Clearing Mead with Bentonite (clay)
1) What is Bentonite?
Bentonite is pure powdered clay and is used in wine and mead making. It
is inert and tasteless. You can get it at your local homebrew shop or
by mail order quite inexpensively.
Bentonite is used during racking to flocculate out the leftover
yeast so that it settles to the bottom, leaving crystal clear mead
behind. The clay particles are tiny flat sheets of mineral with minute
electric charges sticking out at the edges. These charges attract the
yeast cells, which then stick together in visible clumps that settle
The time to bentonite is any time after active bubbling ceases. If
you bentonite while there is still fermentation activity, the yeast
that settles to the bottom will keep bubbling and re-cloud the mead. If
you use a yeast nutrient, fermentation will proceed rapidly and cease
in a month or so. By using bentonite, your mead will be clear and ready
to bottle in a few days, freeing your carboy for more mead!
2) Bentonite Preparation
Use 1/2 tsp bentonite per gallon of mead to be clarified. To
prepare the bentonite for 5 gallons, boil 1 cup of water in a small
saucepan. Pre-measure 2 1/2 tsp of bentonite granules into a small
bowl. As the water boils, SLOWLY sprinkle in the bentonite, stirring
occasionally with a fork.
If you sprinkle it in too fast, the granules will stick together as
they absorb water, making large thick clots, which is not what you
want. If that happens, just throw it out and try again.
If you sprinkle just right into the boiling water, it will stay
soupy. Take it off of the heat and store covered for 24 hours while the
clay goes completely into suspension.
3) Racking Procedure
Fill a clean pot with water, and bring it to a rolling boil for 10
minutes to drive off all of the oxygen. This water will be used after
racking to fill up the head space. If you leave a head space after
racking, the oxygen in the head space air will get into the mead and
produce flat off flavors.
Stir the bentonite mixture with a fork to get it all into
suspension. Pour the bentonite mixture into the second (empty) carboy.
Then rack from the first carboy into the second. Avoid splashing, which
will oxygenate the mead. Top off the head space with the boiled water.
Stir the mixture thoroughly without splashing by rotating your J-tube
in the carboy.
The bentonite will bind with the yeast into visible particles and
flocculate out fairly quickly. After two days or so, it will all be
resting in the bottom 1/2 inch of the carboy.
Sometimes there is so much yeast in a mead that the first bentonite
cannot flocculate out all of the yeast. In that case, do it again. The
result will be crystal clear.
Clarifying mead with gelatin is similar to using bentonite.
Powdered unflavored gelatin is available in most grocery stores (the
Knox brand is probably the most widely known). I generally dissolve a
packet of the powder into 1 cup of cold water in a pot. Heat this on
the stove, swirling gently, until it's all dissolved. Cover it and let
it sit 20 minutes to pasteurize it. Warning: do *NOT* let this stuff
boil over! It's very difficult to clean up!
Put the pot somewhere where you can grab it easily, and start
siphoning your mead into an empty carboy. When there's a gallon or so
in the new carboy, take the gelatin solution,
and slowly drizzle it in (if you dump it directly into the empty
carboy, it will just coagulate on the bottom in a useless lump). Finish
siphoning, and stir if necessary to distribute the gelatin evenly
throughout the carboy.
Expirament with this one. You want to melt the gelatin, but you
don't want to let the water boil. I've found 45 seconds in the
microwave, stir, let sit about 2 minutes, and stir some more works well
for me. Your mileage may vary.
The two most useful things in clarifying meads, however, are giving
them sufficient time for the yeast to finish their work and dropping
the temperature 5-10 degrees. I use a spare fridge (set as warm as
possible) for about 2 weeks, reracking and adding additional gelatin if
Also, if you want a sparkling mead/cider/what-have-you, you don't
want to completely clear your brew. You'll need to leave some of the
yeast behind to ferment in the bottles and then trust time and cool
temperatures to do the rest. Pour carefully in this case so you don't
disturb the sediments!