HOMEBREW Digest #2863 Fri 30 October 1998
FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
Digest Janitor: firstname.lastname@example.org
Many thanks to the Observer & Eccentric Newspapers of
Livonia, Michigan for sponsoring the Homebrew Digest.
Yeast Culturing - Inoculation Loop Problem ("Jeff Hewit")
pump clogging (Wheeler)
Fermentors? (Ken Schroeder)
No-weld Keg or Pot Fittings (Jeff Ehlinger)
bottling beer in wine bottles (Jay Hammond)
Yeast Questions-Sloshing in the Secondary Fermenter ("Michael O. Hanson")
A Study of Fluid Flow Through A Grainbed (John Palmer)
Re: Vectored flow ("Peter J. Calinski")
sterile buffer storage (Dave Whitman)
Barleywine Yeast / Stovetop All-Grain (Ken Schwartz)
IBU Measurement ("A. J. deLange")
Re: mounting a thermometer in a SS pot? ("Bonnell, Doug")
Home malting/Kilning (TOM CLIFTON)
RE: Campfire Porter (correcting for too much chocolate malt) ("Mercer, David")
Too much foam from Corny Keg ("Richard Scott")
storing malt (Alan Edwards)
Beer is our obsession and we're late for therapy!
Send your entries in for Hoppiest Event On Earth yet?
NOTE NEW HOMEBREW ADDRESS: hbd.org
Send articles for __publication_only__ to email@example.com
(Articles are published in the order they are received.)
If your e-mail account is being deleted, please unsubscribe first!!
To SUBSCRIBE or UNSUBSCRIBE send an e-mail message with the word
"subscribe" or "unsubscribe" to firstname.lastname@example.org.
**SUBSCRIBE AND UNSUBSCRIBE REQUESTS MUST BE SENT FROM THE E-MAIL
**ACCOUNT YOU WISH TO HAVE SUBSCRIBED OR UNSUBSCRIBED!!!
IF YOU HAVE SPAM-PROOFED your e-mail address, the autoresponder and
the SUBSCRIBE/UNSUBSCRIBE commands will fail!
For "Cat's Meow" information, send mail to brewery at hbd.org
Homebrew Digest Information on the Web: http://hbd.org
Requests for back issues will be ignored. Back issues are available via:
Anonymous ftp from...
AFS users can find it under...
JANITORS on duty: Pat Babcock and Karl Lutzen (email@example.com)
Date: Wed, 28 Oct 1998 20:26:20 -0500
From: "Jeff Hewit" <jhewit at erols.com>
Subject: Yeast Culturing - Inoculation Loop Problem
I recently decided to move up one more step in my evolution as a brewer, and
started culturing yeast from slants. My first experience went without any
problems, and the beer turned out great. However, I did experience a minor
disaster the second time. First, the wire on the inoculation loop snapped
after some mild mishandling. It broke near the handle, and I managed to
pull out the stub, and insert the remaining wire with the loop into the
handle. I thought I was home free. However, when I heated the wire, it
fell apart - just disintegrated. I don't recall doing anything different
from the first time. I ended up using a paper clip to transfer the yeast
from the slant to the starter. The jury's still out on this technique. I
used a propane torch - the kind plumbers use to solder pipe. Was the heat
from this torch simply too hot for the inoculation loop? Did the first use
somehow make the wire brittle or otherwise degrade it? Are there any tricks
in heating the wire that I need to know? Would an alcohol lamp, like those
sold by the yeast culture suppliers, provide a more friendly flame? Or, if
I just got an inferior inoculation loop, where can I get a good one? I will
appreciate any comments, suggestions, etc.
Return to table of contents
Date: Wed, 28 Oct 1998 21:46:12 -0500
From: Wheeler <wheeler at netaxs.com>
Subject: pump clogging
Randy Pressley asked about the possibility of grain clogging his pump and
there has been mention of using scrubbies and filters to keep grain from
getting into the pump. I have been using a stainless steel screen under my
false bottom ever since I had grain slip under my false bottom and clog the
drain. This arrangement has kept grain and grain particles of any
significant size from getting through to the pump. There hasn't been any
problem with compacting of the grain bed, even when making oatmeal stouts.
The screen under the false bottom is made of two 12 inch dia. SS screens
taken from splatter guards. The drain goes through the center of the false
bottom and pulls the liquid from inside the saucer shaped SS screen filter.
The pictures and some description are at
http://www.netaxs.com/~wheeler/parts.html#falser bottom . Paul Schick asks
about scorching and although I don't heat the mash tun with a jet cooker I
do use a gas burner and have had no problem with scorching.
