"Unless you are using sweet, height-of-summer tomatoes, chances are your tomato sauce will taste more tart than you might like. Many recipes call for adding a pince of sugar... but sugar doesn't eliminate the tartness; it just makes the sauce sweeter. Nevertheless, I did that for years until my scientist husband reminded me that the way to neutralize an acid is with a base. He suggested adding a pinch of baking soda to overly tart tomato sauce.
"It works like a charm. You don't need much baking soda to have an impact, so start with a pinch. The sauce will foam briefly as you stir it in. Let the sauce simmer for a minute or so, then taste again. Add a little more baking soda if necessary. Be careful not to add too much or your sauce will taste soapy."
From the cookbook Four Seasons Pasta, by Janet Fletcher, p. 26.
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