Month: December 2009

Calculating Mash Water Volume ::: Brew365: “The amount of water absorbed by the grain during the mash can vary from system to system due to crushing methods, stirring practices, etc. Ray Daniels provides a constant of roughly 0.2 gallons of water absorbed per pound of grain. Denny Conn, in his great article on Cheap and Easy Batch Sparging provides an estimate of 0.1 gallons of water absorbed per pound based on his brewing system. As you can see, these vary greatly and can make a big difference in the total water added. The best thing to do is for you to note the volume for your particular system over several brew sessions, and keep a table of pounds of grain to water absorbed for your system.”

HOMEBREW Digest #1792 Thu 27 July 1995:

Date: 26 Jul 1995 07:32:18 U
From: “Palmer.John” <palmer at ssdgwy.mdc.com>
Subject: Scientific Mashing Breakthru!

Well, Not really.
But I did find out something that should be very helpful to many of you.

I have been asking a few eminent homebrewers how much grain can be mashed in afixed volume Cooler ex. a 5 gallon Gott. The answers have been helpful, but anecdotal, i.e. “I did X lbs for this batch”.

So, last night on the way home from work, I had a brainstorm. Why not mash 1 lb in 1 quart and see what the volume is?!

Well, I did. I carefully weighed 1 lb of Great Western 2 Row malt, crushed it in my Maltmill and added it to 1 quart of 120F water. I let this sit for about 5 minutes. Since I only have a 1 quart pyrex measuring cup, I poured 24 oz of mash into the measuring cup and discarded it. I then poured in the remainder and measured it. It came to about 18 oz.

It occured to me that because the first measurement was more fluid, and the second pretty stiff, I might be experiencing compaction, and not getting a good measurement. So, I measured out 2 more cups of hot water (16oz) and added it to the 2nd measure of mash in the quart measuring cup. If I had been paying better attention, I would have only added 1 cup. The liquid level rose to just over the 32 oz mark.

Comparing the two measurements, I determined that the addition of 16 oz of water to the 18oz looked to be a change in volume of 16 oz, meaning that I had negligible compaction.

So! We now have a brewing constant for figuring how much grain can be mashed in a fixed volume. 1 Pound of 2 Row Malt mixed with 1 Quart of Water produces a volume of 42 fluid ounces. If you are figuring a 1.5 quart per pound mash, then add in the additional half quart per pound as my measurements show that 1 quart per pound is already a saturated condition.

In summary, 10 lbs of Malt at 1.5 qt/lb would fill just over 4.5 gallons, which would be do-able in a 5 gallon cooler. This would yield a 1.060 beer.

John J. Palmer – Metallurgist for MDA-SSD M&P
johnj at primenet.com Huntington Beach, California
Palmer House Brewery and Smithy – www.primenet.com/~johnj/

HOMEBREW Digest #1793 Fri 28 July 1995:

Date: Thu, 27 Jul 1995 12:14:54 -0700 (PDT)
From: Dan Sherman <dsherman at sdcc3.ucsd.edu>
Subject: Re: Scientific Mashing Breakthru!

John Palmer <palmer at ssdgwy.mdc.com> wrote:

So! We now have a brewing constant for figuring how much grain can be mashed in a fixed volume. 1 Pound of 2 Row Malt mixed with 1 Quart of Water produces a volume of 42 fluid ounces.

And, since 1 quart of water is 32 fl. oz., we can conclude that 1 pound of 2 row malt displaces about 10 fl. oz.

So, assuming you use at least 1 qt/lb:

mash volume (in ounces) = (total quarts of water)*32 + (lbs of malt)*10
or
mash vol. (gallons) = (total quarts of water)*0.25 + (lbs of malt)*0.08

In summary, 10 lbs of Malt at 1.5 qt/lb would fill just over 4.5 gallons

mash vol. (gal.) = (15)*0.25 + (10)*.08 = 4.55 gal.

Thanks, John. Great job!!

Cheers!

Dan Sherman
San Diego, CA
dsherman at ucsd.edu

Beer’s Law – Dan A. Morey: “It has been well documented that beer color is not a linear scale. So why try to relate Malt Color Units to an estimated SRM by a linear equation? I propose a power equation would better approximate the color phenomenon.