With this setup I am able to drain at any speed from a trickle to a full
flow. I do batch sparges to save time and being able to do a sparge at full
throttle makes it even faster. I have yet to find any significant
differences between fast or slow rates of flow when draining wort from the
mash tun. Saving time is more important to me than decreased efficiency or
the cost of a little extra grain so I do quick batch sparges.
in Blue Bell, PA
my gas fired RIMS website http://www.netaxs.com/~wheeler
Return to table of contents
Date: Wed, 28 Oct 1998 21:48:04 -0800
From: Ken Schroeder <knj at concentric.net>
Sorry if this has been recently asked (I'm about 3 month's behind on
HBDs): Where can I find ss fermentors in the 20 - 25gal size? Korny keg
type with multiple down tubes would be great. Please email off line to
take less bandwidth: knj at concentric.net
Return to table of contents
Date: Thu, 29 Oct 1998 08:28:16 -0600
From: Jeff Ehlinger <jeffe at davis-lynch.com>
Subject: No-weld Keg or Pot Fittings
Last week I couldn't even spell "engineer" and today I is one!
Greetings from a longtime "lurker". I thought I'd throw my $.02 in on
the equipment side of brewing. People always seem to be asking how to
add thermometer or valve fittings to the side of the keg or brew pot
without welding. This is the best method I've found, which I use on my
two converted kegs.
This fitting will leave a female pipe thread to the outside to make up
various valves, thermometers etc. There are two pieces required to make
this "bulkhead fitting", both of which are SS. The first is a female x
male coupling (adapter). The second is affectionately known as a
Stop-A-Leak Seal, which is a SS pipe nut with a teflon ring molded to
one side. These parts can probably be obtained many places but I do a
lot of "company shopping" at McMaster-Carr and I've listed part numbers
and prices from there. The chart below will (hopefully) cover possible
sizes to use:
Part No. Part No.
Size FemalexMale Cplg. Price Stop-A-Leak Price Req'd Hole
1/4"nptf 48805K36 6.83 5530K42 3.25 5/16"
3/8"nptf 48805K42 9.10 5530K43 3.72 11/16"
1/2"nptf 48805K48 13.76 5530K44 5.56 7/8"
Procedure for Assembly
1. Drill the hole in the side of you pot (keg), not too close to the
bottom as the nut requires some clearance, see nut sizes below. Note,
drilling a 7/8" hole for a 1/2" npt fitting with a hand-drill is
difficult at best and somewhat dangerous, get a friend with a drill
press to help you.
2. File or sand the hole edges smooth.
3. Insert mxf adapter with the male end into the hole and the female end
to the outside of the pot.
4. Make up the Stop-A-Leak Seal to the male end of the adapter with the
teflon ring facing the pot side. Tighten with a socket if you have one,
here are the sizes needed: 1/4"npt - 3/4", 3/8"npt - 7/8", 1/2"npt -
1-1/8", deep sockets are not required. If you don't have a socket to
fit, use a crescent wrench, the nut doesn't have to be super tight.
5. You could reverse the direction of the fitting to have the male end
sticking out, it still works. Fittings screwed onto the male end of the
adapter will still seal even with the nut on, just use two or three
rounds of teflon tape on the male end.
6. For small pots (<13"dia.) you may want to beat a flat spot before you
drill the hole, so the nut (stop-a-leak) will seal better.
I'm sure I've forgotten something so feel free to private email
questions. I've checked the parts numbers but VERIFY what you're
ordering from McMaster. Usual disclaimers apply regarding holes drilled
in hands etc.
Sorry for the long post, I now yield to the "Clinitesters", "FWHers" and
Return to table of contents
Date: Thu, 29 Oct 1998 09:35:00 -0500 (EST)
From: Jay Hammond <jhammond at bryant.edu>
Subject: bottling beer in wine bottles
I wonder if anyone has advise on bottling beer in wine bottles. I
have a batch of Kreik style beer ready to bottle and wonder if simply
filling and corking the bottles will be good enough. Do you think that the
type of wire stopper used on champagne bottles is required to prevent the
corks from blowing out due to fermentation from bottle conditioning. Any
ideas on this type of bottling would be helpful.
Return to table of contents
Date: Thu, 29 Oct 1998 08:34:48 -0800
From: "Michael O. Hanson" <mhanson at winternet.com>
Subject: Yeast Questions-Sloshing in the Secondary Fermenter
Hello Fellow Brewers,
I am writing with some questions about liquid yeast. Homebrewers seem to
prefer liquid yeast. This does not seem to be the case with home
As a brewer, I have used both dry and liquid yeast. Dry yeast seems to
work well and is easier to work with. It may be that some kinds of liquid
yeast are not available as dry yeast or don't have dry counterparts.
Liquid yeast is more difficult to work with because a starter is required
or at least strongly advisable to reduce lag times. Using a starter with
dry yeast will also reduce lag times.
There seem to have been some legitimate historical concerns with available
dry yeast. What is the current state of affairs? I know several
Microbiologists who inform me that dry yeast can be as free of
contamination or less contaminated than liquid yeast because of the method
of preservation. Dry yeast also seems to last longer than liquid yeast.
Wyeast cultures have a shelf life of 30 days according to some authors.
I've successfully used dry yeast that I know to be over a year old.
