4th. The Barley Wheat Wine is popular, I personally
like the El Robusto Porter. The beers are contract brewed, so Papago isn't
really a brewpub. But I still highly recommend it.
A little further south in Tempe is Four Peaks Brewery. That is my favorite
place to hang out. My personal favorite is the Kilt Lifter Scottish Ale.
Also in Tempe, I would recommend Rio Salado. Hard to find, small place, but
the beers are always exellent. In Phoenix, I would recommend Sonora.
2 days isn't much time, the Phoenix area has quite a few brewpubs. It is
surprising how many I haven't been to. I'm fixing that soon. My stepson
turns 21 next month so I am organizing a pub crawl for the occasion. 15
passenger van, designated driver, and everything map out to see how many
brewpubs we can hit in one day. Maybe the Unlkely Cowboy will be added to
our list.
Dave Holt
Chandler, AZ
------------------------------
Date: Thu, 22 Jan 2004 09:25:56 -0500
From: Jeff Renner <jeffrenner at comcast.net>
Subject: Re: Sanitation Practices and the common Homebrew Resources
"Pat Reddy" <reddydp at earthlink.net> writes:
>The no-rinse agents available sound great but geez, do you know how long it
>takes a spoon to air dry? I've got a mash to stir every 15 minutes or so.
>If I stir, clean, sanitize, then air dry I won't be stirring for 30 minutes
>or more in some cases.
Well, Pat, you're making a whole lot of unnecessary work for yourself
if you are sanitizing things before the boil - that will pretty much
sterilize the wort. You could throw a dog turd in your mash and not
worry about an infection after a one hour boil. But don't serve me
the beer. ;-)
I never do anything more than clean things that touch the brew prior
to the chilling of the wort. I use a wooden mash paddle that
couldn't be sanitized short of high pressure steam, I imagine. I
just rinse it with hot water when I'm done. And I don't get
infections, or haven't for years.
Your garage may actually be less of a source of wort spoilage
critters than your kitchen, as long as you clean up spills. And in
the winter, at least in the north, the air should be very clean.
Some people have reported problems brewing in the summer due to
airborne contaminants, but I've never had that problem. I do close
the garage door when I'm chilling the wort, though, to keep the
breeze out.
>And in the case of the "must rinse" sanitizers, is rinsing with hot (140*)
>tap water acceptable? I've read where it is definitely not, and I've read
>where it is perfectly fine.
It depends on your water, but in general, it should be good. Again,
I have no trouble.
Clearly, it's important to clean and sanitize everything that touches
cool wort, but you don't have to be obsessive about it. I've had
good luck with using the back side of a clean paper towel from the
inside of the roll to set things on to drain after sanitizing. It
should be pretty darn clean from the heat of the manufacturing
process. (When I took first aid in Boy Scouts way back when, we were
told that the inside pages of a new newspaper was a good source of a
very clean surface - I've never confirmed this).
>I've been brewing for several years and haven't had much trouble with
>infection, possibly because of the strong yeast starters I pitch. But I may
>be tossing a 10 gallon batch of my favorite ale tomorrow night and I can't
>attribute the funk in this beer to anything but infection.
Have you asked others their opinion of the source of this funk?
(This is a good reason to belong to a local club - you haven't
disclosed your location, although your domain name "earthlink.net"
suggests that you are on this planet). It could be something else,
like unrinsed sanitizer. Is the beer in the secondary or is it
possibly in kegs - those poppets are notorious sources of infection.
Of course, you should check your hoses that you use to transfer
wort/beer. I boil mine. Plastic fermenters are more prone to hidden
contaminants than metal or glass.
Hope these thoughts help.
Jeff
- --
Jeff Renner in Ann Arbor, Michigan USA, JeffRenner at comcast.net
"One never knows, do one?" Fats Waller, American Musician, 1904-1943
------------------------------
Date: Thu, 22 Jan 2004 09:33:42 -0500
From: "Todd M. Snyder" <tmsnyder at buffalo.edu>
Subject: auto-brew
Hi Ed,
<Does anyone have a web page that has instructions for
automating their brewery (Automate your Brewery for
Dummies)? >
I don't have my system on the web, but I could send pics of what I do. It's
interesting that you brew in plastic with electric. I just switched over to
electric brewing myself!
