A Question from Alton

[Jason Perlow]

Mr. Mcgee -- thanks again for spending your valuable time on this wonderful Q&A.

I asked Alton Brown, another notable food writer who has his hand in food science, if he was interested in asking you any food science questions -- he responded with the following:

Jason,

I would never even pretend to be able to come up with a question worthy of Mr. McGee's time. I'm simply not worthy.

But if you want you could ask him about the effercts of heat on acidity.  For instance, when cooking down a wine sauce, does the acidity always increase and if so, is the rate of increase predictable?  Is it a constant curve and what are the factors that effect it. I realize of course that the perceived acidity seems to go down in many cases due to the increase in sugar, but the acidity is still there. Anyway, if I wasn't a gutless scaredy cat, I'd ask him about that.

[Harold McGee]

Alton protests too much! He’s a great communicator and I’m sure has gotten more good kitchen science out to more people than anybody else.

The acids in wine are “non-volatile,” so they don’t boil off with the alcohol and water, and therefore do get more and more concentrated. Boil wine dry and you’re essentially left with cream of tartar. But the perceived acidity of the sauce depends on the balance of the other components, most of which are also getting more concentrated—the salts, sugars, maybe tannins. So the overall effect might be not that the sauce tastes more sour, but that it tastes stronger. And if the sauce does taste more sour, less balanced, then the cook readjusts the balance by seasoning it.