What advantages are there in using liquid yeast? Have strains of dry yeast
become available that match the characteristics of liquid yeast in terms of
attenuation, flocculation, and flavor profiles? If not, why not? If such
strains are available, where could I find information about them?
I would appreciate any information you could give me on this subject.
Private e-mail is fine.
Recently, a question was raised about sloshing in a secondary fermenter to
rouse the yeast. This could be done if the headspace is filled with CO2
and the rousing was gentle enough to prevent oxygen getting into the beer.
There would seem to be an increased risk of oxidation if the beer is
sloshed in a secondary fermenter. I would suggest that the brewer make
sure the target gravity has not been reached before rousing the yeast. Dry
yeast can ferment very rapidly. I have often seen primary fermentations
using dry yeast reach target gravity in the time indicated.
A possible alternative would be to form an airtight closure and then rouse
the yeast. I'm not sure how to go about this since I don't know the
specific design of the carboy ad airlock. An undrilled stopper might form
a sufficiently tight closure. The airlock would need to be replaced after
the yeast had been roused to allow CO2 to be vented off if fermentation
Thanks in Advance,
Return to table of contents
Date: Thu, 29 Oct 1998 09:45:23 -0800
From: John Palmer <jjpalmer at gte.net>
Subject: A Study of Fluid Flow Through A Grainbed
A Study of Fluid Flow Through A Grainbed Using a Manifold-type Lautering
Note: To the best of my knowledge, the following represents original
work and should be considered intellectual property.
For several years now, the question of how well a manifold lautering
system works has been nagging at me. In 1995, Paul Prozinski and I
wrote an article for BT called, "Fluid Dynamics - A Simple Key to the
Mastery of Efficient Lautering". It was based on fluid flow as
discussed in basic civil engineering and concluded that more coverage
area was better to discourage "coning" of the flow and "dead zones" out
at the corners. It is available in Volume 6, No. 5 of Brewing
Techniques (1995). It corroborated earlier (independent) discussions
posted by Al Korzonas to the HBD.
In the 1995 Special Issue of Zymurgy (Great Grains), Al Korzonas had an
article in which he and Steve Hamburg did a huge mash and then lautered
equal portions in different types of lauter tuns.. The systems were:
rectangular cooler and manifold, round cooler and Phil's Phalse Bottom,
Pico Brewing System with copper slotted screen, Easymasher(tm) and a
mesh-bottomed bag in a spigoted bucket (Miller-type system). The first
three were adjusted to take 7 gallons of runnings in 1 hour. The last
(Miller) could not be made to run so fast. It took 2 hours, wide open.
The biggest variation was in recirc-time to get a clear wort. The
EasyMasher was the shortest, followed by the others, with the Pico last,
probably due to the large amount (~ gallon) of underlet/foundation
water, so it was not surprising. (This paragraph courtesy of Al K.)
As I was reviewing the technical edits for the Lautering chapter of my
(still) forthcoming book, I turned a critical eye on my discussion of
flow and decided that I needed more solid information rather than
logical arm-waving. So, I contacted Guy Gregory, a Hydrogeologist at
Spokane, and we set about trying to model how fluid flow in a lauter tun
Guy and I initially used Darcy's Law which is from fluid flow/civil
engineering/hydrogeology science. Darcy's Law as modified by Wesseling
(1973) states that
V = 4KH^2/L^2 and V = Q/A
V = drain discharge rate per unit surface area in cm/sec,
K= hydraulic conductivity of the grain = 2.5 x 10-2 cm/sec,
H= Desired level of saturated grain at the margin of the radius of
influence above the bucket bottom, in cm.
L= 2x the radius of influence of the drain, in cm. (the unknown).
Q = Optimum discharge rate
A = Area of the tun
The specific discharge, V, is equal to Q/A.
Several years ago, Dr. Narziss of Weihenstephan University, wrote a
paper in which he asserted that the ideal initial lautering rate was.18
gallons per min-ft^2. Narziss had directed that this number N be
multiplied by the area of the lauter tun to determine a volume rate for
If you convert that number into terms of cm and sec then N is
approximately .0122 cm/s.
Well, if we say:
V = 4KHsq/Lsq
and V = Q/A and Q = NA, then voila, A drops out and we have V = N
So, we get N = 4KHsq/Lsq
Or, rearranging to solve for the drain spacing L, you get
L^2 = 4KH^2/N
Inserting appropriate values, rounding off to significant digits, and
converting the units to inches instead of centimeters gives:
L^2 = 8 H^2 or R^2 = 2 L^2 where R is the effective radius of drain,
and equals L/2. The behavior of flow depends on the depth of the liquid
(H), not the depth of the media. In groundwater situations, the media
is usually higher than the water level, whereas for lautering, the water
level is always above the grainbed.
Using this equation, our model showed that for all but the shallowest
grainbeds, a single pipe running down the center of a picnic cooler
should be more than adequate for efficient drainage.