I love the idea of using an old PC to control your system and have been
considering it myself. I would use a Parallax Basic StampII. I haven't
used it for brewing but have made an A/D convertor from a Basic stamp. For
analog to digital conversion, I interfaced a 12 bit, 8 A/D input chip (free
from Dallas) to the stamp, then hooked the stamp to the serial port of the
pc. Using a really simple Basic program, you can call the stamp and get a
a/d conversion on one of the channels and it sends the voltage signal on the
channel right back. I can send you a drawing of this and my QBasic code if
you like.
So say you have a thermistor (temperature variable resistor) on a 5 VDC
source so that the volt signal to the a/d pin is a function of the
temperature and is 0-4 vdc, your pc program would get the voltage from the
stamp, and then calculate the temperature. Then display it on the pc, or
log it to a file, whatever. The pc could also have a control algorithm
built in to turn on/off a heater using one of the i/o pins on the stamp.
The Stamp has like 16 I/O pins (0=off, 5 VDC = on) to control solid state
relays, the 8 channel A/D chip only uses like one or two of them so there's
lots left over. You could control pumps, heaters, refrigerators, anything
you like.
I don't know if this sounds too complicated, but I can assure you that if
you can program even just a little in Basic, it's very very easy to do and
I'm not a programmer.
I may or may not put this to use on my brew system eventually. Right now
I'm putting the finishing touches on a relay based system which automates
the vorlauf and runoff process. It allows me to dough-in, walk away, and
come back 3-4 hours later to a kettle full of wort. Made 7 gallons of boh
pils on Monday using it and all went very very well. In fact the efficiency
was way higher than expected for some reason, that's why 7 gallons instead
of 5.5.
My hot liquor tank (HLT) is already automated, it stays at a constant fill
level by a float switch and solenoid valve. It fills thru a carbon filter.
The built in heater is PID controlled. I put it on a timer about 4 hours
before I want to dough in, set at 180F. After doughing in I drop the
setting to 170 and walk away. So the HLT is sort of its own entity, it just
does its own thing. I need to add one more float switch to disable the
heater in the event that the water level is low so I don't burn down the
house.
Vorlauf and runoff/sparging is then automatic using water from the HLT.
Vorlauf occurs as the first household timer clicks on a peristaltic pump to
recirculate wort from the mash back to the top of the mash. This goes for
30 minutes.
Runoff/sparge occurs after the 1st timer turns off and the 2nd timer turns
on. BTW, these are just cheapo $6 Intermatic household timers. A second
peristaltic pump moves wort from the mash to the kettle. At the same time,
a brass float valve allows water from the HLT to flow gently onto the top of
the mash.
The nice thing about peristaltic pumps is that they don't require the use of
any valves to stop unwanted flow when they are turned off. Plus they are
nice and slow, to about 300mL per minute max. Search Masterflex on ebay,
they are pretty cheap there! I use #18 or #17 tubing, that means that the
pump head is a number 7017-00 or 7018-00 for instance. The 3rd and 4th
digits are the pump tubing size unless it's one of the quick loading types,
they do a whole variety of tubing sizes.
If at any time of the process either of two float switches are tripped, both
pumps will be stopped. One float switch is in a small reservoir on the
outlet of the mash tun. This prevent too much head from being drawn on the
mash in case of stuck mash. The second is on the kettle and turns off the
pump when the kettle is up to volume.
That's my system in a nutshell, no PC but very easy to use. No RIMS either,
there's no need really if you mash in an insulated tun.
Todd Snyder
Buffalo, NY
------------------------------
Date: Thu, 22 Jan 2004 09:25:30 -0500
From: "Mike Bronosky" <Mike at Bronosky.com>
Subject: RE Propane cooker conversion to NG
Currently I'm dating a person that use to be a marketing rep for Columbia
Gas, Mountaineer Gas and others. Recalling what she had told me about
getting more customers...
Check with your local gas company. I'm sure, if you talk to the right people
there, marketing folks, they would love for you to use more natural gas from
them. The marketing folks will probably not to know how to make the
conversion but they know the technical folks to ask.
Mike
- ---
[This E-mail scanned for viruses by Declude Virus]
------------------------------
Date: Thu, 22 Jan 2004 09:59:22 -0500 (GMT-05:00)
From: rickdude02 at earthlink.net
Subject: Sanitizing Questions
Pat Reddy asks some pretty detailed questions about sanitation
and sanitizing...
Pat, I'll answer the specific questions that you posed, then tell
you what works for me.
