Copy Link
Add to Bookmark
Report
HOMEBREW Digest #1501
This file received at Sierra.Stanford.EDU 94/08/15 00:37:04
HOMEBREW Digest #1501 Mon 15 August 1994
FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
Rob Gardner, Digest Janitor
Contents:
Re: Dry Hopping/Keg Fermenting (Dion Hollenbeck)
Re: Waste Water, Hop poles (msadul)
Re: Phils Philler(TM) (Joel Birkeland)
How do Chicagoland brewers treat their water? (Jay Weissler)
More on Forfeiture laws ("Glenace L. Melton")
Hydrometer temperature correction ("William F. Cook")
hardness and boiling/chantrelles/Richard's beginner's guide (Algis R Korzonas +1 708 979 8583)
raking/Britain's "best" beer/beer engine (Algis R Korzonas +1 708 979 8583)
thermal air currents/gushers/Anchor Porter yeast guess (Algis R Korzonas +1 708 979 8583)
hot water kills plants (Sean Rooney)
Re: That fresh beer flavor/Closed systems/CHEAP Cornelius kegs ("Mark B. Alston")
Using Pure Oxygen to Aerate Wort (MJones)
specific gravity stuff (DGERTH)
Corrosion of 304 Stainless Steel ("Palmer.John")
Send articles for __publication_only__ to homebrew@hpfcmi.fc.hp.com
(Articles are published in the order they are received.)
Send UNSUBSCRIBE and all other requests, ie, address change, etc.,
to homebrew-request@hpfcmi.fc.hp.com, BUT PLEASE NOTE that if
you subscribed via the BITNET listserver (BEER-L@UA1VM.UA.EDU),
then you MUST unsubscribe the same way!
If your account is being deleted, please be courteous and unsubscribe first.
FAQs, archives and other files are available via anonymous ftp from
sierra.stanford.edu. (Those without ftp access may retrieve files via
mail from listserv@sierra.stanford.edu. Send HELP as the body of a
message to that address to receive listserver instructions.)
Please don't send me requests for back issues - you will be silently ignored.
For "Cat's Meow" information, send mail to lutzen@novell.physics.umr.edu
----------------------------------------------------------------------
Date: Fri, 12 Aug 94 10:01:19 PDT
From: hollen@megatek.com (Dion Hollenbeck)
Subject: Re: Dry Hopping/Keg Fermenting
>>>>> "Randy" == Randy M Davis <rmdavis@mocan.mobil.com> writes:
>> Stephen Lovett asked about a fermentation lock on corni kegs that
>> won't require modifying the keg.
Randy> I have not tried this because I brew 5 gal. Imp. batches and
Randy> the keg is too small for fermentation, but why not remove one
Randy> quick connect stem and push a piece of plastic hose over the
Randy> threaded stem. An airlock stem should provide a good seal when
Randy> inserted far enough into the other end. If the hose is just
Randy> long enough to accomadate both of the rigid parts, the airlock
Randy> should be well supported and not fall over.
I ferment in kegs so I know for sure. Here is a little treatise I
have written on keg fermentation. Since I have had about 6 people ask
me for it in the last week, it is probably worth posting to the HBD.
dion
Dion Hollenbeck (619)675-4000x2814 Email: hollen@megatek.com
Staff Software Engineer Megatek Corporation, San Diego, California
- --------------------------------------------------------------------------
Some notes on fermenting in soda kegs
=====================================
Both primary and secondary fermentation can be done in soda kegs. When
both primary and secondary fermentations are done in kegs, racking is
less prone to infection than other methods of fermentation because it
is done through a sanitized hose into a sanitized keg and all of it
done in a closed system pushed over by CO2. This means that you never
have to start another siphon again.
A non-obvious trick is to use liquid dip tubes (these are the tubes
attached to the liquid "out" valves - the ones the beer actually flows
through when leaving the keg) which are shorter than
standard length so that when you rack, the trub is left behind. The
length to cut off will vary depending on how deep a sediment layer you
usually get. I use 1.75" shorter than normal for the tube in a
primary fermenter and .75" shorter for the tube used in a secondary
fermenter.
I use a blowoff tube on the primary fermenter which goes down into a
bucket with about 3" of sanitizer solution. It is attached to the gas
in valve body which has been modified by removing the inside poppet
valve. The poppet valve is the little round thing in the center of
the valve body. When you remove the valve body from the keg and look
inside, yoy see a triangle with a rivet through it and a spring. This
is the bottom of the poppet. To remove the poppet from the valve
body, remove the valve body from the keg, place it threaded end down
on the floor and use a pin punch to push gently down on the poppet.
It will drop down and out.Just get some vinyl hose to fit snugly over
the valve body. If you cannot get a tight fit, use a hose clamp, but
I have never needed one. The size tubing I use is 5/8", but your size
may vary due to the diameter of the valve body (I have pinlock kegs).