But! Drainage is not the be-all and end-all of lautering. The
experiments did not support this model.
To observe how the fluid flowed through a grainbed, I used a clear
plastic filing box of dimensions 9W x 12L x 10H to conduct experimental
lauters in, varying different variables- Depth, Flow Rate, and Drain
Spacing. I used ground up corncobs (burnishing media) for the majority
of the tests. They are of fairly uniform size (.03 inch) and Guy checked
their hydraulic conductivity and it came out close enough to a barley
mash. The corncobs were great for creating a reproducible testbed that
could be conducted at room temperature without needing to be mashed
first. Redundant experiments using a real spent mash showed identical
results. In all tests, the drain(s) consisted of half inch hard copper
tubing cut with hacksaw slots, connected via a bulkhead fitting to vinyl
hose and metered by a ball valve. A standard flow rate for the tests
was 1 quart a minute, unless flow rate was the variable. All trials
were performed using continuous sparging, maintaining a constant depth.
Here is a top view of the manifold layouts:
Initial tests were done by injecting food coloring directly into the
mash near the walls and observing the flow paths to the drain. The tests
showed a parabolic path to the drain, with faster flow of dye in regions
directly above and immediately adjacent to the drain versus dye placed
out near the walls several inches away. The results disagreed with our
initial drainage model and it was difficult to glean much information
from this method. It caused a re-examination of the test procedure.
The next set of experiments involved dying the whole water layer above
the grainbed, opening the drain, and watching how the dye flowed into
the grainbed. These results were much more telling of the way that
sparging actually worked. After all, during the sparge, we are
attempting to move fluid through all regions of grainbed to the drain
and thereby achieve the best extraction. These experiments showed that
there was a big difference in the flow rate, and thus the volume of
water, that moved through the bed to the drain from areas above and
adjacent to the drain compared to regions far away at the corners.
Here are a series of pictures showing how the dye moves through the
grainbed toward a single drain:
1. This shows the dye above the grainbed prior to opening the drain (in
2. This shows flow toward a single drain after about 2 minutes of flow.
Note the coning of the dye front. A view from the side better shows the
lack of dye to the bottom corner.
3. After 10 minutes, the dye has reached to within a half inch of the
floor, but if you look closely, you can see that the middle area above
the drain is starting to rinse clean already. Further observation
showed this more clearly, but I ran out of film. As the sparging
progressed, the far corners remained green while the center was rinsed
Here are two pictures showing identical behavior in a spent mash with a
fair amount of sugar left. (1.015). The temperature of the mash was
about 120F during the test, but I was lautering with 90F water, so it
was cooling further.
Other trials where flow rate or fluid depth were varied showed no
significant difference in behavior of the dye front. Flow rate was
tested at 2.2 quarts per minute and 0.5 quart/minute. The dye front
moved faster or slower, but was the same shape. Varying the depth of
the water, ie. the head height, seemed to change the angle of the cone a
bit, but it was hard to tell.
Dual Drains and Spacing
The next round of experiments used two pipes connected to the bulkhead
fitting with a Tee. The spacing between the two pipes could be varied.
Trials were conducted with spacings of L = 4 and L = 6 inches. These
spacings were chosen because the spacing of 6 inches in the 12 inch wide
box results in a distance of L/2 between the pipe and the wall, while L
= 4 equates to a distance L to the wall. We have suggested L/2 spacing
in the past to minimize the affect of preferential flow down the walls
of the tun, bypassing the grainbed. (However, due to the actual width
of the tubes in this set-up, the distance to the wall was actually 2.5
inch instead of 3 inches.) The two spacings provided a good difference
in predicted behavior.
These trials had the following results (black circles are used to
indicate drain positions):
1. With the pipe spacing at L=6, the dye front after 2 minutes of flow
looked like this:
2. After ten minutes of flow, the dye front had reached the bottom, and
the corners were already being rinsed. As mentioned, the spacing of the
pipes to the walls is actually less than L/2. The residual color in the
back corner of the tun is due to the position of the drain pipe there.
Due to the length of the Tee fitting and the elbow fitting, the slotted
pipe sits about 2 inches off from the back wall, whereas in front, it
comes to within a half inch of the wall.
The next trial was with L = 4, and it looked like this:
1. Before Flow. (some green is left over from the previous trial)
2. After 2 minutes.
3. After 10 minutes. Note some lack of flow at the corners.
Time For A New Model
Obviously, this data did not support the R^2 = 2H^2 model, or vice
versa. I started thinking about what this data meant; specifically how
to account for the differences in flow rate between different regions.
I realized that the difference in flow velocity for two distances from
the drain pipe, r1 and r2, must differ as a function of r^2, rather than
just r (linearly). I bounced this hypothesis off Guy, and he agreed
that, at the same depth or Head, that v1/v2 = r1^2/r2^2.