>What does it take to create a "clean and sanitary work surface"?
Well... clean it. Visible soil is what we call "medium soil" in the
business and what is not visible is "light soil." Use a detergent
or a spray and wipe cleaner (like Windex) regardless, and put
some elbow grease to it if it's medium or heavy soil, then clean
it one more time after the visible soil is removed.
And although some may say that spraying it down (don't use a
sponge-- sponges are very difficult to clean) and setting your
brew tools on your countertop is a good idea, I disagree. I keep
a bucket or a trough full of sanitizing solution that I drop my own
brew tools in. (A guy in our club found that wallpaper paste
troughs work very well for long items like spoons, racking canes,
etc.)
I do this because I am paranoid about air borne microorganisms,
especially because I have a "house infection" in my brewhouse
due to long term storage of grains in burlap sacks (that was a
BAD idea!). Even a few moments of an open fermenter inside the
brewhouse will result in some off flavors. If I carry the closed
containers outside, though, and transfer the beer out there, I don't
have a problem.
Which brings me to another comment-- your kitchen is probably
not as clean as you think it is. I have found that outdoor brewing
seems to have a much better track record in terms of maintaining
a sanitary result... but that's anecdotal only.
>When I clean and sanitize a piece of equipment, a spoon for
>example, and set it on the above mentioned sanitary surface, just
>how long could it typically sit there before I should sanitize it again?
If you use the method of storing your tools in sanitizer, then this
becomes a moot point.
>The no-rinse agents available sound great but geez, do you know
>how long it takes a spoon to air dry?
Honestly, the only time that you really MUST let one air dry is
when you are using C-Brite, because of the chlorine content. A
better term is "drip-dry," and an even better term is "drip... for
a few moments."
>I've got a mash to stir every 15 minutes or so...
You don't need to sanitize anything during the mash. The upcoming
boil will sanitize the resulting wort.
>And in the case of the "must rinse" sanitizers, is rinsing with hot
>(140*)tap water acceptable? I've read where it is definitely not,
>and I've read where it is perfectly fine.
I don't see any reason why hot water would not be preferable. Do
you have any idea why it would not be?
..............
As for what works for me... on brewday I start the brewing with no
concerns over sanitation. When I've got the mash going, I'll start
filling my fermenter(s) with a no-rinse sanitizer. I'll also allocate a
pot for odds'n ends... Oh, and I'll sanitize my CF chiller by running
boiling water through it, too.
As I'm coming to the end of the boil, I'll empty the sanitizing solution
into the odds'n ends pot, along with fermentation lock, etc. I'll fill the
fermenter, pitch the yeast (wiping the lip of my starter jar down with
sanitizer, first), and attach the fermentation lock. That's it.
When I transfer, I'll fill the ferementer with sanitizing solution again,
and use that to soak my racking cane and hose. I'll empty it into a
pot or trough, put the racking cane, tubing, new fermentation lock,
etc. into the pot/trough while I prepare for the transfer, then transfer,
using the pot/trough supply for dunking of items that I might need
(such as a glass for testing the progress).
I guess the key to my process is to submerge whatever I'm not using
when I set it aside.
Rick Theiner
LOGIC, Inc.
------------------------------
Date: Thu, 22 Jan 2004 10:33:54 -0500
From: "-S" <-s at adelphia.net>
Subject: Re: fusels & esters (part 1)
Randy Ricchi says,
>I brewed a barley wine ...
>
>The room I'm fermenting them in gets fairly cool overnight (low 60's)
...
>Monday morning ... kraeusen
>morning (Tuesday) ... absolutely no kraeusen
...
>Since both airlocks were still perking away like mad, I
>thought "uh, oh.... excess fusels killed the head".
Blaming this on fusels is premature and quite probably
incorrect.
>Are fusel alcohols the same as fusel oils?
The correct terminology is "fusel oils" or "higher alcohols". "Fusel
alcohols" is a misnomer. Yes they are the same thing. All simple alcohols
are foam negative, but I'm not aware that higher alcohols are any worse than
ethanol. They are certainly not as troublesome to foam as real oils, fats
or fatty acids.
>Fusel alcohols are larger molecules than ethanol, right?
Yes. The simplest alcohol is methanol w/ 1 carbon, ethanol has two carbons.
