Jonathan Sachs wrote:
> I recently bought a yogurt maker, and have used it about a half dozen
> times. I'm having a problem reusing one batch of yogurt starter for
> the next. The instructions warned me that after a few batches the
> starter would get "tired," and I would have to start over with
> commercial starter. That would be fine, but the starter is not
> lasting for a few batches. The first time I use it the result is
> thinner than the original; the second time it's unusable.
>
> I'm following the directions I got, but they're vague. I wonder if
> I'm doing something wrong. I put a half cup of each new batch in a
> separate clean container, which I store in the fridge next to the
> regular container. When I make the next batch I stir in the half cup
> just before I put the batch in the yogurt maker.
>
> Any ideas?


I haven't made any yogurt in a couple of months, but I use commercial
"fruit on bottom" yogurt (before stirring it) as a first starter. I
make the yogurt in an insulated 1 liter mug, and when it's about empty I
just fill it up with heated milk and stir, using the leftovers of the
previous batch for a starter. After 4 or 5 generations, I'm usually
tired of yogurt and stop making it for a while.

Scalding the milk and letting it cool to 110° seems to produce a thicker
yogurt. I'm not sure why; probably has to do with denaturing the milk
proteins more than killing any competing bacteria.

Best regards,
Bob