Eureka! So, the flow velocity potential at any point in the grainbed is
a function of the Head, divided by the distance from the drain
(squared). V~ H/r^2 This brought to mind Ohm^Òs Law, which states that
the Potential (V) divided by the Resistance (R ) in this case the
grainbed and all subsequent plumbing, equals the Current (I) which in
this case can be considered as the final flow velocity. It became
apparent to me that by plotting the potential for flow across the
dimensions of the lauter tun, I could model how the flow reacted to the
position of the drain.
The equation looks like this V = 100H/(x^2+y^2)
The scaler of 100 was used to make V greater than 1 in all cases.
With this idea in hand, I generated an Excel spreadsheet such that the
cells each represented a actual square inch and calculated V for that
cell's position relative to the drain. The drain was located at the
bottom of this "tun", in the middle. The numbers immediately gave an
indication of the convergence of the flow I had observed in the trials.
I shaded similar values to help indicate this, and the result is below.
Two drains at L=6 looked like this:
I made up several spreadsheets for single and double drains and sent
them to Guy. He agreed with the model, saying it looked like I had
succeeded in solving 2D Steady State Flow without resorting to Finite
Difference Analysis techniques. He was able to verify it using 3D Flow
Modeling software that they have for modeling watersheds. In addition,
he was able to take the spreadsheet values and generate equipotential
flow gradient lines. These equipotential graphs match the observed flow
patterns almost exactly. The graphs are shown below with gray arrows to
show how the flow is vectored perpendicular to the gradient lines to
approach the drains.
Three drains spaced at 2, 6 and 10 in a 12 inch wide tun work even
better than two drains. This spreadsheet is not to scale, nor is it
shaded but you can look at the numbers and get the idea.
The spreadsheets show that with the increase in drains, you flatten the
equipotential lines across the tun. Increased depth helps because it
means that a greater percentage of the grain is up in the lesser
gradient levels where the equipotential lines are flatter. This model is
most applicable to rectangular picnic coolers since they allow a uniform
Custom Designing Your Manifolds
What I hope to do soon is to be able to have a Java applet on my web
page which will take the tun dimensions, depth and the drain locations
and generate a graph of the equipotential curves. One of the
programmers here at work is looking into it.
Further Experimentation Needed
As with any theory and model, there is always more work to be done. As
noted above - this model only looks at flow from a Potential aspect. It
assumes that the media (grainbed) is homogenous i.e., that the
resistance to flow in all cases is the same. In a real mash, this is
obviously not the case. Noonan shows in Brewing Lager Beers that a
cross-section of the mash has different particle sizes from top to
bottom. In fact, during the trial using a spent mash, I had almost a
half inch of that annoying topdough on top of the grainbed. It really
slowed down the initial flow, even though the shape of the dye front
matched what was observed using corncobs.
Wort, by virtue of being more dense than water, and more viscous, will
tend to underperform predictions based on water (see the Bernoulli
equation) but basically all things being equal (head, temperature,
etc.), a thicker denser fluid (syrup) flows through a small pore more
slowly than a thinner, lighter one (water). With this in mind, you can
hypothesize that as the sparge progresses, the difference in flow rate
between the area over the drain versus the areas away from the drain
will actually increase due to the increasing difference in wort
viscosity and density between the two regions, which should affect
extraction. More data is needed in this area.
I think that one aspect of lauter tuns that allows this model to work is
that the greatest constraint to flow is at the valve where we meter the
flow rate, not within the grainbed. This difference provides for any
inhomogeneities in the grainbed to be insignificant compared to
resistance downstream. It also allows for all segments of the manifold
to draw equally from the bed.
This brings up a question I have had: How does the flow out of a false
bottom into the open area beneath the false bottom, react to the single
outlet tube? In this case, the flow is going from the resistive flow of
the grainbed, to the unrestricted flow of the underlet area, to the
constrained flow of the outlet pipe. Based on my work to date, I think
that the flow from underneath the false bottom to the outlet point is
affected by the same r^2 (maybe even r^3) of the manifold model. Or,
perhaps there is enough mixing of the wort under the false bottom that
any differences in flow from far away portions of the false bottom is
not significant. Anyone have a transparent false bottom set-up?
Return to table of contents
Date: Thu, 29 Oct 1998 09:20:48 -0500
From: "Peter J. Calinski" <PCalinski at iname.com>
Subject: Re: Vectored flow
In HBD 2862
Dave Ludwig wrote:
[ lots of great stuff about gradients etc.]
Boy I hope this makes sense when I read it in the morning. Cheers!
It did to me. So I ask:
Can I make a good, effective manifold as follows?
Home Depot sells copper tubing in flat coils, i.e.. not like springs but
flat, spiraled from the center out. Could I buy a 5 foot length of say 1/4
inch ID tubing, crimp or otherwise seal the end at the center of the coil
and cut radial slits partially through the tube with a hacksaw in a spoke
like fashion? By radial I mean lay the whole thing flat and cut across all
the coils at the same time. Maybe space the slits so they are an inch or
so apart at the outer rim.
