Two coffee cans taped together, an incandescent bulb for heat, a thermometer, and a cover cloth are all the equipment you need for a yogurt incubator.
ILLUSTRATION: KIM ZARNEY
There is an alternative to the sugared,
chemicalized, flavor-enhanced yogurt found in the
supermarket. You can grow your own yogurt culture at home —
at a fraction of the cost — in a simple, never-fail
yogurt incubator made from two metal cans, an electric cord, a
75-watt bulb, and a thermometer!
First find two good-sized cans of approximately the same
diameter (three-pound coffee cans work well). Also get an
electric cord with a light socket on one end and a plug on
Now, in the bottom of one of the cans (the smaller one, if
they aren't the same size), punch a hole just large enough
to allow you to thread in the plug of the cord. Pull the
plug all the way through the hole and leave the socket
inside the can. Screw a regular 75-watt bulb (I don't think
the Soft-White type will work as well) into the socket. Put
the other can, bottom down, on top of the
first and you're ready to go. Now for the yogurt.
Find a large clean glass jar that will fit
comfortably, with space around its sides, into the top can. Fill the jar with warm milk (not too hot
— about 100°-120° Fahrenheit). If you're using
reconstituted (non-instant) powdered milk, add a large can
of evaporated milk to the full jar. Now mix in 2 to 4
heaping tablespoons of the tastiest yogurt you can find
(natural flavor is best, but the fruits work too). The more
you use the faster the batch will congeal.
Fill the top can of your incubator about half full with
water warm enough to register between 110° and 120°
F. on the thermometer. Set the jar in the can and check to
make sure the water comes up at least even with the yogurt
inside the glass container. In other words, all the yogurt
should be below the level of the warm water outside. Now
cover the top of the jar with a clean cloth, plug in the
cord and put your incubator where it won't be disturbed for
about four hours.
The 75-watt bulb should keep the temperature of the water
fairly constant. Anywhere between 100° and 120° F.
is OK, but just to make sure, check the water with
the thermometer every once in a while the first time you
If for some reason a 75-watt bulb doesn't maintain the
proper temperature, try one a little larger or
smaller as necessary.
After four hours have passed, check the yogurt with a spoon
or by tilting the jar slightly. Gently, though, or the
culture might curdle. If the yogurt hasn't congealed, let
it incubate another half-hour or so and test again (ours
usually takes 4 1/2 hours). When the culture's consistency
is to your liking, put a cover on the jar and pop it into
the refrigerator. Additional incubation makes yogurt
increasingly sour, so incubate yours to taste and stop.
When the culture has cooled, it's all ready to eat.
Dig into the yogurt as is, with a little honey and fruit,
with prunes or, whatever your imagination desires. Just don't forget to save a few spoonfuls
to start your next batch!