May / June, 2004
Making Alcohol at School
Publisher Michigan Beer Guide, Leonard, MI
Article reprinted with permission of the author
and American Distilling Institute, Hayward, CA.
The
weekend class was set up by Professor
Kris Berglund of Michigan State University (MSU) and drew students
from all over North America. “We expected about 12 or 15 folks to
show an interest,” said Berglund, “But we got 50 to sign up,
followed by another 20 already on a waiting list.” Berglund anticipated
interest to be primarily from Michigan and surrounding states, so it was
with great surprise that attendees flew in from as far away as Maine,
Georgia, California and even Canada. In fact only about a third of the
audience were Michigan residents and they all were experienced brewers
and wine makers.
In attendance from Michigan were representatives from wine makers Cory
Lake, Heart of the Vineyard, Black Star Farms and St. Julian (all of which
have stills) and brewers from Big Rock Chop House and New Holland Brewing
Company (neither of which have stills), and the two members of the press,
us.
The three-day class was lead by Berglund but featured German still manufacturer
Alexander Plank of Christian Carl and introduced his Philadelphia based
representative Nicholas Haase of B&D Technologies.
Alexander Plank is the fifth generation of the Carl family since it began their still manufacturing business in 1869.
“Christian Carl,” stressed Plank, “is more than a still manufacturer.” He explained that producing the still is only one of seven steps that they take in getting a still from "the house of Carl to your house.” He identified the seven steps as consulting, planning, contracting, manufacturing, installation, start up, and support.
It was this degree of commitment and customer service that led to the
purchase of all nine stills in Michigan from Christian Carl.
The first two days of the introductory three-day course were held on campus.
We first met in a classroom where we gathered handouts and listened to
four hours of lecture supported by PowerPoint and overhead visual aids.
Plank introduced us to the different stills, their advantages and disadvantages
and provided an in depth review of the modern pot still. Berglund forgivingly
dealt with the chemistry.
The classroom was followed up Saturday in the MSU distillery where the
theory was manifested with the application of running a number of charges
through the University’s Christian Carl pot still.
Day three was optional yet attended eagerly by the majority of the participants.
A field trip to Leopold Bros. Brewing Company of Ann Arbor further strengthened
the practical application as we observed a charge run through their pot
still located in the brewhouse.
The Christian Carl still at Leopold has only been in use for a few months,
but brewer Todd Leopold said he is already completely comfortable with
the system and its operation. In fact, he installed the system himself.
This added to a body of evidence my mind was building from class questions
and observations that the brewers in attendance (and I include myself
in this group) had a small advantage in learning about distilling. Breweries
and distilleries use the same construction materials, boiler steam generation,
fluid management, clean in place (CIP) regimens and brewers already know
all about yeast, fermentation, and alcohol production.
A review of some of the highlights has to include Berglund’s little
tail that he used to begin the class. He called it “the secret of
distilling.’ It was a good story but I’ll not take the time
here to tell it when I can just cut to the punch line. “The secret
to distilling is that the distiller only drinks his mistakes and sells
only his very best to the customer.
This ideal was echoed by Plank who repeatedly said that it was very important
to start with high quality ingredients to make a top quality product.
To this, one must learn and understand the concept of heads, hearts and
tails. In an effort to increase volume, the distiller is tempted to add
heads and tails cuts to the hearts cuts, which in effect increases volume
but at the cost of lowering quality.
Though somewhat challenged by the English language, Plank managed to very
carefully explain distillation processes from the days of the alchemist
to today’s continuous still and the modern pot still. The problems
with the earlier simpler stills were high heat generation and inefficiency.
Early stills used direct fire, which required lots of fuel and produced
excessive heat. The charge would distill rapidly, but only increase alcohol
to about double its original strength. A five percent beer would have
to be distilled three times to reach 80 percent strength. Plank said that
time on heat is detrimental to the quality of the product, so the need
for repeated passes through a very hot still in effect beats up the distillate,
stripping good volatiles and actually adding unwanted chemical compounds.
Whiskey makers who still use this method also have to age their distillate
on wood. Years of wood maturation acts not only to add aroma, flavor and
color, but softens the product by removing those unwanted compounds.
Plank’s focus of course was on the modern pot still that requires
lower heat and yet very effectively distills a beer or low wine of 5-12
percent alcohol by volume to a distillate exceeding 80 percent in a single
pass. The advantage to the lower heat, less time equation is not only
cost and energy savings, but also a distillate that retains more of the
original character of the raw material. This is of great import to fruit
distillers wishing to retain the subtle aromas and flavors of the original
ingredient.
The single pass higher alcohol content is achieved with a column of plates
installed above the still in what is called the helmet. The number of
plates is determined by the buyers needs. A taller helmet with more steps,
called plates, is required to produce an end product of greater alcohol
strength. Many distillers only require three plates, but one example was
mentioned having 45.
Each plate is a step surface where “equilibrium” is achieved
between the alcohol vapor (gas) and the alcohol liquid. At that surface,
the alcohol vapor continues up to the next plate, while the liquid remains
or falls back down to the plate below. As the alcohol vapor makes it way
up the column from plate to plate, the alcohol by volume increases. Ultimately,
only water is left in the pot. Because alcohol vaporizes at 73º C,
when the pot is boiling at 103ºC, only water remains and all the
alcohol has been stripped.The first step is the easiest and where the
greatest amount of rectification is achieved, beyond that, each step gets
harder and the amount of rectification less.
What solidified the whole process in my mind was watching 38 gallons of
11.5% wine turn into about 2 gallons of 87%ABV distillate in about 1.5
hours. The still was then rinsed internally and another charge added so
within minutes the whole process was run all over again.
Of course, not all of the resulting distillate was the good stuff. The
distillate, which was captured into 0.5-liter cuts, was diluted to 40
percent alcohol. We were then allowed to sensory evaluate the results.
The first five cuts were determined to be heads, full of higher alcohols
and in most cases disposed of. The next nine were the hearts and represented
the best of the batch – the secret of distillation. The last 18
were the tails, which can be saved and redistilled.
I must say it was a great class with lots of camaraderie among the attendees,
experienced and non-experienced alike. To paraphrase Kris Berglund it’s
kind of like a club - where all the members help each other. That’s
certainly the case at MSU.
Professor Berglund can be reached at
berglund@msu.edu or 517-353-4565.
Rex Halfpenny together with his wife Mary are desktop publishers working out of their home in Leonard, Michigan. They publish the Michigan Beer Guide (www.michiganbeerguide.com), a periodical dedicated to the brewing, wine and alcohol industries in the Great Lakes State.They also published this directory for ADI.
Biosystems & Agricultural Engineering
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June 4, 2004