Others are more complex. Technically glycerol(glycerin) is a fusel oil too,
but it is flavor & body positive and we don't usually consider it as a
troublesome fusel. It's synthesis isn't like the "normal" fusels (see
below).
>Why is it that higher fermentation temps promote higher levels of fusel
>alcohols?
First the source of fusels requires explanation. Yeast consume amino acids
and small peptides as source material for protein and a few other ends. The
amino acids are first split, separating the common amine group from the
distinguishing carboxyl end. The amine remains as ammonia by taking a
hydrogen at the break. The carboxyl-head end adds a doubly bound oxygen - a
ketone group - at the break. The carboxyl ends pool as "keto-acids" in the
yeast cell.. The pools of ammonia and keto-acids are reassembled to form
amino acids and subsequently proteins.
To form fusels the keto-acid is decarboxylated - removing the carboxyl
group, leaving an aldehyde. The aldehyde is reduced to an alcohol by the
same enzyme process that converts acetaldehyde to ethanol. Yeast in
fermentation have a great need for reducing chemicals, like aldehydes, to
maintain their redox balance. Perhaps this is the evolutionary reason for
the decarboxylation step. The decarbox step also generates energy.
Keto-acids can also arise as yeast attempt to synthesize amino acids from
wort carbohydrate. This only happens when amino acid levels are low.
Generally fusels are created either when amino acids levels are high (so
keto's pool) and also when levels are too low and so ketos must be
synthesized. Early and late in fermentation usually. Usually the "late"
synthesis type creation isn't a big factor in beer fusels, but for a
barleywine it likely is.
The most important practical factor in controlling fusels is the choice of
yeast. The levels of the various fusels, both relative and absolute, found
in beer are specific to the yeast. You should choose yeast for hi-grav or
hi-temp brewing extremely carefully.
Next is the wort composition. High levels of sugar adjunct reduce the
amount of FAN(amino acids etc) relative to fermentable sugars. Unmalted
grains produce little FAN and contribute to this problem as well. In normal
gravity and composition wort, late amino synthesis source of fusels is a
minor factor, but in adjunct or unmalted grist wort it can be the dominant
source of fusels. High gravity fermentation creates a slightly higher than
normal demand for amino acids, as some have a role in allowing yeast to
tolerate the high osmotic pressures that exist in high gravity wort and
especially the high alcohol beer. As an aside, glycerol apparently has
some role as an osmoprotectant too and yeast will produce prodigious amount
of glycerol when fermenting high gravity wort - several grams per liter of
beer.
Aside from tuning the amount of FAN in wort, anything which promotes the
growth of additional yeast mass generally increases the level of fusels.
Excess oxygen or nutrients may do this, but generally the amount of growth
is, within a small range, determined by the amount of fermentable sugars and
the amount of yeast pitched. Underpitching causes greater mass growth and
produces more fusels. Overpitching presumably reduces final fusel.
The integrity of the yeast cell membranes which should prevent the "leakage"
of pooled keto-acids to locations where decarboxylation and reduction take
place is a factor. Cells low in lipids may produce additional fusel.
Oxygen, aeration ...sterols, UFAs; you know the drill. This is particularly
a problem at high gravity since the wort holds less O2 and the yeast undergo
added stress and may need additional lipids. For high gravity especially
I'd advise aerating or oxygenating the yeast fully *prior* to pitching and
also plan on a second pitching when the gravity is very very high - say over
1.075SG
Temperature is a puzzle. Boulton & Quain in BY&F note that temperature
causes faster yeast growth, but not greater final yeast mass, yet it causes
greater fusel levels. They suggest that high temperatures allow additional
membrane leakage of the keto acids.
Fermenting under top pressure of as little as 8psi, half an atmosphere, can
cause a substantial reduction in fusel levels, tho' it also slows the rate
of fermentation a bit.
In order of importance, yeast selection, wort composition and fermentation
conditions(temp&pressure) are the factors to consider in controlling fusels.
Of course really high temps can trump other factors - it's a matter of
extent too.
========
(more to follow)
-S
------------------------------
Date: Thu, 22 Jan 2004 10:36:05 -0500
From: "-S" <-s at adelphia.net>
Subject: Re: fusels & esters (part 2 of 2)
(continued)
>I remember reading about esterification of higher alcohols over time,
>and have always wondered if that meant that the higher alcohols are
>broken down into smaller chained alcohols (ethanol, maybe?) and esters.
>Is this so?