When sanitizing for racking from primary to secondary, you not only
need to sanitize your secondary keg, but the transfer hose as well.
This can be done by filling the keg completely with sanitizer solution
and then sealing the lid. Attach your transfer hose to the liquid out
and open the free end QD (Quick Disconnect - the fitting your beer or
gas hose attaches to) fitting (I have made a special adapter for
this). Attach a source of hot water to the gas input and force
sanitizer solution through the transfer hose until it is completely
full and then close the free end. Stop transferring and let it all
sit full of sanitizer. When rinsing, be sure to use the same
technique with rinse water to rinse out both the liquid side of the
keg and the transfer hose. You might ask, why not just soak the
transfer hose in sanitizer? Well, you could, but using the hose to let
the solution run out of the dip tube and valve body sanitizes those
parts, which if you just fill the keg with sanitizer will not be
touched because they will be filled with air and prevent sanitizer
from entering.
Replace the poppetless primary gas valve with a valve body with a
valve in it and pressure the primary to 10psi. Purge the secondary
with CO2 and seal it up and pressurize to 10psi. Weigh the primary on
a scale and take it off. Put the secondary on the scale and leave it
there so you will know when the transfer is almost complete.
Attach a bleeder valve to the gas valve of the secondary. Bleeder
valves are commercially available and are basically a QD fitting with
a brass Tee in which are a pressure guage and needle valve. They
allow one to measure the *real* pressure in a keg (the guage on the
CO2 regulator only registers how much CO2 will be applied, not the
actual pressure at the destination). Attach the CO2 from your tank to
the primary and boost the pressure to 15psi. Spray off both liquid
valve bodies with bleach and then with water. Attach the transfer
hose to the primary first and then to the secondary. Beer will begin
to flow immediately.
Crack open the bleeder valve on the secondary until the pressure drops
down to about 7psi, back off the regulator pressure on the primary to
about 10psi. Allow the transfer to continue until the secondary
weighs about 5 lbs. less than the primary weighed.
Put your hand on the liquid QD on the primary and release the lock (on
pinlock, turn the ring, on ball lock, lift the collar) while keeping
your hand firmly pushing down on the QD to keep it fully engaged.
This will allow you to release the QD immediately when the hose begins
to suck air. Watch the hose closely and as soon as it sucks air,
disconnect from the primary. Reach over and close the bleeder valve
on the secondary. While you will usually suck a tiny amount of trub
up just as it sucks air, if you leave the transfer hose on after that,
the rush of air past the bottom of the dip tube will suck trub in in
ever increasing quantities.
Racking from secondary to conditioning keg is identical except that
you will have a regular length dip tube in the final keg.
------------------------------
Date: Fri, 12 Aug 1994 08:16:29 -0400
From: msadul@interactiv.com
Subject: Re: Waste Water, Hop poles
npyle@hp7013.ecae.StorTek.COM writes
> All this talk about hot water (from your chiller) killing the grass, bushes,
> etc., has me very skeptical. I've seen people trying to use hot water to
> kill weeds but I've never seen much success, even when they do it repeatedly.
Enter data point #1.
When I was brewing a batch (10 gal.) early in spring, there was still about
a foot of snow on the ground. The drainage area I usually use for washing my
brewing equipment (using the hot water from my immersion chiller) was iced
over, so I decided on a gravely patch next to the grass. Unknown to me at the
time, the ground under the gravel was frozen. All of my chilling water flowed
through the gravel, over the ice, under the snow and onto the grass. Later
in the spring I noticed a large, 1 sq yard, puddle shaped area of dead grass
in that area. Now it's the middle of August and the dead grass has been
replaced by a puddle shaped area of dirt. As far as I'm concerned, hot water
is an effective sanitizing agent for your grass and soil. ;-)
Continuing on with the thread on hop poles:
evanms@lcac1.loras.edu (Mark Evans) writes:
> I use a method I read in a hop article. I cut down a few weedy,
> sucker trees that grow in a nearby wood. (these are not significant
> varieties, locust, whatever) I make sure they are about 20 feet tall and
> fairly straight. I sink 1-2 6' metal fence posts in the ground and then
> secure the trunks to the fence post with sturdy romex wire (leave the white
Likewise, but my poles are 20-30 feet.
> insulation on) Twist tight. I run three baling strings up to the top and
> let the hops creep on up. They've gone way past the top this year, but it
> hasn't hurt their growth. When I get early crops--like this year--I
> un-twist the wire, lower the poles carefully with a friend, pick the cones,
> and raise again. The neighbors think I'm nuts. They think it is some sort
After setting the poles up in spring, I really didn't feel like taking each
one down a few times for hop harvesting.
