What
Is Cheese?
So what is cheese exactly?
Basically, cheese is milk that has been acidified until it
separates
into curds (milk solids) and whey.
There
are two ways to achieve this.
1.
adding
an acid such as vinegar or lemon juice to hot milk
2.
using
a bacterial culture to acidify the milk and then adding rennet to
separate the
milk.
The most basic cheeses are the acid
cheeses such as the ricotta. The high
temperature allows the vinegar to
quickly coagulate the milk, the whey is drained off, and you have
cheese. The benefits of making these acid cheeses
are several:
1.
They
are quick and easy to do, so if you have lots of extra milk but not
extra time
to do much with it, you can have cheese without much work.
2.
Usually,
the yield of cheese from the milk is fairly high.
3. During the winter months,
when there are higher levels of milk solids in the milk, it is easy to
simply add more acid to ensure that all the solids
are separated from the
whey.
On the other hand, these cheeses
are very limited in diversity of flavor and consistency.
The acid cheeses will help you to understand
the basic chemistry of cheese making,
but once you’ve made them a few times,
you’ll want to branch out to the rennet coagulated (cultured) cheese.
All cultured cheeses are made with
the same ingredients: milk, bacterial
culture, and rennet. What creates the
variety of cheese from a soft chevre to an aged cheddar
is not the ingredients,
but how the ingredients are used.
Temperature and time play a very important part in making
cultured
cheeses.
We'll start with the bacterial culture. The cheese making
bacteria turn the lactose in the milk into lactic acid. Different
bacteria work optimally at different
temperatures and there are two types of culture: mesophilic
(moderate temperature loving) and thermophilic (hot temperature loving). Mesophilic cultures
produce chevre, feta,
cheddar, Gouda,
Colby among others. Thermophilic
cultures are used for Parmesan, Romano, other Italian cheeses and Swiss
cheeses.
There are two forms of cheese culture which you can use. The
most
readily available are in your grocery store: buttermilk (mesophilic
culture)
and
yogurt (thermophilic culture). The
benefit to using buttermilk or yogurt is that you can run to the store
and buy
a container and be all ready to make cheese.
On the other hand, results can be less consistent, and
there is the
possibility of contamination especially if you culture your own
buttermilk or
yogurt.
The other option is to buy a Direct
Set culture. This is a freeze dried
bacterial culture which will retain its potency for over a
year if stored in
the freezer.
The benefits to the Direct
Set cultures are as follows:
1.
They
consist of high quality cheese making bacteria giving a better chance
for
consistent and flavorful results.
2.
You
do not make a culture from it which you then use in the cheese. It is a ready made culture.
This eliminates the possibility of
contamination.
3.
A
little bit goes a long way.
Direct Set cultures can be
purchased through goat supply and cheese making supply companies. However, for people who are interested, I
suggest
purchasing the cultures from a wholesale cheese making
supply
company called Dairy
Connection.
Let me point out again that
pasteurization of the milk ensures that only
the added bacteria are present in
the milk during cheese making.
When
using raw milk, the cheese making bacteria have to compete with
naturally
occurring bacteria, and the result can be not just unpleasant,
but possibly
unsafe. Don’t take a chance that your hard
work will be ruined by failing to pasteurize your milk.
Once the bacteria have been given
time to act (at a temperature and for a time specified by the
individual
recipe), rennet is added to
coagulate the milk. Do not use Junket
rennet available in grocery stores. It
does not have the strength for cheese
making. Rennet can be purchased
through
goat supply or cheese making companies as a liquid or as tablets. It can be a vegetable or an animal
derivative. Although there does not seem
to be much difference between the vegetable and animal rennet, the
liquid
rennet is much easier to measure, and I prefer it to the tablets. Rennet must
be added in the correct
amount. If you don’t add enough, the
milk won’t set. If you use too much, the
cheese will be bitter.
Here again, time and temperature play an important role. Rennet
works best in milk with a higher acid content. If you add the
rennet before the culture
has had time to acidify the milk, the resulting curds will be weak and
unworkable. If you wait too long to add the rennet, you
may end up with a very
sour cheese. Pay
close attention to the times and temperatures indicated in your recipe. Have a good thermometer. But
remember that people have been
making
cheese for thousands of years without modern equipment.
Pay attention to the directions, but don’t
obsess about them and don’t feel that cheese making
is too complicated to
try. You can turn that
milk into cheese, and with a little attention to
directions, it will be a very good cheese.