Re: casein

From: Ryuji Suzuki ^lt;>
Date: 02/10/04-03:39:47 PM Z
Message-id: <>

Another piece of irrelevant information... at least until someone uses
casein from homemade yogurt to make prints.

From: Kate Mahoney <>
Subject: Re: casein
Date: Wed, 11 Feb 2004 09:35:15 +1300

> As chance would have it, I'm just about to make some yoghurt, went
> out and bought the milk this morning......before I got the post!!!!
> It addresses the problems of why I can't ferment from some
> commercial yoghurts - must have acid buildup -

Commercial yogurt can be used as starter culture, as long as it
contains "live active culture." There are many yogurt products which
are pasteurized after fermentation to prolong the shelf life, so you
need to avoid them. The "acid" you referred to is made by these
active bacteria as they grow (thus overfermented yogurt is sour).
There is also starter culture supplied in dry form by Lyo-San, and I
have good experience with their Yogourmet line of products. If your
homemade yogurt is too runny, there can be a number of possible
problems. Milk should be made concentrated by adding dry milk powder,
and then heat treat (like 75C for 20 to 30 min, a lot longer than
required for pasteurization of the milk -- be careful not to burn the
milk) to inactivate protein molecules (from bovine milk) that inhibit
growth of the culture. Then bring the temp down to 45C before
inoculation. Using too little starter is worse than using too
much. Also, too low temperature tends to result in acidy yogurt if
fermentation is extended to form normal texture.

When making yogurt, infrared radiation thermometer is very handy. A
dial thermometer made for sausage making purposes works just as well,
but it would be another possible source of contamination (and another
thing to disinfect before the project). This non-contact thermometer
is also very useful when grilling meat, darkroom tray processing, and
silver gelatin emulsion making (for which I would like to avoid
contact of anything metallic).

I used to have a yogurt making web page -- maybe I should edit it
again and put it back up....

For some reason I have a pile of papers on this topic... classic ones

Tamime, A. Y. and Deeth, H. C. 1980. Yogurt: technology and
biochemistry. Journal of Food Protection, 43, 939--977.

Deeth, H. C. and Tamime, A. Y. 1981. Yogurt: nutritive and therapeutic
aspects. Journal of Food Protection, 44, 78--86. (There are a lot
more new findings in this area in past few years.)

One more paper of interest...

Brabandere, A. G. and De Baerdemaeker, J. G. 1999. Effects of process
conditions on the pH development during yogurt fermentation. Journal
of Food Engineering, 41, 221-7.

Ryuji Suzuki
"Reality has always had too many heads." (Bob Dylan, Cold Irons Bound, 1997)
Received on Tue Feb 10 15:40:36 2004

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