Book offers 'hole' lot of answers to foil mystery
Oh, summer vacation, you came and went. So little time, so much to learn.
For instance, on a trip to the East Coast, I found the answer to a two-year-old culinary conundrum that nearly foiled a special meal.
Let's go back to 2006. Family was visiting Chicago and a celebratory meal was on the menu at home: au gratin potatoes, an orange and almond sauce over broccoli and, the centerpiece, steaks in mushroom sauce. The overnight marinade for the beef fillets was something: sour cream, chives, mayonnaise, red wine, buttermilk, Roquefort cheese, Worcestershire sauce, lemon, vinegar and various wines. The only thing handy to hold all those fillets (there were 8) and marinade was a large baking pan. After it was put together, the whole, beautiful thing was covered with aluminum foil and put in the refrigerator.
That was Friday night. By Saturday night, when the steaks were pulled from the refrigerator, there were tiny holes in the foil.
While there didn't seem to be foil on the meat, I was concerned. One of our guests, a veteran in the kitchen, assured us it was fine to go ahead and throw the meat on the grill.
The meal, the wine, the conversation -- all of it was terrific. No blackened pieces of foil in the steak. But just exactly what happened to that foil has always gnawed at me a bit.
That is, until a June night in Maine when, tired of the book I was reading, I pulled Robert L. Wolke's What Einstein Told His Cook off the bookshelf from the home of a family member.
Sprinkled among the science lessons and recipes from the professor and one-time Washington Post food writer's book are letters from readers, including one who encountered the foil conundrum. The reader had covered leftover lasagna and found that on the portions of the foil that had touched the food, there were tiny holes. Wolke explains that because aluminum is an active metal, it can be attacked by citric and other acids -- from such things as organic tomatoes. In my case, the vinegar and lemon in the marinade might have produced the acid.
He goes on, to discuss how the lasagna-maker's tomato sauce wasn't the likely foil-chewing culprit. That's because tomato sauce alone can't necessarily chew through the foil. He was betting the cook used a stainless steel container that, when paired with a different metal -- in this case the different metal was the aluminum foil -- and tomato sauce the three create a battery of sorts that eats up the foil, Wolke explains. (Aluminum on aluminum, which would have been the case with my baking pan and the aluminum foil covering, wouldn't have the same effect.)
The answer, he says, is to just be careful when storing tomato or any acidic sauce. If it's in a metal bowl and you're covering it with foil -- just make sure the foil isn't touching the food.
Then again, a glass container might be the best bet.
Now, how to store all that coastal air and fresh pine scent and bring it back to Chicago.
Curious about an unusual edible or kitchen tool? Want to share some mysteries in your own cabinets? E-mail the Food Detective at ldonovan@suntimes.com.