No - there isn't any "break down" of alcohols into esters. The
esterification converts the terminal hydroxyl (...C-OH) which is part of
every alcohol into a terminal ester group: (...COOH-C). This requires
energy and makes a somewhat bigger molecule.
>Are the esters created this way pleasant ones?
Ethanol esterifies to ethyl acetate - which it light and fruity but also
solventy. Other common fusels convert to isoamyl acetate - banana and
ethyl hexanoate - apples for example. Generally these are flavor positive
in ales and appropriate styles.
>Could that be
>why my belgians that initially didn't hold a head later held a
>beautiful, dense head after extended ageing?
No. Ester formation occurs primarily late in fermentation not in storage.
There are non-enzymatic paths to create esters but the levels are hundreds
of times lower than appear in fermentation. More likely, aging can reduce
levels of anthocyanogens which are foam negative.
This is a good point to discuss esters, since they result from alcohols -
both fusels and ethanol. The major means of formation involves an enzyme
catalysis of alcohols and acetyl-CoA. The amount of acetylCoA is a
determining factor in the creation of esters. There is always plenty of
alcohol. The acetylCoA is used in abundance in the creation of fatty acids,
but also for other biosynthesis, so we need to look into this to understand
where the acetylCoA is coming from and why yeast bother to esterify
anything. Also esterification may help yeast control the levels of
acetylCoA in cells.
Yeast, like everyone else make fatty acids 2 carbons at a time. The fatty
acids grow in length from C2, C4, C6 .. to around C20. The vast majority of
fatty acids in yeast are length C16 and C18 - similar to most plants.
Three fatty acids get attached to a glycerol molecule to form a
tri-acyl-glycerols - fats. Yeast can be 10% fat by weight and this requires
loads of acetylCoA, so this isn't some minor issue. Late in the
fermentation as the yeast growth slows the creation of fatty acids stops
dead. The levels of unused acetylCoA increase dramatically at this point.
One reason that may explain why costly esterification occurs at all is this.
The short-chained fatty acids, those under C12, are toxic to yeast, and some
of these are left over as intermediates when the fatty acid production
halts. Esterifying these reduces their toxicity and also makes them more
soluble. It appears that esterifying fusels is incidental to getting rid
of toxic FAs.
Anyway there are any number of studies that show that most beer esters
appear late in the fermentation, or in any case as yeast growth ceases,
fatty acid production halts, then acetylCoA levels rise and the machinery to
esterify alcohols and residual fatty acids is in high gear.
Factors the stall yeast growth will also create more esters,
under-oxygenating wort or wort deficient in growth factors for example.
Again the fact the higher temps create more esters is difficult to fully
explain. In part it's those d*mned leaky lipid membranes at work. This
creates more fusels and so more fuel for flavor esters. The abundant
ethanol doesn't have a very great affinity to the specific esterification
enzymes. Another factor is that the lipid esterification enzymes and
process is probably impacted by temperature, but this needs further work.
>Ahhhh,,, nothing like fresh material to worry about :^)
Proteins, fats, fusels, esters - that should be enough to think about.
Back to the origin - krausen & foam & fusels. I wouldn't be so quick to
jump to the conclusion that fusels are the problem here. Most hi-grav brews
will have more fusels than a low-grav brew. I find some mixes of fusels
particularly offensive which is probably why I am not a fan of huge gravity
as a genre. A few rare hi-grav beers are stunning, but most beers over 16P
have serious flavor problems IMO; excessive residual sweetness, huge and
obnoxious fusels, and awkwardly unbalanced sweet vs bitter flavors.
Proteins and humulones are significantly foam positive and relatively stable
throughout the fermentation, but viscosity of wort is extremely foam
positive and this disappears as fermentation proceeds. Also alcohols (all)
are foam negative beyond a low percentage. Wort is thus inherently more
foam positive than the resulting beer. I'd guess that is what you are
seeing.
-S
------------------------------
Date: Thu, 22 Jan 2004 08:32:47 -0800 (PST)
From: Dustin Hauck <tdhauck at yahoo.com>
Subject: Re: Scottsdale Brewpubs
> Bob Barrett asks
> Will be in Scottsdale, Arizona next month for only
> two days.
> What are the brewpubs I HAVE to visit?
My personal favorite is Sonora Brewing Co. (just west
of Scottsdale) It's a nice, friendy place with good
food and great beer. They usually have something on
cask too! Papago (in Scottsdale) has a large selection
but I do not believe they brew their own. They might
have some contract brews though, labeled as thier own.