I ran 1 string (Sisal, 75 lb. strength) to the top of each pole, through
an eye bolt and back down again (Ok, I put the string on before the
poles went up). This was working fine until two weeks ago. When I visited my
hops, (I only see them on weekends) I found my cone-filled-its-going-to-be-a-
bumper-crop-almost-ready-for-harvesting-and-its-only-year-two-growth Hallertau
in a crumpled heap on the ground. :( :( Down comes the pole, new twine gets
threaded onto the old one and the pole goes back up. No visible damage to the
plant itself. It seems the string broke at the top of the pole where it went
through the eye bolt. I've since purchased small pulleys (for next year).
To make matters worse, last weekend I found my Mt. Hood on the ground. Arrgh!
This time, two of the bines were a bit crushed. I think they'll be OK, though.
Question:
What kind of string should be used for hops? The nylon, polyprop, etc. ropes
look too slippery. Should I double (or triple) up on the current string?
There is no shortage of the stuff (I bought one of the LARGE, 2000 ft.,
economy sized rolls).
Or maybe running 9 bines up one string is a no-no?
Mike Sadul
msadul@interactiv.com
------------------------------
Date: Fri, 12 Aug 94 10:56:02 MST
From: birkelan@adtaz.sps.mot.com (Joel Birkeland)
Subject: Re: Phils Philler(TM)
todd boyce <tboyce@bohemia.metronet.org> wrote:
> I'd like anyone whom has used a phils philler bottle filler to
>give me there impressions on how they though it worked. Good or bad. There
>brass, more expensive etc. Do they perform better than anything else
>you've personally used, or are you disapointed?
I used a Phil's Philler for my first 17 batches, and it seemed to work OK.
(The gravity shut-off feature is a nice idea, but it doesn't work. To
get around this, you have to use a two-handed method with this filler.)
However, it broke apart just before filling batch #18, which forced me to
resort to just stopping the flow by pinching the bottling tube. I was
amazed to see that I could fill the bottles much more quickly and with
much less foaming using this "pinched tube" method than I could using the
Phil's Philler.
Later, I soldered my Phil's Philler back together, and tried filling
some beer bottles with water. I noticed a lot of entrained air in the
stream entering the bottles. I guess this could have been due to my
repair work, but I doubt it.
I think the Phil's Philler is cute, but I won't buy another one. On
batches #19 and #20 I used a homemade filler that I constructed from some
brass tubing I picked up at the local Ace hardware for about $3. The design
isn't perfected yet, but already it works better than Phil's, and in a few
iterations I figure I will have a decent filler.
Joel Birkeland "Phoenix, AZ: An oasis of ugliness in the midst
Motorola SPS of a beautiful wasteland"
birkelan@adtaz.sps.mot.com - Edward Abbey
------------------------------
Date: Fri, 12 Aug 94 13:02:29 -0500
From: jay_weissler@il.us.swissbank.com (Jay Weissler)
Subject: How do Chicagoland brewers treat their water?
I'm interested in knowing what water treatments Chicagoland full and
partial mashers are using for different styles of brew. Specifically,
1) What do you do (if anything)? This includes pre-boiling the mash
water, acid or chemical additions, tribal dances, etc.
2) Why? What effect are you looking for, deficiency being corrected
3) Style of brew
4) Mashing method (full vs. partial, infusion,step,decoction).
5) Satisfaction with method, advantages, drawbacks, other comments.
Of course, I'm also interested in the opinions of non-Chi-town
mashers. I'm just focusing on where I live and know the water best.
I'll post a summary.
TIA
jayw
------------------------------
Date: 12 Aug 94 14:15:58 EDT
From: "Glenace L. Melton" <71242.2275@compuserve.com>
Subject: More on Forfeiture laws
- -------- Forwarded Message --------
Subject: More on Forfeiture laws
Date: 12-Aug-94 at 10:51
From: Glenace L. Melton, 71242,2275
To: Glenace L. Melton,71242,2275
Gary Meier states that the police must prove in court that property they
have confiscated under the forfeiture laws was involved in illegal
activity. That is true if the defendant files an appeal. To file an appeal
he must post an appeal bond equal to the value of the confiscated
property. In the case of the homebrew equipment that would have been
reasonable. However, if the cop had coveted the homebrewer's car, say it
had been a Lamborghini or Rolls, that could well have been forfeited also.
The gentleman in Alabama who gets a thrill out of committing the felony of
homebrewing should do it outside his home, if he owns it. If he is
renting, his landlord should fear for his property. The theory of the
forfeiture laws (as I understand it, and I emphasize that I am not a
lawyer and this is based purely on experience and my own reading) is that
while a person has inalienable property rights, and the state must go
through due process to confiscate any property, property has no such
rights and if property is involved in a felony it can be confiscated. This
appears to be a reversion to animism, but has been approved by the U.S.
Supreme Court, unfortunately. Again, if this seems unAmerican, and it
surely is, flame your congressmen.
I am sure W VA is beautiful and has wonderful people. So do all the
southern and eastern mountains states. But their judicial systems suck. If
you want justice you have to get a spotlight.
