I was asked recently what the difference is between macerate and marinate. There are varying interpretations in the cooking world, but here's what I was taught in culinary school smashed up with my own opinion:
While both involve soaking something in a liquid to impart the flavor of the liquid, marinating is generally done under refrigeration and can frequently involve an acidic element in the liquid, which will tenderize and begin to 'cook' the meat or whatever is being marinated. You should be aware of this, especially if you intend to marinate overnight or even longer. Doing this with potentially tough cuts of meat such as flank steak will make your next London Broil much more tender.
Macerating is done at room temperature. It most frequently involves fruits and vegetables in liquid, but macerating also refers to a technique to draw out moisture using salt or sugar. It's a good idea to salt eggplant, for example, fairly heavily for an hour before using if you want to remove some of the bitterness. As the salt enters, it bursts the cells of the eggplant, releasing moisture. Make sure you wipe off unabsorbed salt and press out the remaining liquid before breading or grilling.
Sugar is also a powerful macerating agent. Try adding sugar to shredded cabbage before making coleslaw. Let it macerate for an hour or so, pouring off the liquid that leeches from the cabbage. Your cabbage will absorb much more of whatever dressing you add later and you won't get that watery mess you see frequently. You can and should also do this with apples or other fruit before making pies.
I hope that helps. If you have any other questions about cooking techniques or food science, email me. I'll post questions I think a lot of people are curious about.