I believe this would give me about 4 turns so the spacing between coils
would be 1.5 inches or so. (I haven't worked this out in detail, I am just
looking at the concept now.)
To use it, from what I have read here, it should be placed at the bottom of
the mash tun with the slits facing down.
What does the collective wisdom think?
Is the concept good?
Is the spacing good?
Would a different ID tubing be preferable?
What are the criteria I am trying to meet? Flow rate, etc.
Would an identical assembly serve as a way to feed the sparge water into
Thanks in advance
East Amherst NY
Near Buffalo NY
0 Degrees 30.21 Min North, 4 Degrees 05.11 Min. East of Jeff Renner
Return to table of contents
Date: Thu, 29 Oct 1998 09:57:22 -0500
From: Dave Whitman <dwhitman at rohmhaas.com>
Subject: sterile buffer storage
In HBD#2862, Jim Liddil asks questions and raises objections about my
experiment on buffering the water used to store yeast.
>What was the cell number and viabilty based on methylene blue at the time the
>cells wer placed into the vials? And what was the exact volume of fluid in
The volume of liquid in the vials was 2 +/- 0.1 ml. Each vial got two
loopfuls of yeast solids harvested off actively growing slants. While no
attempt was made to rigorously control the cell count, I estimate that
differences in added yeast solids were about +/- 20%. It's not obvious to
me what the initial or final cell counts have to do with anything, unless
dead cells magically disappear. What matters is which method of storage
gives a higher percentage of viable cells after storage.
While I don't know what viability was at T=0, it seems unlikely that it was
<95% since the buffered samples were higher than that after 3 months storage.
>You n value is small and you have no idea what the cell number in the
>to start with. Did you take repeated samples from each vial and repeat the
As mentioned in the original post, viability was estimated with at least
two microscope slides prepared from each vial, with multiple regions
counted on each slide. I continued to count fresh regions and slides until
I had recorded 800-1200 cells for each vial. The number of
semi-independent determinations for each strain/treatment were:
1968 DI water n=8
1968 buffer n=7
3068 DI water n=6
3068 buffer n=6
As shown by t-test, given the large size of the effect, the experiment is
more than adequate to distinguish between the two treatments. While I wish
I had enough vials to block determinate error in preparing the samples, I
did the best I could with the yeast solids I had on hand 3 months ago.
ANOVA across the yeast strains showed a significant treatment effect with
n=4 totally independent samples.
>800 cells may be a statistically small value for the actual number
>of cells in the vial.
While I followed the published procedure's guideline on number of cells to
count, Jim's comment is a red herring. The number of cells you need to
count is related to the inherant uncertainty of the measurement technique
and how small of an effect you want to be able to detect. It has nothing
to do with how many cells are in the vial.
Jim goes on to take cheap shots at my statistical treatment and method of
determining viability, after I took pains to point out both the value AND
limitations of the experiment in the original post.
I'm left with the impression that Jim has been criticized for lack of rigor
in the past, and has been saving up some bile for the first opportunity he
got to dump it on someone. Would I have received this criticism if I had
posted "Hey, I put some salt into my yeast samples and I think they stored
better"? Petty crap like this certainly makes me less interested in
sharing results with the collective in the future.
Dave Whitman dwhitman at rohmhaas.com
"Opinions expressed are those of the author, and not Rohm and Haas Company"
Return to table of contents
Date: Thu, 29 Oct 1998 08:21:01 -0700
From: Ken Schwartz <kenbob at elp.rr.com>
Subject: Barleywine Yeast / Stovetop All-Grain
Adam Holmes asks about attenuative yeasts for barleywines.
I (and others who have posted here) had good success with Danstar
Nottingham dry yeast. In my case, I had made an amber ale using
Nottingham for Christmas give-away, and racked the BW wort onto that
yeast cake. However, pitching from the foil should work well too and
you have the added advantage of being able to add a LOT of yeast (a good
plan for high-gravity worts) by using two or three packages (which will
still be cheaper than liquid yeast...). My BW went from 1.092 to 1.017
in about a week on its own.
Adam also mentioned that he is brewing all-grain on a "crappy stove" by
straddling the seven gallons over two burners. For anyone interested in
all-grain but lacking space or equipment (like large vessels and good
burners!), consider no-sparge or batch-sparge brewing! You can produce
a smaller volume of higher-gravity wort which you can top off in the
fermenter as you may already be doing with extract batches. Sure, it'll
cost you some efficiency, but so what -- it'll still be cheaper than
extract and you'll have all the benefits of all-grain recipe formulation
at your command.
No-Sparge brewing is done by mashing an all-grain wort as usual, but
after recirculation, simply drain the wort into the brew kettle and
let'er rip. No sparging involved (thus the name). Batch-sparging adds
one more step, that being adding another charge of hot water after the
initial wort is drained, stir, allow to rest a few minutes, and drain
again. Has the advantage of retrieving much of the wort left behind in
In the brewing literature, it's usually been recommended to formulate
no-sparge recipes by inreasing the grain bill by 1/3. I've worked up a
mathematical analysis of both no-sparge and batch-sparge brewing which
shows that in order to gain consistency and predictability in the
formulation, a few things must be taken into account, and you may end up
with significantly more than 33% depending on those factors. Watch for
this addition to my webpage soon.