[END]
------------------------------
Date: 12 Aug 94 15:17:33 EDT
From: "William F. Cook" <71533.2750@compuserve.com>
Subject: Hydrometer temperature correction
Chip Hitchcock asked about an equation for hydrometer correction.
I'm not a chemist, but I am an engineer who deals with water density
quite frequently, and here's my solution:
Given T in degrees F, the amount to ADD to the hydrometer reading is:
deltaSG = -2.6086e-9*T^3 + 2.0441e-6*T^2 - 1.3003e-4*T + 1.0991e-3
Or, if you prefer lookup tables:
Temp F Correction Temp F Correction
- ------ ---------- ------ ----------
40 -0.0010 130 0.0130
50 -0.0006 140 0.0158
60 0.0001 150 0.0188
70 0.0011 160 0.0219
80 0.0024 170 0.0253
90 0.0041 180 0.0287
100 0.0059 190 0.0323
110 0.0081 200 0.0360
120 0.0104 210 0.0398
I keep a plot posted on the wall in the brewery, and it seems to work well.
The derivation is as follows:
>From the "Handbook of Chemistry and Physics", CRC Press, 68th edition,
page F-5, an equation for the density of fresh water is as follows:
rho = (999.83952 + 16.945176*T - 7.987041e-3*T^2 -
4.6170461e-5*T^3 + 1.0556302e-7*T^4 -
2.8054253e-10*T^5) / (1 + 0.01687985*T)
where: rho = mass density of water in kg/m^3
T = temperature of water in degrees C
Calculate a table and divide everything by the density at 60^F (15.556^C)
to get the specific gravity. Then subtract from 1.000 to get the
correction. The fit presented above is good from 32^F to 212^F, and quite
close to the numbers provided by the equation in CRC (+/- 0.00003).
None of this accounts for thermal expansion of the instument, etc. as
pointed out by Manning Martin in #1433, but I believe it is accurate enough
for most homebrewing purposes. I'm not sure about it's accuracy above 170^F,
as I don't take gravity readings between mash-out and racking cooled wort.
I hope this is helpful to someone.
Bill Cook
HydroComp, Inc.
Team Dennis Conner
------------------------------
Date: 12 Aug 94 20:04:00 GMT
From: korz@iepubj.att.com (Algis R Korzonas +1 708 979 8583)
Subject: hardness and boiling/chantrelles/Richard's beginner's guide
Scott writes:
>bacteria, I wouldn't take any chances with *my* wort. In addition,
>by boiling you drive off chlorine, chlorophenols (if there are any,
>hopefully not) and get rid of permanent hardness. Sounds like three
>good reasons to me!
I'm sure Scott meant temporary hardness. Permanent hardness is primarily
due to Ca and Mg in the water, whereas temporary hardness is due to
Carbonates in the water. Boiling high-carbonate water (assuming there is
sufficient Ca in the water) will cause some Calcium Carbonate to
precipitate out, thereby reducing the overall hardness of the water.
I'm sure this is what Scott meant.
*********
Henry writes:
>With all the rain here in the mid-Atlantic, chanterelle mushrooms are
>rather plentiful. I think they'd be better served with beer than as an
>ingredient in beer. However, I have heard of a chanterelle licquor. So --
>has anyone out there ever heard of a mushroom beer (that is, one using
>edible mushrooms rather than those that get you high. I presume the latter has
>been attempted & I really don't want the recipe if it has).
Darn... lucky you. Yes, as a matter of fact, I've heard of and tasted
chantrelle beer. Randy Mosher made it and basically, if I recall correctly,
it was 1 pound of chantrelles, soaked in 1 fifth of vodka for a month (don't
recall exactly, but I believe a month is right). Then the liquid is
strained off and added to bottles of beer at bottling time.
*********
Richard has been posting installments of his "beginners [sic] guide
to advanced and all-grain brewing. Someone (sorry) has posted a
possible use for this body of work, namely to explain brewing to
non-brewers. If this was Richard's intent, then with a few corrections,
it would do the job, but if the intent was to teach beginners how to
brew all-grain, then it certainly falls short. There is just not
enough information on the equipment or detail on the mashing process
to get a beginner brewing all-grain. Also, if they are already a
brewer, then it should be assumed that they already know much of
the info that is presented. Really, I think it's more of a thumbnail
description of brewing for non-brewers, not a how-to-all-grain
as it was initially presented.
One thing that started me off disliking the post was all the emphasis
on alcohol in the introduction. Alcohol was mentioned 8 times in
the 9 sentances of the introduction. It makes it sound like alcohol is
the most important reason for making beer. No mention of economy, quality,
better flavor, the pride in creating something yourself or the ability
to create beers that are unavailable commecially (either because you live
in a beer wasteland or because curry beer doesn't have mass appeal).
Also, check the definition of zymurgy.
>In ancient times, the only source of sugar readily available was to be
>found in the hives of bees.
I'm afraid not. Even in ancient times, they realized that they could
make (what turns out to be) a fermented beverage from grains.