What I did was: Assume MCU = SRM from 0 to 10.5, Daniel’s equation holds in the range of 10.5 < MCU < 37, and Mosher's formula holds for MCU < 37. Then I plotted In (MCU) vs. In (SRM) and performed linear regression. This exercise resulted in a R^2 value of 0.97 (This is better than my linear fit with force zero intercept on the MCU vs. SRM graph – R^2 0.96). My resulting equation is:

SRM = 1.4922 [(MCU) ^ 0.6859] – for values of SRM < 50

Now there is a single equation that can be used to estimate the final color of beer.”

Hop Aroma and Flavor: “It is well documented how bitterness is obtained in the finished product via the isomerization of alpha acids, but investigations into the chemistry and utilization of hop essential oils for beer flavor and aroma have, in general, failed to elucidate the complex processes involved. In this article I begin with some background on hops and their use in brewing beer, and then narrow the focus to examine the essential oil of hops. I first discuss the chemistry and composition of hop oil in hops and beer, and then quickly turn to the practical by discussing how to evaluate and analyze hops for the aromatic quality of hop essential oil. I conclude with some methods to obtain and protect hop flavor and aroma in your finished beer, which I think is the most important take home message of all.”

First Wort Hopping – BrewBoard: “The difference, to me, is that [first wort hopping] adds hops flavor and smooth bitterness and mash hopping basically does nothing but waste hops.”

First Wort Hopping Summary: “In the latter part of 1995, Dr. George Fix posted to the Home Brew Digest about a process he had recently come across described in the brewing literature. Since then much interest in the procedure has arisen. The process is called First Wort Hopping (FWH), and it refers to the practice of adding hops to the brew kettle, into which sparged runnings are collected, at the beginning of sparging. The idea is that the hops soak in the collecting wort (which usually runs out of the lauter tun at temperatures ranging from 60 to 70C depending on one’s setup) for the duration of the sparge, and the volatile hop constituents undergo very complicated reactions, producing a complexity of hop bitterness and aroma that is obtainable no other way.”

Preboil Hop Addition – BrewBoard: “Boiling wort is devoid of oxygen as gas solubility in liquids decreases with increasing temperature, but oxidation reactions of oils take place at higher temperatures, making the mash runoff an ideal place to oxidize hop oil compounds. This oxidation makes the compounds more stable, lowering their boiling point (less volatile) while also changing their flavor slightly. The exact reactions I’m sure are pretty complicated. The end result though, is usually damn tasty.”

…and…

Preboil Hop Addition – BrewBoard: “Just to add to this, fats, oils, lipids are usually completely hydrophobic molecules or like membrane lipids are amphipathic (have both a hydrophobic and hydrophilic group) The oxidation of these oils actually makes them soluble and thus adding to the long-term stability of these flavour compounds in beer.”

Hops and bittering algorithms – rec.crafts.brewing | Google Groups: “First, IBUs are not mg of isomerized alpha acid/1 ml of beer. That’s a commonly-given definition (including in how to brew), but it’s not right. IBUs take a measurement of the acids in beer and run it through a formula designed to align with empirical bitterness data. That measurement includes not only isoalphas (humulone, cohumulone, adhumulone) but also oxidized beta acids (lupulone, colupulone, adlupulone).”

Norm Pyle’s Hops FAQ: “An IBU is defined as 1 mg/l of iso-alpha-acid in a solution. By estimating IBUs rather than HBUs, the brewer can get a more accurate (though admittedly still rough) approximation of the bitterness imparted into the beer by the hops. It is independent of batch size so that a 5 gallon batch with 29 IBU’s has the same bitterness as a 50 barrel batch with 29 IBU’s. The equations are commonly quoted from Jackie Rager’s article in the “Zymurgy” Hops and Beer Special Edition published in 1990. Revised numbers and formulae have recently been presented by Glenn Tinseth and Mark Garetz, in separate works. Rager has been taken to task for not supplying enough background references, and not fully explaining how he got his numbers. In general, his utilization estimates are believed to be optimistic. Garetz has been accused of extrapolating scant laboratory information, and overgeneralizing because of it. His numbers have been labelled unrealistic on the pessimistic side. Tinseth has just presented a revised method and set of tables, and though they are thought to be quite accurate, they have not stood the test of time. The calculated numbers tend to fall in between Rager’s and Garetz’s. Note also that these are all estimates. Actual IBUs can be measured in a laboratory, but the average homebrewer has no access to such equipment. The Rager, Garetz, and Tinseth estimation methods follow.”