While brewers like to claim that they
make beer, it is actually the yeast
that turn our prepared sugar solution into
an alcoholic beverage. During this process
we brewers mostly wait—although some
amount of watching is useful as well. This
article discusses fermentation and your role
as the brewer. It begins by describing a
more desirable technique for preparation
and pitching of dry yeast and then continues
with a discussion on fermentation itself.
After the fermentation is over, you’ll be
ready for bottling.
Pitching Dry Yeast
Each time you make beer, you’ll be
adding yeast once the temperature of
the wort drops below 75° F (24° C) or
lower. While you can sprinkle dry yeast
on top of the cool wort as we did in the
first recipe, you’ll improve the probability
for success if you take a few minutes
to prepare the yeast for the feast it is
about to receive.
To do this, you’ll run warm (about 98-100°
F or 37-38° C) water into a clean and sanitized
cup, bowl or measuring cup. Open
the yeast packet and pour it onto the warm
water without stirring. Allow the yeast to
dissolve in the warm water for about 10
minutes then stir in with a clean spoon.
Once prepared, this yeast slurry can be
added to the cool wort in the fermenter.
Then you will attach the lid and fermentation
lock. (Don’t forget to put some water in
the fermentation lock to serve as an airflow
barrier.) Fermentation should start within
24 hours. During fermentation, you’ll want
to store the fermenter someplace where the
temperature will stay around 65° to 75°
(18°-24° C). If you have any control over it,
the cooler end of this range is better than
the warmer end.
By the way, if you buy a package of dry
yeast and don’t use it, toss it in the
refrigerator until you do need it. This
will help to sustain the freshness and
vitality of the yeast.
Liquid Yeasts
Many homebrewers use liquid yeast
preparations as an alternative to the
packages of dry yeast. Liquid yeasts tend
to cost more than dry yeast packages, but
they can be well worth it in terms of beer
quality and brewing convenience. There
is a much wider variety of liquid yeasts
than there is of dry yeast. Each type produces
different characteristics in the finished
beer and often you must use a special
yeast type when you want to copy a
particular commercial beer that you like.
Liquid yeasts come in packages that contain
enough yeast for a 5- gallon batch.
One style comes in a foil pouch. To use
it, slap the pouch to break a small wort
package inside and incubate the package
for three hours. The expanded pack is
ready to be pitched into the beer.
Another brand of liquid yeast comes in a
vial about the size of a small safety flare.
The contents of the vial can be pitched
directly into the wort
Liquid yeast packages have a more limited
shelf life than dry yeast. Liquid yeasts
carry a date indicating when they were
filled by the manufacturer or a bestbefore
date.
Fermentation
If it is convenient, you’ll want to check
the fermenting brew every 12 to 24
hours for activity. If all goes well, you
should see vigorous activity within the
first day. This will be indicated by rapid
bubbling of carbon dioxide out of the
fermentation lock and also by the development
of foam, called kraeusen, at the
top of the liquid level. This is usually visible
from the outside even with opaque
white plastic fermenters.
Once this has happened, you know that
everything will be OK. In a week or so,
your beer will be ready to bottle.
If you don’t see any signs of fermentation
activity within the first 48 hours,
there may be trouble. Generally, the
best approach is to wait it out. If you’ve
been away for a couple of days or forgot
to check for activity during the first
48 hours, it may have done its thing
while you were away. In this case you
should still see a ring of gunk around
the top edge.
If you get a quick initial fermentation
(within 48 hours), you’ll most likely be
ready to bottle five to seven days after
the brew day. Follow the instructions for
bottling on page 27. If your fermentation
starts more slowly, you must wait
until all activity has ceased before you
think about bottling. Check the fermentation
lock every day or so and when
you can see no more visible bubbling,
wait another three to five days before
proceeding to bottling.
If you fail to notice any signs of fermentation
after a week, you may open the fermenter
and check on things. Before you do
this, clean and sanitize both the inside and
outside of a measuring cup. Use this to collect
about a one-cup sample of the beer or
wort once you have removed the airlock
and lid. Once the sample is collected,
replace the lid and airlock. Now you have a
sample of your beer and you can assess its
condition. First, if you have a hydrometer,
fill the hydrometer tube and take a reading.
If the reading is at or below 1.020, then
you’ve had a successful fermentation.
Whether you have a hydrometer or not,
you can also taste the beer. If it is thick
and tastes very sweet and syrupy, then it
most likely has not fermented. If it has
the general properties of beer (minus the
carbonation at this point), then you are
on the right track. In either case, don’t
return the sample to your fermenter—it
can contaminate the batch. If you are in
doubt, save the sample in the refrigerator
and ask the folks at HomeBrew4Less.com
at your earliest convenience—
they’ll be glad to help out