>Warmer temperatures (over 153 degrees Fahrenheit or so) encourage
>the type of enzymes, called alpha enzymes, that convert long chains
>of starches into medium length chains of sugars, called dextrins, which
>don't ferment very well, but are necessary for a well made beer.
>Temperatures below that encourage the beta enzymes, which convert
>the chains of dextrins into fermentable sugars. In order to get a good
>balance of fermentable and non-fermentable sugars, we seek to achieve
>a balance of temperature of around 150-153 degrees Fahrenheit.
Not quite. The key to higher mash temps making more dextrinous wort
is that beta amylase is denatured quickly at higher temperatures (the
higher, the quicker). At lower mash temps (148F, 149F, 150F...) both
alpha and beta amylase cut starches up into fermentables. At higher
temps (158F, 157F, 156F...) beta amylase is quickly denatured and only
alpha amylase is left to work on the starches. Alpha amylase is limited
in what it can cut up on the starches and thus a less fermentable, more
dextrinous wort is the result. Also, the style should dictate how
dextrinous the wort should be -- a highly dextrinous Belgian wit would be out-
of-style, where a very thin Scotish export would also be uncharacteristic.
>Other types of malt, referred to as under-modified, or lager malt,
>are of course, less well modified. This means that the malting process
>has not proceeded along as far as is the case with the well-modified
>malts.
Not the malting process, but the germination process has not proceeded as
far in undermodified malts, but most malts these days (yes, even lager
malts) are fully modified.
>The starch tends to settle to the bottom of the tun where it is converted
>to sugar and drained away. The grain husks, which tend to float away,
>will then settle to the bottom of the tun, forming a filter bed to work in
>conjunction with the filtering properties of the slotted PVC pipe.
No, the starch and the husks don't really separate, but rather the whole
mash is a sort of porridge in which the reactions take place.
>away, while new water is allowed to flow through the grains. This
>sparge water should be no warmer than 170 degrees, as water hotter
>than that will leech out bitter oils and resins from the grains,
>potentially ruining an otherwise perfect batch of beer.
No again. If you are going to mention the temperature, then you had
better mention the pH also. It's the pH and not really the temperature
that causes the leeching. And I believe you're thinking of hops when
you write "oils and resins" -- what you leech from husks is tannins.
>water only serves to dilute the grain bed, resulting in a loss of enzymes.
>The other method of introducing heat to the mash is to remove some of
>the liquid from the mash. This liquor is heated up, and then returned
>to the mash. This process is called decoction mashing, and is a technique
>used in program temperature mashing.
Decoction mashing (not the only method of program temperature mashing, BTW)
involves the removal of the *thickest* portion of the mash, not the
liquid. Removing the liquid and boiling it will result in the loss of
enzymes that you were worried about losing in the previous sentance.
Finally, diluting the grain bed does not result in a *loss* of enzymes.
Al.
------------------------------
Date: 12 Aug 94 20:25:00 GMT
From: korz@iepubj.att.com (Algis R Korzonas +1 708 979 8583)
Subject: raking/Britain's "best" beer/beer engine
Jim writes, regarding rakes running during the sparge:
>Well, now we have 6/8 data points from British breweries. Now we need to
>get samples from German, Belgian, Swiss and Checz breweries to see what they
>do! I have also been asking brewers this question and often the answer is
>"I run em every 15 minutes for about 2 minutes then turn em off", or
>"I run em a bit in the start, then let em set until halfway through and
>sometimes drop the height as the lauter proceeds". I got a paper from
>Rich Fortnum who attends the Malting, Brewing & Distilling Science program
>at the Heriot-Watt University, Edinburgh, Scotland. In this paper, they
>did studies on controlled procedures in Weizen production. One of
>the interesting points was the specific detail of height of rakes and
>speed of revolution in the lauter tun. If I recall, the rakes were idle
>until about 50 mins into the lauter, then they were progressively rotated
>faster and deeper for the remainder of the lauter. Just goes to show
>different strokes for different brewers/breweries/styles/malts.....
Agreed. Actually, now that I'm back to driving on the right and have started
sleeping past 3am CDT, I recall that it was 5 breweries (had 7 scheduled, but
missed two due to travel delays). I believe that I posted this a few weeks
ago, but it is relevant to the current discussion, so perhaps I'll repeat it:
in Hough's Biotechnology of Malting and Brewing, he writes that, in general,
rakes are necessary for decoction mashing and usually not used for infusion
mashes. The reason being, that during the decoctions, all the trapped air
gets boiled out of the mash and thus the mash loses it's buoyancy.
Theoretically speaking (based on channeling in soil) the ways I could see
raking increasing extraction would be:
1. if the mash was extremely sticky either due to glucans, big proteins or
being too cool (picture water trying to go through clay) or
2. if the runoff was being taken from localized areas i.e. just from the
center or just from a small number of points (let's say it was just from
a single point in the middle of a large, wide lauter tun -- there would be
pools of relatively stagnant runoff in the corners -- the sparge water
would take the path of least resistance and the corners are not on that
path).
