from the President:
Visits to Europe and Asia
By Chris White
Recent visits to breweries in Singapore and Korea
remind me how global our business has become. But it also demonstrated
to me that brewers everywhere have similar questions regarding yeast and
During a talk to Korean brewers, I was asked whether
it was acceptable to buy our homebrew vials and grow up the yeast for
larger volumes of beer.
This is a question I hear occasionally when I talk to
professional brewers, especially in foreign countries where shipping
costs may be higher. The answer may be instructive to a lot of our
readers. The bottom line is, growing up the yeast can work under certain
conditions, but it does invite a host of possible problems. It takes a
long time to grow yeast from a small amount of yeast to a large volume.
For us, it takes three weeks to grow yeast up from slants (part of this
process involves quality control testing in the laboratory before,
during and after the growth process).
When growing up yeast, brewers can unintentionally
introduce bacteria into the picture (when it leaves our laboratory, the
yeast is certified 100 percent free of bacteria). This is because when
you have large volumes of yeast, you have billions of cells that can
fight off contamination. When growing up the yeast, you have far fewer
"soldiers" to fight off these intruders.
If you are culturing up from a slant or a vial,
brewers will need an autoclave or pressure cooker to sterilize the
equipment. After the growth process you will need to plate it on
sterilized media to make sure you have not introduced any contamination.
Most small brewers do not have the time, interest, or training in these
tasks. In my opinion, your time is better spent on the final product and
making sure the beer that you release is the of the highest quality. By
the way, after my talk in Korea, another brewer came up to me and said
the guy who grows up his yeast from vials has contamination problems.
You may be interested in learning a little more about
my visit to Korea, which has a growing beer culture and more than 100
microbreweries. Most of these brewers were trained by Germans and every
place I visited featured three beers: pilsners, dunkles and weizens.
They were all unfiltered (one brewer told me they kept their beers
unfiltered because this distinguished them from mass produced beers).
The brewers are a close group who are aiming to make
better beer available to their peers. I expect to hear of great progress
from these breweries in the years to come.
Chris White is President of White Labs Inc. and is
a chemistry and biochemistry lecturer at the University of California,
San Diego. He has a Ph.D in biochemistry. Feel free to write
him about this column.