El Paso, TX
kenbob at elp.rr.com
Return to table of contents
Date: Thu, 29 Oct 1998 11:11:48 -0500
From: "A. J. deLange" <ajdel at mindspring.com>
Subject: IBU Measurement
In the discussion of IBUs let's remember that even a measured bitterness
value does not tell the whole bitterness story. The ASBC has 4 methods
for measuring bitterness (one of which is archived i.e. not currently
used). Method A uses solvent extraction (method D is an automated
version of Method A) and spectrophotometric absorbtion at a single
wavelength. Method C uses solid phase extraction and HPLC to estimate
iso-alpha acids. Method A is sensitive to certain preservatives used in
commercial brewing and Method C to the age of the hops used in brewing
the beer. The two methods give results which are "practically identical"
(quoting from the ASBC procedure) when fresh hops are used and,
presumably, none of the interfering preservatives are present. Quoting
further, ".. the IAAs [iso alpha acids measured by Method C] of beer
brewed with old or poorly stored hops and with certain special hop
extracts, can be significantly lower than the BU [Bitterness Units
measured by methods A and D] figure. Thus, for homebrewed beer with the
possibility, make that probability, of old or improperly stored hops, it
is clear that Method A is preferred (not that any of us could afford the
HPLC anyway) and we need to know, when a testing service is used,
whether Method A/D or Method C is used.
The ASBC Subcommittee on Determination of Isohumulone in Beer has
determined that Method A "expresses the bitterness of beer
satisfactorily" and the EBC also found that their similar method "..best
expresses the true bitter flavor of beer." I interpret these phrases to
mean that neither ASBC Method A nor the EBC method does better than give
an relative measure of bitterness for beers brewed the same way. My IPA
and Old Dominion's Hop Pocket both measure 50 IBU's. The bitter
qualities of these two beers are, to my way of thinking at least,
entrirely different. Throw in a Pils nobly hopped to that same level and
you are in a dimension of bitterness mutually orthogonal to the
bitterness of the first two beers I mentioned. Asked to rank these in
bitterness I'd say the Pils was much less bitter than the ales and I'm
not sure how I'd place the ales relative to one another.
Thus it seems to me that the value of IBU measurement, is in common with
many of the ASBC and EBC prescribed measurements, of most value to large
scale producers who use them to insure consistency of product. Don't
forget that these establishments also do elaborate taste panel testing.
Also, don't get the impression I don't value measured bitterness. It's
fascinating to compare measured bitterness data on a pair of beers with
one's taste impressions of those same beers.
Return to table of contents
Date: Thu, 29 Oct 1998 09:22:23 -0700
From: "Bonnell, Doug" <DBonnell at BreeceHill.com>
Subject: Re: mounting a thermometer in a SS pot?
On Wed, 28 Oct 1998 Badger Roullett wrote:
> Greetings, from that wacky medieval guy...
> ok, so this is a modern day question, but i do that to...
> I have seen posts/webpages from people who have thermoters mounted in
> wall of their pots. How can i do that, and without welding.... can i
> so i can remove my thermometer too? for using on other things..
Most everyone is using a bimetal thermometer with a 3 inch dial made by
Trend or Ashcroft. They have a 1/2 inch male pipe thread ( MPT ) on the
One source on the web is: http://www.mcmaster.com/. Search for bimetal
thermometers, page 363 of their catalog has the less expensive ones.
I've installed mine by drilling a hole in the pot wall just large enough
the 1/2 inch MPT fitting of the thermometer. I use a 1/2 inch locknut
electrical conduit. These are very inexpensive ( <30 cents ) and are
thin for a nut of this diameter. The nut goes on the MPT fitting first
threaded back toward the dial of the thermometer as far as is will go.
Next comes a fiber washer, helps to provide scratch protection between
and the pot wall, plus allows tensioning to reduce leakage from thermal
Insert the thermometer into the hole from the outside of the pot. From
place an O-ring ( 7/8 inch ID by 1/8 inch thick ) over the threads and
"roll" it up
to the inner pot wall.
You now have several choices how to secure the thermometer on the
You will want to use a "food grade" metal, copper, brass or stainless
These metal parts consist of a washer to go between the O-ring and a
nut to tighten the whole assembly. BTW, screw the nut on hand tight from
inside and then use pliers to tighten the nut outside of the pot. This
tearing the O-ring.
I haven't found any washers with the proper inside diameter. Copper and
washers are easy to enlarge, but stainless steel washers can also be
I drilled out a 5/8 inch ID stainless "fender" washer. I used a
stainless "half coupling"
as a nut since the coupling cost less than $3, while a "real" SS nut
$6. A really cheap nut can be had by cutting the hex shaped section off
of a copper
plumbing fitting, should be less than $1.
