There are wild yeast spores floating in the air all around us
time. To harvest airborne yeast, all you need is something for them to
land on that supplies them with the moisture and sugar they need to
feed on and a warm ambient temperature of about 75° - 80° F.
you have a container of fruit juice in the back of the fridge that has
set there for weeks and the container is bulging and it has become
fizzy, that is caused by wild yeast fermentation. You can use this
liquid to make beer, bread or anything else that needs a
apple peel and lemon
Put a handful of
raisins, an apple
peel and the lemon juice from a used
lemon wedge into a glass of warm (about 110 °F)
water with sugar, about a
tablespoon of sugar for a half cup of water. Cover with a light cloth
and leave in a warm place. The
top of the fridge is usually a good place for this, as it is usually
warmer than the lower part of the room.
a cup (236
mls) of the
water in which you have boiled potatoes. Add a tablespoon of malt
Expose it to some yeast by putting it in a
wide shallow bowl and leave it out for a while and yeast should
start to grow in it. Easier to do in the summer than in the winter.
summer, look for yeast on fruit growing in the wild such as grapes,
blackberries, sloes, blueberries etc. This will be a brown, fuzzy down
on the fruit, either covering the entire berry or in splotches. Put
fruit into a bowl of sugar -water with a few drops of lemon juice.
Cover with a loose-woven, breathable cloth secured with a rubber band
and leave in a warm place.
yeast are naturally present on the skins of grapes, so grape juice made
from grapes you have pressed yourself will spontaneously ferment.
are another excellent source of wild yeast. Take a peach, don't wash it
off, cut it up with the peel on and put it in the blender with some
warm water. Add a spoonful of sugar, cover with cloth secured with an
elastic band and leave on top of the
fridge or in another warm place.
fermented apple juice (known as "scrumpy" in the English countryside)
already has a live yeast culture in it and your work done for you. In
the US, where cider is sold as soon as it is pressed from the apples
and before it has begun to ferment, you have to keep it for a while.
Eventually, apple juice pressed from apples with nothing added to kill
the yeast will ferment. You can add some raisins to speed up the
Leaves from sauerkraut
separated from sourdough batter
you make sourdough bread, the liquid that collects on top if you have
not stirred it recently contains airborne yeast. If you have some
batter that you are currently planning to use to make sourdough, just
add some water, stir, wait a day and then pour off the amount of water
that you had added. This will give you a lactic-acid fermentation,
otherwise known as "lambic beer"
white stuff that you worry about that forms on your other ferments is
from yeast. Add some sugar water and they will grow happily and you
will have your own house yeast starter.
kahm-covered leaves pulled out of the sauerkraut jar after it had
finished fermenting and put into a jar with water and sugar syrup added.
off some kefir grains
in warm water and then put them in apple juice for a week.(These
can be returned to milk afterwards. They might need a little extra time
and perhaps some extra cream in their milk to make up for their brief
no-fat diet.) If you make water kefir, you can use that as is as it
already has an available yeast culture active in it.
Kefir whey also contains wild yeast.
made from kefir whey will have some yeast that grew from the kefir and
some that was airborne when it was made. If you did not use kefir whey
to start your kvass and used only salt or other kinds of whey, there
will still be some yeast fermenting in the kvass. Add sugar and water,
cover with a light cloth and keep in a warm place until it starts to
probably don't need to the know this, but in the interest of
intellectual honesty, you can also get wild yeast cultures from moldy
bird droppings, feathers, insects and soil.
how to prepare a medium in which to grow wild yeast
or things to have on hand:
let cool and store
Have a clean glass jar.
a loosely-woven cloth cover for the jar. It should be thick enough
so that insects cannot get through the weave but loose enough to allow
the culture to breath, that is, for air to pass through. To test
air-flow, put the cloth to your mouth and see how easy it is to blow
our or in through the cloth.
Fill the glass jar about 2/3 full with warm water
Add sugar syrup at a ratio of about 1 part sugar syrup to 4 parts water
[optional] Add a teaspoon of yeast nutrient. This can be brewers or
nutritional yeast, malt extract, bread crumbs or commercial yeast
[optional] Add a 1/4 teaspoon or pinch of something acidic.
can be cream of tartar or lemon juice.
you are harvesting your wild yeast from something like raisins or
over-ripe fruit, add those. (If you use fruit, be sure to shake the jar
often while it is fermenting to prevent mold from forming.)
Cover the jar with the
cloth and secure with a rubber