From: morgana@infonode.ingr.com (Angela Morgan)
Subject: Re: Yogurt question
Organization: Intergraph Corporation, Huntsville, AL.
Date: Tue, 25 Aug 1992 23:18:09 GMT

jcp@islay.dco.dec.com (Jolly C. Pancakes) writes:

>	Question for you do-it-yourself yogurt makers - some have
>mentioned heating the milk to 180 and then cooling it. Others don't
>mention heating or warming the milk at all. Why 180 degrees F? Why not
>just "room temperature" or "lukewarm"?

There is an enzyme in milk which inhibits the lactobacillus growth
(said growth being what makes the milk into yogurt).  This enzyme is
destroyed by heating the milk to 180 degrees F.  I read in a couple of
places that it is not necessary to heat milk that has been pasteurized,
because the pasteurization process supposedly destroys the enzyme.
However, the couple of times I tried making yogurt *without* heating
the milk, I had very poor results, so I don't believe that pasteurization
necessarily will destroy all of the enzyme.

For several years now, I have been making my own yogurt with excellent
results.  I use a yogurt maker that makes 1/2 gallon at a time; however,
it's not necessary to have a yogurt maker.  What *is* important is to
keep the milk at 111-115 degrees F for the incubation period.  As
someone said in an earlier post, putting the milk in an oven with the
pilot light on works pretty well.

I've seen several posts lately asking for info on making yogurt, so I
guess I'll include my procedure here (as long as I'm posting something):

1.  Heat 1/2 gallon of whole milk to 180 degrees F (I use a thermometer).
    Use a nonreactive saucepan (stainless steel, enamel, or glass).
2.  Remove from heat and allow to cool to around 113 degrees F (again,
    I use a thermometer).  This process may be quickened by immersing
    the pan in ice water.
3.  Pour the milk into the yogurt-maker container (or whatever you're
    using; should be glass or hard clear plastic), through a strainer.
    The strainer removes any lumps that might be in the milk, such as
    from the skim that forms on the top during cooling.
4.  Measure 1/2 cup of existing yogurt (for starter) into a 2-cup
    container.  Add about 1-1/2 cups of the warm milk.  Mix the yogurt
    with the milk using a wire whisk.  Pour this yogurt-milk mixture
    into the rest of the milk, again through a strainer.
5.  Stir the milk very, very well.
6.  If you have a means of keeping the milk at 111-115 degrees F, it
    takes about 5 hours to make wonderful firm yogurt.  After this time,
    place the yogurt in the refrigerator.  It takes about 8 hours for
    it to get cold throughout and reach maximum firmness.

I use whole milk because it's easier and I'm not too worried about fat.
Lowfat or nonfat milk can be used, but it turns out very thin unless
milk solids (i.e., nonfat dry milk) and/or gelatin are used.  I have used
lowfat milk with added milk solids and gelatin, with excellent results.
Different amounts of milk solids and/or gelatin can be used to obtain
yogurt that ranges from very light to very firm.  (If anyone wants any
more details on this, email me.)

My yogurt culture seems to diminish with each generation (and it's hard
to get the yogurt as firm as I like), so I almost always buy some plain
yogurt (with live cultures) to use as a starter.  Be careful; some
yogurts claim they have live cultures but I have found that many do not.
The only yogurt I have found that consistently works is Dannon.  I used
to use freeze-dried starter.  With that, the culture doesn't diminish as
fast, but it still diminishes eventually and the freeze-dried starter is
quite expensive.  Buying an 8-oz. container of Dannon each time I make
yogurt is quite a lot cheaper in the long run.  The drawback to using
commercial yogurt is that you don't have any control over how much of
which lactobacilli it contains (i.e., L. acidophilus vs. L. bulgaricus,
etc.), which is important to some people.

Hope this helps.

                                    Angela

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