Granted, this is all theoretical and does not account for many factors
(mash stiffness, for example). I must admit, however, that I personally,
have never made an all-grain wheat beer, never have done a decoction mash,
never had a set mash and always resisted stirring the mash during runoff.
Perhaps I'm just trying to justify my own biases <-- not good science!
>So, Algis, what was *the* best beer on the trip, and did you
>return with a beer engine?
Given that I was at the Great British Beer Festival but that most of the time
I was on my own (i.e. I was not with one or two other tasters so we could
share a half pint) I only tasted a fraction of the beers available to me.
Nonetheless, I critically evaluated well over 120 different beers and of those
the three that stand out as the very best IMO were Jennings Bitter,
Gales HSB and Timothy Taylor Landlord (which won Champion bitter). Almost
all the ales I tasted were good to excellent, but what made these three the
best was their complexity. Many malt and hop flavors intertwined throughout
the palate on these beers -- each sip was a new experience, especially the
Landlord. Only one beer was judged poor and one undrinkable (Edinburgh's
Rose Street Brewpub Auld Reekie 80/- and 90/- respectively) and these
were AT the brewery!
Return with a beer engine? No, I'm afraid I bought two.
Al.
------------------------------
Date: 12 Aug 94 20:28:00 GMT
From: korz@iepubj.att.com (Algis R Korzonas +1 708 979 8583)
Subject: thermal air currents/gushers/Anchor Porter yeast guess
Erik writes:
>When we prepare agar plates for bacterial cultures in the lab we heat the
>sterile agar until it is liquid and pour it immdiately into the dishes.
>This is done in the presence of a lit bunsen burner which cretes a thermal
>air current that theoretically keeps bacteria from falling into the dishes.
I've read this before and don't believe that working near a lit bunsen burner
can keep bacteria away from your plates. Can someone explain to me why it
would? The way I see it is the heat rising from the burner will cause upward
air currents in the general vicinity of the work. The rising air must be
replaced -- from where? From the other parts of the room. I think that
the air currents will draw air (and possibly settled dust/bacteria) INTO
the work area from below and from the sides, no? Since the flow is not
necessarily going to be laminar (it will swirl) wouldn't it just be better
to work in a small, draft-free room?
**********
Seth writes:
>I'm a newbie homebrewer currently on my third batch. I've used Edme dry
>yeast on both the first and third batches, and noticed the same
>behavoir (fermentation goes strong for ~1day then just about stops). I
>don't have a hydrometer, so I don't know what the gravities are/were.
>For the first batch, I bottled it after two weeks. It turned out mildly
>carbonated, but the yeast aparently ``woke up'' after two months. On
>the final bottles, the dimple in the cap popped out, and the beer was
>way over carbonated. It didn't gush on opening, but it was like pouring
>foam.
What you've got is an infected batch. The primary yeast did it's work
in the first day. Either a wild yeast ate the bigger sugars that your
primary yeast could not eat or a bacteria cut up the bigger sugars into
smaller ones that the primary yeast could then eat. Recheck your sanitation
(summer is a tough time to avoid infections, BTW) and possibly consider
a different yeast. Edme *used* to have a reputation for having wild yeasts
and bacteria mixed right in, but they may have cleaned up their act along
with the other dry yeast manufacturers.
*********
Dave in Sydney writes:
>anyone know if Anchor uses the same yeast for
>their Porter as they do for the illustrious Steam beer?
I had heard that Anchor had switched from a lager yeast to an ale yeast
on the Porter, but that they were dissatisfied with the results and
went back to the lager yeast. I don't know if any of these ale yeast
batches were commercially sold. However, my suspicion is that if
Anchor is using a lager yeast for their Porter, then it's very likely
that it is indeed the same as the Steam Beer yeast, which is available
as Wyeast California Lager (#2112).
Al.
------------------------------
Date: Fri, 12 Aug 94 14:36:23 -0600
From: Sean.Rooney@uic.edu (Sean Rooney)
Subject: hot water kills plants
I regularly use the boiling water left over from canning to kill weeds
growing in the cracks in my driveway and sidewalk. If you add some salt to
the water they don't come back. It's fun to watch the leaves turn bright
green as the weeds are cooked alive.
Sean
------------------------------
Date: Fri, 12 Aug 94 15:10:05 MDT
From: "Mark B. Alston" <c-amb@math.utah.edu>
Subject: Re: That fresh beer flavor/Closed systems/CHEAP Cornelius kegs
Teddy Winstead asked:
(Related to first question) Is anyone using the closed-system
fermenter techniques outlined in the Zymurgy Gadgets issue? This
system is based on using one cornelius keg for primary fermentation
and carbonation, and a second cornelius keg for lagering, storage, and
serving. The argument is that the beer is never exposed to air until
it is served. I personally beleive in it, but I'd like to hear from
sceptical people as well as those that have tried this to hear what
they do or don't like about it.