They sell a lot of bottled beers and allow you to mix
& match your own 6-packs. Rio Salado (South Tempe) is
another good one with some nice Bock beers. Four Peaks
(North Tempe) makes a nice scottish called Kilt Lifter
(Bronze GABF '03). They seem to cater towards the
college crowd. All in all, I think Sonora is a "HAVE
to visit" place. It is definitely on my list whenever
I am in town. You can find any of these places on a
google search.
Dustin Hauck
QUAFF, San Diego
------------------------------
Date: Thu, 22 Jan 2004 11:45:20 -0500
From: "Eric R. Theiner" <rickdude02 at earthlink.net>
Subject: 120-Minute IPA Clone
I'm planning on trying my hand at the aforementioned clone,
but I have some questions for folks that can answer them...
First, how's the White Lab's High Gravity Ale Yeast (WLP099)?
Since I'm going for an abv of 20% or so, it seemed to be the
right choice, but are there any caveats to this yeast that any
of you have come across?
Second, my starting gravity is intended to be around 1.190.
I can't fit that much grain into my 10-gallon mash tun, so,
using ProMash as my advisor on this, I'll be starting with
29lbs of grain and planning on extracting ~7.15 gallons of wort
at 1.134. (This is based on a 15% evaporation rate.) I'll
make up the difference with 5# of DME. Does this seem
reasonable, considering my goal?
Lastly, rather than stand at the kettle and make an addition
every minute, I'm going to mash hop and hope for the best.
How can I calculate expected IBU's from mash-hopping?
Thanks for everyone's help, and if you have any other
ideas, please let me know!
Rick
------------------------------
Date: Thu, 22 Jan 2004 08:12:44 -0800 (PST)
From: Calvin Perilloux <calvinperilloux at yahoo.com>
Subject: Rinsing, sanitation
Pat Reddy writes in Thursday's HBD:
> The no-rinse agents available sound great but geez, do you
> know how long it takes a spoon to air dry? I've got a mash
> to stir every 15 minutes or so.
A mash? Really, there is no reason to worry about infection
in a typical mash. Any bacteria/yeast, even heat-resistant ones,
that do manage to get in there will be killed off shortly in the
boil that you'll be doing later. If you're sanitising things
for the mash, it makes me wonder if you're not thinking
through the sanitation routines in appropriate detail.
> And in the case of the "must rinse" sanitizers, is rinsing
> with hot (140*) tap water acceptable?
In circumstances like that, I usually have a pot of simmering
(or boiled then cooled) water available for rinsing, rather
than risk beasties still being alive in my hot tap water.
I would expect, though, that if you are on a chlorinated
or ozonated supply, it would be fine -- just get that
chlorinated stuff OUT as much as possible before using
the vessel. Chloramines especially can wreak havoc
with beer flavour, we are told.
If you are using a carbon filter to get chlorine out of
water, then don't use that water to rinse without boiling it,
lest the filter harbour bacteria. And if you are on a private
well, consider using the boiled water method unless you get
your water tested very regularly for bacterial activity.
Calvin Perilloux
Middletown, Maryland, USA
------------------------------
Date: Thu, 22 Jan 2004 14:02:05 -0500
From: "-S" <-s at adelphia.net>
Subject: Why you should know a bit more about enzymes
I happen to subscribe to the mystical notion that knowledge is
intrinsically good, but I appreciate this isn't widely held view among
N.European "beer" cultures and derivatives, so let me propose a few more
reasons ...
The 21st century is likely to do to genetics what the 20th century did for
electronics - make a practical everyday engineering process of a
fundamental science. We often see DNA presented as the "code of life".
The fact that genes primarily encode enzyme protein sequences is beyond
most popular descriptions. DNA may be the script, but enzymes are the
actors in this play. To be a literate resident of the 21st century
requires some understanding of this important technology. If being
"literate" isn't a driving force then consider James Thurber's great aunt
who believed electricity was leaking from all the outlets. Ignorance of
basic enzymology may be just as amusing to your grand-children.
The historical development of enzymology is closely bound to malt and
brewing yeast. Also brewing requires a basic knowledge of enzymology. One
can read enzymology either for the historical connections or for the
practical import of enzymes kinetics on the mash.
