Getting more or less flavour out of garlic and onions is all about controlling their chemical weapons, according to a scientist who's studied them for at least 40 years. Learn how mincing, rinsing, cooking and crushing the pungent stuff affects your dishes.
In a review of Garlic and Other Alliums: The Lore and the Science, food science writer Harold McGee details the findings of Dr Eric Block that you can use in the kitchen. In detailing the sulphurous compounds that have kept animals and insects at bay, but which humans have adapted to consider an essential flavour to many dishes, Block offers some tips on handling onions and garlic in dishes so that that they don't overwhelm:
If you're using onions or garlic or chives raw, in a dressing or salsa, either chop them just before serving or rinse the chopped pieces thoroughly. Water removes the harsh aging sulfur compounds from the cut surfaces, so you'll taste only the fresh ones.
If you're heating garlic or onions or their relatives, then cooking whole or coarsely chopped bulbs will moderate their flavor. Crushing or grating will intensify it.
Crushing can also diversify the flavors that alliums contribute to cooked dishes. They're valuable ingredients in part because their sulfur chemistry suggests and reinforces savory meat flavors. Last year a German study of meat stews found that by far the strongest contributor to the overall "gravy" aroma was an unusual sulfur compound that came not from the meat, but from the onions and leeks. And that compound appears only after these vegetables have been cut up.
As a bonus tip, Block's book suggests that while garlic has deep-down, breath-destroying properties that no mere mint can overcome, eating raw kiwis, eggplants, mushrooms or parsley can fight the flavour you don't want lingering around. For more onion-wrangling advice, read up on toning down onion intensity and staying tear-free while cutting the suckers with a water soak, refrigeration or a properly sharp kinife.
What's your best tip when it comes to the stronger components of cooking?