AIR-LOCK BASICS


- What Is An Air-Lock?

An air-lock is a small device, that when filled partially with
water, acts as a water trap. It attaches to the top of a
fermentation vessel and allows the gases caused by a fermentation
to percolate through it and out of the vessel without allowing
contaminants to get to the must.

The water that is put in the air-lock creates an effective
environmental barrier. It keeps unwanted, air-born matter and
bugs, regardless of how small, from getting through the air-lock
and to your precious wine.

Air-locks come in two basic designs for the home winemaker: the
"sink-trap" design and the "cylinder" design. Examples of both
can be found at the links below:

Senior Air Lock (cylinder shape)

Triple Bubbler Lock (sink-trap design)

- How Do You Use An Air-Lock?

Regardless of which air-lock you choose, both are used in the
same manner. They are attached to a hole or opening of a
fermentation vessel with the aid of a rubber stopper, such as the
ones found at the following link:

Rubber Stoppers

The size of rubber stopper you will need is determined by the
size of opening to which the air-lock is being fitted. Once you
have the correct size rubber stopper, you can attach the air-lock
by placing its stem into the hole of the rubber stopper and then
putting the rubber stopper into the hole or opening of the
container.

After you have the air-lock in place, fill it approximately half
full with water. Be sure to put the dust cap back on the air-
lock. These caps have either ridges or pin-holes that still
allows the gasses to make their way out.


- When Do You Use An Air-Lock?

One of the major misconceptions surrounding air-locks is that
they should be used at the very beginning of a fermentation. But,
nothing could be further from the truth.

For the first few days of fermentation, also known as the
"primary fermentation", your juice should be exposed to air, not
isolated from it. Just cover your fermenter with a secured lent-
free towel or something similar during this time.

There are two major reasons why an air-lock should not be used
during the primary fermentation:

The first reason is that there is so much gas being produced
during these first few days that an air-lock could not keep up
anyway. The massive amounts of gas would simply blow the water
out of the air-lock.

In fact, the current of gas is so high during the primary
fermentation that small air-born particles and other contaminants
can not even get to the juice. Bugs will not crawl into this type
of environment either as this amount of gas is simply not
hospitable to their survival.

The second and more important reason for not using an air-lock
during the primary stage of fermentation is because air is vital
to the start-up of a healthy, vigorous fermentation. Yeast needs
air to multiply in to great enough numbers to ferment properly.

Wine yeast has been programmed to multiply during the primary
fermentation. Later on in the fermentation they will multiply
some, but nothing to the extent they do during the primary
fermentation. Typically during the first 3 to 5 days of
fermentation, yeast will multiply to around 100 to 150 times the
amount you originally added.

If an air-lock is used during this growth stage, the yeast
becomes stymied by the lack of oxygen and unable to multiply to
sufficient numbers. The result is a long drawn-out, sluggish
fermentation that can produce some slight off-flavors in your
wine. All symptoms of over-worked yeast. In other words, too few
yeast cells trying to do too much work.

For these reasons we recommend using an air-lock only after the
first racking of the juice. This is usually around the 5th to 7th
day of fermentation. Most recipes will have a recommended number
of days that will specifically apply to the wine you are making.

Or, you can use a hydrometer to judge when the first racking
should be performed. Usually the optimum time to rack your wine
is when it reaches a Specific Gravity reading of 1.035 to 1.025
on your hydrometer.

Anytime after this first racking, an air-lock should be used. It
plays an extremely vital role in protecting your must as the
fermentation starts to slow down in its later stages. It is
during this 3 to 5 weeks of slower "secondary fermentation" that
your juice becomes most susceptible to contamination from outside
sources.


For more information about the hydrometers we offer go to:

Hydrometers

- Related Articles:

"Fermentation 101"

"Top Ten Reasons For Fermentation Failure"

"Hydrometer Scales And What They Mean"

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E. C. Kraus

Home Wine & Beer Making Supplies

Address: 733 S. Northern Blvd. - P. O. Box 7850 - Independence, MO  64053

Phone:(816) 254-7448  Fax:(816) 254-7051  Toll Free: (800) 353-1906

Email: customerservice@eckraus.com

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