By Robert L. Wolke
Wednesday, September 27, 2006
A friend of mine says she uses vodka instead of chlorine bleach to sanitize cutting boards and other kitchen surfaces after cutting up raw chicken. Does vodka have any cleaning value, or should I just use it with ice cubes?
I vote for the ice cubes.
Most vodka is 80 proof, meaning 40 percent alcohol by volume. The strongest tops out at about 100 proof, or 50 percent, but even that concentration isn't potent enough to do anything beyond making the germs happier.
Oddly, certain mixtures of alcohol and water are more effective than pure alcohol as disinfectants. The maximum disinfecting power is found at about 88 percent alcohol by volume. Hand sanitizers and medical antiseptic swabs contain about 78 percent.
But nothing disinfects as well as chlorine bleach (sodium hypochlorite), diluted at the ratio of one or two tablespoons per quart of water. I disinfect my cutting boards by first using a little dishwashing detergent to remove grease (which would prevent the bleach solution from wetting the board uniformly), then painting on the bleach solution with a pastry brush and letting it stand for 20 minutes or so before rinsing thoroughly. Any lingering chlorine odor can easily be killed by white (or any other kind of) vinegar.
A bonus: The bleach will remove stains from the cutting board.
My wife bought some tomato sauce at a farmers market in Alexandria. Its maker claimed that it contained vodka. What potential benefit could vodka provide, since vodka is 99 percent water and alcohol?
I have seen many recipes, mostly for pasta sauces, in which vodka is an ingredient. And you're right: Vodka typically is 40 percent alcohol, 60 percent water, and virtually nothing else. We can safely assume that the water contributes nothing to the sauce's flavor, but what does the alcohol do?
One thing it does not do is extract "alcohol-soluble flavor compounds" that are not soluble in water, as some food experts believe. Unpublished research I have done disproves that idea for anything less than almost pure alcohol, whereas three quarts of sauce made with a cup of vodka contains only about 3 percent alcohol.
What flavor, then, can alcohol contribute to a sauce?
Vodka has no taste, except perhaps -- as some connoisseurs will assert with boxing gloves on -- for the nuances of whatever minute traces of volatile compounds might be distilled along with the alcohol. Be that as it may, the "taste" of alcohol is nothing but a burning sensation on the tongue and mucous membranes of the mouth and throat. And even that cannot be felt at concentrations of less than about 20 percent. Add to that the fact that the taste of alcohol is hated by many people and imperceptible to many others (recent research at the University of Connecticut found that sensitivity to alcohol's taste correlates with sensitivity to bitterness), and one must wonder why anyone would put vodka into a sauce.
(Wine is an entirely different matter. Its virtues in cooking lie not in its alcohol content, but in its abundant inherent flavors.)
Studies have shown that the sensory effects of alcohol are barely discernible to most people at the concentration levels found in a sauce, especially after the sauce has been simmered and some of the alcohol has dissipated.
It appears, then, that using vodka in cooking may add a hint of something akin to bitterness, but it cannot be detected by everyone. And like most traditions, once the tradition of adding vodka began, there was no stopping it, even if nobody can remember why they're doing it. I wonder how many other questionable cooking traditions we slavishly follow simply because they make us feel sophisticated.
I would like to see the results of double-blind taste tests comparing two sauces, one made with vodka and one made with an equal amount of water. My money is in escrow, waiting to be wagered on the outcome.
This is not a joke. I have always wondered: We have cow cheese, buffalo cheese (mozzarella), goat cheese and sheep cheese. Why not pig cheese? Is it because pigs have their teats in a row, rather than a bag, or is it a chemical thing in the milk?
You're asking me, a city kid, born and raised in Brooklyn? The only pigs I ever saw there were . . . well, finish this sentence any way you like.
But through the Internet I appealed to my graduate school alma mater, Cornell University, which has a Web site called "Dear Uncle Ezra" (after founder Ezra Cornell). There I found the answer, attributed to Prof. David M. Barbano of Cornell's Department of Food Science. Here's what I learned from the professor and other sources.
Pig milk contains about 6.8 percent fat, compared with about 3.25 percent in cow milk, so it's quite rich. But sows make very little milk, so pig milk has poor commercial prospects. Furthermore, pigs are not ruminants (with four-stomach digestive tracts), so their fat doesn't contain the short-chain fatty acids produced by a ruminant's intestinal bacteria. Those fatty acids are what give cow, sheep and goat milk their distinctive flavors. So pig milk wouldn't taste very good, except, of course, to piglets.
As you suspect, there are mechanical problems as well. A dozen or so small teats would challenge the engineers who design udder kinds of milking machines, and the supply of willing and able sow milkmaids is severely limited.
Labelingo: The Web site of The Grove, a New Zealand producer of avocado oil, says its oil "is made from the first pressing of the fruit." A bit later it says, "we make just a single pressing."
Have you noticed any silly things on food labels? Send your Labelingo contributions, along with your name and town, to Food 101, Food Section, The Washington Post, 1150 15th St. NW, Washington, D.C. 20071 or to the e-mail address below.
Robert L. Wolke (http://www.robertwolke.com) is professor emeritus of chemistry at the University of Pittsburgh. His latest book is "What Einstein Told His Cook 2, The Sequel: Further Adventures in Kitchen Science" (W.W. Norton, 2005). He can be reached email@example.com.