I have been using a corny keg to ferment in for about 10 batches.
Here are a few suggestions I have for using the keg in this manner.
Contrary to what the Gadgets issue suggests I don't suggest cutting
off the long "out" tube. I use a copper end cap and 1" of copper
tubing placed over the end of the dip tube to keep from sucking up the
yeast sediment I then file some "v" grooves into the dip tube to allow
flow to continue if the end cap is sucked onto the dip tube. In this
way the keg can still be used as a serving vessel by simply removing
the copper tube setup.
For a blowoff system I simply remove the poppet from the gas end and
remove the valve and spring from a gas quick-connect. Then I attach
4' of tubing to the quick-connect. Many people have warned that you
could get a clogged blowoff tube this way, but I have found that if
you make certain that no hop leaves make it into the keg that there
are no problems with this method.
For me the biggest benefits of using this method are the ease of
racking the beer into the serving tank, and the ability to drop the
yeast out of the beer by placing the fermenter into an ice water bath
prior to racking. Furthermore, contrary to popular opinion, the keg
is easier to clean and sanitize. I can get my arm into the keg to
scrub it clean, which is impossible with a carboy. And sanitiation is
simple to achive with a couple of gallons of boiling H2O.
YMMV,
Mark Alston
(c-amb@math.utah.edu)
------------------------------
Date: Fri, 12 Aug 94 16:24:25 CDT
From: MJones@swri.edu
Subject: Using Pure Oxygen to Aerate Wort
Dear Homebrewers:
I recently got a good deal on a medical oxygen tank and regulator. I
would like to use pure oxygen to aerate the wort to give the yeast a good head
start. The two questions I have are:
1). Can I oversaturate the O2 content of the wort using pure O2?
2). Should I still put a bacterial filter in-line between the O2
tank and wort?
Any input would be appreciated.
Cheers,
Mark Jones
mjones@swri.edu
------------------------------
Date: Fri, 12 Aug 1994 16:01:40 -0600 (MDT)
From: DGERTH@LIMS1.LANL.GOV
Subject: specific gravity stuff
Howdy Folks,
Here's some info on specific gravity. It seems to be popping up frequently
lately, so I put together a mini FAQ. Any questions or comments, please
email me direct at dgerth@lims1.lanl.gov.
1. Specific gravity is defined as the ratio of the mass of a liquid to the
mass of an equal volume of pure water, at a specified temperature. Most
hydrometers are calibrated (in the U.S., at least) at 60 F, which is
15 5/9 C. Since the density of water decreases from 4 C on up, a factor
is required to correct the observed sp. gr. to what would be observed at
the reference temperature (There's a few assumptions and other factors,
but for all practical purposes.....). This factor can be calculated from
data on the weight of 1 gram of water at various temperatures. Using 60 F
as the reference temp., these factors are:
Temp, F Correction Temp, F Correction
60.0 0.0000 93.2 0.0046
62.6 0.0002 95.0 0.0049
66.2 0.0006 104.0 0.0067
69.8 0.0010 113.0 0.0088
73.4 0.0015 122.0 0.0110
77.0 0.0019 131.0 0.0133
78.8 0.0022 140.0 0.0158
80.6 0.0025 149.0 0.0185
82.4 0.0027 158.0 0.0212
84.2 0.0030 167.0 0.0242
86.0 0.0033 176.0 0.0272
87.8 0.0036 185.0 0.0304
89.6 0.0039 194.0 0.0337
91.4 0.0043 203.0 0.0371
212.0 0.0407
These numbers should be pretty close to those supplied with your hydrometer.
Simply add the correction to the observed sp. gr. For temperatures not in
the table, you can use (for temps > 60 F only!):
factor = 9.933E-7 * T^2 + 1.956E-6 * T - 4.065E-3
This will get you close enough that other errors are predominant.
2. Suspended material exerts an effect on sp. gr.. The effects vary,
depending upon the density of the suspended material (including clinging
bubbles). To be correct, you should filter or let settle before reading.
3. Always read at the bottom of the meiniscus : | | | |
(the bottom of the u's --->) |\_/| |\_/|<-- tube wall
| | | |
|
hydrometer
4. Always push the hydrometer down slightly past its natural float point and
spin it to eliminate clinging bubbles.
Hope this helps, and pray for me: I'm doing my first all grain batch this
weekend!
Dan Gerth
dgerth@lims1.lanl.gov
------------------------------
Date: 12 Aug 1994 15:28:54 U
From: "Palmer.John" <palmer@ssdgwy.mdc.com>
Subject: Corrosion of 304 Stainless Steel
Thought I would provide more complete information on the chemistry of stainless
steel as it relates to homebrewers. Aiden's post on not using Chlorine Bleach
with stainless steel kegs was not Wrong, but it can be used safely if the
parameters are understood. Here are the parameters.