Early on alchemists determined that wine and beer contained alcohol or
'aqua ardens'. Later in the 18th century Laviosier and Gay-Lussac carbon
and put together the notion that sugar was converted to roughly equal
parts of ethanol and CO2 in the ferment. Laviosier died at the French
Revolution's guillotine in 1794 with the sentence that "the Republic has
no need of chemists and savants". It was already known that yeast played
some role in "the ferment" but the nature of yeast and it's exact role
required another century.
The 1800s debate over "the ferment" was the focus conflicting views of the
"vitalists", such as Pasteur, Schwann, and their detractors like Liebig
and Wohler. At about 1838 Schwann and Cagniard-Latour independently
proposed that yeast were living budding cells and that ethanol and CO2
resulted from their growth. This near-correct idea was soundly rejected
by the scientific community, and to be fair the evidence was only
circumstantial and early microscopy had produced a lot of unsound results.
In 1839 Liebig, a leading chemist, created a rather fanciful theory that
yeast was lifeless decaying matter and emitted "vibrations" that shook
sugar to pieces giving ethanol & CO2. You may recall seeing a paper, "The
demystified secret of alcoholic fermentation", describing yeast as little
animal seeds which consume sugar and defecate alcohol and urinate CO2.
This was a spoof by Liebig and Wohler ridiculing the vitalists and it
ruined Schwanns career.
Shortly before in 1833 it had been noted that water surrounding malt
contained some "active principle" capable of converting starch. They
called this "diastase" and promptly ignored it.
Pasteur typified vitalist belief in associating fermentation only with
living yeast. In 1858 he amplified and extended the work of Schwann and
Cagniard-Latour and declared that living yeast cells were responsible for
fermentation. Some of the more radical vitalists believed that
fermentation was a feature of living "plasma" and inextricably connected
to mysterious "vital forces". This completely contradicted the
proposition of Liebig. Tho' Liebig was forced eventually to agree that
yeast was living matter he never agreed to it's role in fermentation, but
insisted it's decay was the cause.
Despite Pasteur's modern depiction - he actually was well down the wrong
path too. Pasteur had attempted to extract the vital stuff that causes
fermentation from wine yeast. He was unsuccessful so he continued in his
insistence that living yeast was key and failed to consider the chemical
approach. Moritz Traube started to put the right pieces together in 1860
writing that chemical transformation in yeast caused the ferment. Also in
1860 Bertholet was able to extract invertase from yeast and apply it,
without the yeast to sucrose. He determined part of what Traube had
suggested - that the living cells create chemicals that cause the ferment.
Pasteur accepted the experimental result but rejected the more general
theory of Traube stating that invertase was only peripheral to
fermentation.
In the late 1890s along came the fabulous Buchner brothers (of funnel
fame). Hans was playing with brewing yeast at MunichU when his chemist
brother Eduard got interested in extracting the fermentation stuff from
yeast. Unlike Pasteur's wine yeast, brewing yeast gave up the goods and
the Buchners were able to ferment sucrose to alcohol using yeast extracts
with no live cells ! It was several years before this result was
accepted, after notables such as Max Delbruck and the Pasteur Institute
reproduced the result. Buchner was awarded the 1907 Nobel prize for
brewing without yeast, and the notion that vital forces was destroyed.
Here is a translation of Buchners paper - quite readable to a brewer.
http://bip.cnrs-mrs.fr/bip10/buchner0.htm
The stuff which cause this zymurgy(fermentation) was named zymase, and as
it was realized that there were many steps involved, the various active
components were referred to generically as 'enzymes'.
The odd bit is that some pig-headed scientists delayed the discovery of
enzymes for about 50 years. There was no special equipment or methods
needed to test Schwann's theory at the time he published. In particular
Pasteur demonstrated the obverse of his motto - 'chance bypasses the
closed mind'.
At the beginning of the 20th century enzymes had been "discovered" but
little was known about their nature. Buchner had determined these must be
proteins, but the means of activity was unclear. Fischer (of the Fischer
projection) had just puzzled out the geometry of sugars and then went on
to use yeast invertase and his knowledge of sucrose to test against
similar sugars. He was the first to recognize that enzymes are extremely
specific in recognizing their substrate - the lock and key model.