Be aware that the Trend thermometers sometimes have the last 3 or 4
threads on the
MPT as a slightly larger diameter. This "locks" the thermometer into a
full or half coupling, but makes it impossible to get a lock nut all the
towards the dial. I had one such thermometer, so I put it's probe into a
( hand tight ) and filed the offending threads as the thermometer spun.
me to get the nut all the way back. My Ashcroft thermometers didn't have
So much for hardware, now.... back to software! :-)
Return to table of contents
Date: Thu, 29 Oct 1998 16:20:56
From: TOM CLIFTON <t_clifton at usa.net>
Subject: Home malting/Kilning
I made a batch of "home grown malt" some time ago, and had pretty good
success using a food dehydrator to dry and "kiln" the malt. I cut
fiberglass window screen into large circles so the malt wouldn't fall
through the cracks. The malt was extremely pale as the temperature
never seemed to get over 115 to 120 degrees.
The only problem I had was that I couldn't come up with malting barley
and used a high protein feed barley. The result was poor germination,
and the resulting malt was full of unmalted barley and irregular
modification of the grains that did sprout.
St. Louis, Mo
Get free e-mail and a permanent address at http://www.netaddress.com/?N=1
Return to table of contents
Date: Thu, 29 Oct 1998 08:53:06 -0800
From: "Mercer, David" <dmercer at path.org>
Subject: RE: Campfire Porter (correcting for too much chocolate malt)
James Spies asks about 'fixing' a porter brewed with the following grain
5 lbs. Marris Otter Pale
5 lbs. Weyermann's Munich
1 lb. 90 lov. crystal
~14 oz. Chocolate malt
~3 oz. Black Patent malt
My experience with chocolate malt is a little goes a long way - I almost
never use more than 4 oz in a recipe, and even half that (i.e. 2 oz out
of, say, 192 oz, or roughly 1% of the grain bill) will be noticeable. I
think that's your culprit here, more than the black patent or crystal.
I've also noticed that the burnt edge from the chocolate, which I like
in small doses, mellows over time. After as short as 3-4 months it is
pretty much gone. You've got a lot of chocolate there, but my advice is,
give it time. If you bottle and store the beer carefully, by Spring it
should have lost a lot of it's campfire edge. But it could take longer.
I have some stout that I brewed three years ago where I WAY overdid the
roasted barley (I'm embarrassed to say by how much.) It took a year for
that stout to be drinkable. Now it tastes wonderful: complex, malty,
mellow and a little sweet. (But it still looks like burnt motor oil when
I pour it.)
The moral is, time corrects a lot of problems like this if you're
patient enough to let it. At least, it's come to my rescue more than
Dave in Seattle
Return to table of contents
Date: Thu, 29 Oct 1998 11:30:12 -0600
From: "Richard Scott" <rscott57 at flash.net>
Subject: Too much foam from Corny Keg
Chuck Cubbler wrote:
>However, after consuming a little more than half of the keg, I begin to
>experience very foamy pours.......Guy at the homebrew supply said to
>turn up the pressure, that the CO2 is coming out of solution..... He
>suggested that I turn up the pressure, so I did, from about 12psi to
>about 18 psi. What I get is a faster pour, still mostly foam.
>From the Texas school of trial & error, I too experimented with
fixing this problem. My fix: first was to make certain that I had
properly carbonated the beer after racking (refer to Zymurgy, Summer
1995). Second, as the keg continues to drain, I backed off the CO2 psi
by a bit. Too much made the beer go flat. Again, trial & error gave
me the 10 psi solution that I use today at one-half keg or less. Another
impact for me was the time it took to drink the keg. Now I have an
excuse to hold more parties & finish the kegs quickly. :-)
I keep CO2 bottle & keg in the beer 'frig at all times, always hooked up
and picnic tap ready to dispense. My guess is that the 40 degreeF
keg beer can continue to gain carbonation if the CO2 pressure is high.
Further, without backing off the CO2 pressure, very highly carbonated
beer is being spewed out at a high pressure.
No doubt that the right hops & other ingredients greatly impact
the good head, but I was concerned with the mechanical aspects
of good kegging.
Return to table of contents
Date: Thu, 29 Oct 1998 10:09:54 -0800 (PST)
From: Alan Edwards <ale at cisco.com>
Subject: storing malt
I've finally decided to buy a mill and would like to get some sacks of
malt to go with it. ;-)
What are the finer points of storing 50 pounds of malt? Can you just
put it in a RubberMaid container and forget about it? Or do you need to
worry about the humidity or temperature? What are the natural enemies
of malt and how do you keep them out?
-Alan in Fremont, CA
Return to table of contents
HTML-ized on 10/30/98, by HBD2HTML version 1.2 by K.F.L.
webmaster at hbd.org, KFL, 10/9/96