Corrosion of 300 series Stainless Steel
The 300 series austenitic Stainless Steels commonly used for kegs
and cooking equipment are very acid resistant. The steel receives
its protection from a passive oxide layer that forms on the
surface when exposed to air (oxygen). Because acids are oxidizing,
acids promote this protective layer. The oxide layer is primarily
composed of Chromium oxides with Nickel oxide contributing.
Q: Why doesn't this work for aluminum?
A: The aluminum oxides are porous to do not prevent exposure of
the base metal to the corrosive media. Anodizing is an electro-
chemical process that builds up the surface oxide, making it
thicker and non-porous. Calphilon Cookware is anodized aluminum.
Okay, back to Stainless. The corrosion resistance depends on the
chromium. Austenitic stainless is a super saturated solution of
chromium and nickel in iron. It is actually a very high
temperature phase (arrangement) that has been frozen to preserve
the distribution of elements. Austenitic stainless does not like
heat. It performs well up to 600F, but higher temperatures cause
atom diffusion which causes the properties to change. Compare it
to Ice Cream. If you let Ice Cream get soft, then stick it back in
the freezer, it will stay much the same. But if you let it melt
completely and stick that back in the freezer, you get a frozen
puddle which is no longer what you consider Ice Cream to be.
Welding is a local melting/freezing process whereby atom diffusion
can take place if it is hot enough, long enough. There are
time/temperature curves that describe this, but don't lend
themselves to ascii. Suffice to say that for Type 304 stainless,
five minutes at 600F or above will cause chromium diffusion that
will later cause cracking in service. Exposure to the temperatures
that cause diffusion is termed as being Sensitized. Type 304L
stainless, L meaning less carbon, is more weldable and can spend
almost 20 hours above 600F before becoming Sensitized. Most kegs
are made from 304L to facilitate the welded construction. What
this means to brewers that use high BTU propane burners is that
care must be taken to not overheat the kegs while boiling or this
sensitization will occur over time. Diffusion is cumulative.
Okay, back to corrosion. The corrosion inhibitor is the passive
oxide layer that protects the surface. All corrosion is basically
galvanic. The electrochemical difference between a metal and a
non-metal or two metals in an electrolyte causes electrons to flow
and ions to be created. These ions combine with oxygen or other
elements to create corrosion products.
Now lets say we already have an electrolytic solution containing
ions, bleach water. These chlorides are caustic or alkaline and
cause the protective oxide layer to deteriorate. If a stainless
steel container is completely full of this electrolyte, every
surface is at the same electrical potential and nothing happens.
But what if there were a deep scratch in the wall, or a rubber
gasket against the steel creating a crevice? Well, these areas can
become electrically different from the surrounding area and a
galvanic cell can be created. Inside the crevice, on a microscopic
scale, the chlorine ions can combine with the oxygen, both in the
water and on the steel surface, to form chlorite ions, thus
depleting that local area of oxygen. If the bleach water is still,
no circulation, then that crevice becomes a tiny highly active
site relative to the more passive stainless steel around it and
corrodes. This is known as Crevice Corrosion. The same thing can
happen at the surface if the keg is only half full. In this case,
the steel above the waterline is in air and the passive oxide
layer is stable. Beneath the surface, the oxide layer is at a
different potential and less stable due to the chloride ions. Now
the crevice is represented by the waterline. Stable area above,
less stable but very large area below, crevice corrosion occurs at
the waterline. Usually this type of corrosion will manifest as
pitting or pinholes. The mechanism described is accelerated by
localization so a pit is most often the result.
A third way that chlorides can cause corrosion of stainless is by
concentration. This mode is very similar to the crevice mode
described above. By allowing chlorinated water to evaporate and
dry on a steel surface, those chlorides become concentrated and
change the electrical potential of the surface at that site. The
next time the surface is wetted, corrosion will immediately take
place, creating a shallow pit. The next time the keg is allowed to
dry, that pit will probably be one of the last sites to evaporate,
causing chloride concentration again. At some point in the cycle
life of the keg, that site will become deep enough for crevice
corrosion to take over and the pit will corrode through.
Given the above information, knowing our enemy as it were, we can
develop usage practices to ensure that our precious stainless is
not attacked and pitted by the use of bleach as a sanitizer.
1. Do not allow the stainless steel vessel to sit for extended
periods of time (hours, days) filled with chlorine water.
2. Fill the vessel completely so that all surfaces are at the same
potential.
3. Swirl the water once in a while to eliminate local
concentration/ de-oxidation.
4. After the 20-30 minute soak for sanitizing, rinse the keg with
preboiled water to prevent evaporation concentration and either
dry it completely with a towel (if storing) or fill it with beer.
These simple practices will preclude chlorine induced corrosion.
John Palmer - Metallurgist for International Space Station Alpha
McDonnell Douglas Aerospace, Huntington Beach, CA
------------------------------
End of HOMEBREW Digest #1501, 08/15/94
*************************************
-------