Adrian Brown of the school of malting and brewing in Birmingham
collaborated with Victor Henri. They added varying concentrations of
sucrose to fixed amounts of invertase and their data showed the rate of
hydrolysis increases only to a point with more sucrose. The enzyme
becomes saturated with too much sucrose. They postulated that the enzyme
E must temporarily complex with the substrate (sucrose) S, and after some
finite time the complex ES breaks down into fructose+glucose product P.
Soon after in 1913 German chemist Leanor Michaelis and a Canadian science
groupie Maud Menten got together to study invertase in Munich and produced
the big result in kinetics:
The reaction to for product P went like:
E + S => ES => E + P according to Brown and Henri.
with forward rates k1 and k2 assigned to this two steps process and also
these steps can reverse with rates kr1 and kr2.
In terms of rates they determines the increase of rate and the saturation
of enzyme with substrate concentration [S] is described by:
v0 = d[P]/dt = k2 * [E] * [S] / ( (kr1 + k2)/k1 + [S])
the usual form redefines the (kr1 + k2)/k1 term as Km - the Michaelis
Menten constant.giving
v0 = k2 * [E] * [S] / ( Km + [S] )
Note that the rate of product formation is maximal for very high
substrate concentration, where (( [S] / (Km + [S])) is nearly equal
to 1. At substrate concentrations well below Km,
(( [S] / (Km + [S])) is roughly equal to [S] / Km.
This allows experimental determination of k2 and Km by simple tests of
measuring rate of product formation at very high and also relatively low
concentrations.
A lot more could be said, both of the early and the more recent history,
of enzyme inhibition, denaturing and thermal rates, but that's all you get
in 8kb !
-S
------------------------------
Date: Thu, 22 Jan 2004 13:33:27 -0800
From: "Steve Dale-Johnson" <sdalejohnson at hotmail.com>
Subject: Re: Clean Vs Sanitary
RE: Pat's question on sanitation, I have little empirical and scientific
knowledge outside of the questions I've asked re. sanitizers I've used, but
what has worked for me I'll share.
<snip>What does it take to create a "clean and sanitary work surface"? ...
Is wiping down the countertop with a Star San solution, C-Brite, or Iodophor
with a damp sponge acceptable?
I have found that unless the surface is cleaned first, Iodophor (I liked to
spray with a spray bottle and leave wet) on an uncleaned surface was, I
think, responsible for a repeat beer infection and two tossed batches. What
I have been told since is that Iodophor cannot penetrate organic soils
(protein films, beerstone, kitchen gunk, etc), even if the surface _looks_
clean.
While Star San is supposedly superior as Five Star claims it successfully
penetrates organic soils to sanitize, I still prefer to clean thorougly
first. Yes, I'm a member of the anal brewers league, and yes I purge the
keg before _and_ the headspace after filling ;)'
What I do is to thoroughly clean kitchen surfaces with an abrasive
chlorinated cleanser (Comet), rinse thoroughly, dry and then spray with Star
San and allow to remain wet. For brewing gear, I use either Oxiclean (sp?)
or Diversol (a chlorinated pink detergent powder), rinse thoroughly, wipe
dry (so as not to dilute the sanitizer with rinse water) and follow with
Star San.
It might be anal, but no infections since I started this protocol. Bad
beer experiments, yes, but no infections.
<snip> When I clean and sanitize a piece of equipment, a spoon for example,
and set
it on the above mentioned sanitary surface, just how long could it typically
sit there before I should sanitize it again?
Five Star claims that StarSan has a residual action even after it's dry, so
I am a little more relaxed here. I usually re-spray and shake it off
without waiting any significant time before use. That said, I rarely even
rinse the spoon while mashing. Everything gets boiled soon enough.
<snip> The no-rinse agents available sound great but geez, do you know how
long it
takes a spoon to air dry?
That's why I like StarSan. Some like Paddock Wood claim 60 seconds for
sanitary use, Five Star says it kills everything in five minutes (is this
actually 'sterile'?? I don't know), but spray, wait, shake it off and use
it.
<snip>And in the case of the "must rinse" sanitizers, is rinsing with hot
(140*)
tap water acceptable? I've read where it is definitely not, and I've read
where it is perfectly fine.
I prefer following with a no-rinse sanitizer to be safe. They're cheap and
for most of us, the time invested in the beer is not.
Steve Dale-Johnson
Brewing at 1918 miles, 298 degrees Rennerian
Delta (Vancouver), BC, Canada.
------------------------------
End of HOMEBREW Digest #4459, 01/23/04
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