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OK, now my wife, an exemplary cook (who has only one failing: she thinks
the smoke alarm is a cooking timer :), has a question about recipies that
call for buttermilk or sour milk: If you can make sour milk by adding
vinegar to regular milk, how can  you make substitute sour milk from a
substitute milk? Will vinegar work? -vance

P.S. I'm sorry I didn't personally answer all the replies I got about the
milk substitute. I really appreciate them, but I got so many I gave up
trying to answer them and just tried to keep up with the summary.