Here are a few more questions from my backlog of reader e-mails:
Nonalcoholic beer is now widely available. Would it ever be possible to make a nonalcoholic bourbon or gin that tasted more or less like the original? How do they remove the alcohol from these products?
According to law, nonalcoholic beer may actually contain as much as 0.5 percent ethyl alcohol. It is made by brewing "regular" beer and then removing the alcohol by vacuum evaporation: putting it in a tank and pumping out most of the air.
Because alcohol evaporates much more easily than water does, the percentage of alcohol remaining in the brew is substantially diminished -- but not to zero.
There are, however, malt beverages -- made from dried, sprouted barley or other grain -- that contain no alcohol whatsoever because the malt has not been fermented. Their labels will say "alcohol-free," rather than "nonalcoholic."
In principle, one could do the same to spirits such as whiskey or gin, but that would be rather silly, inasmuch as they had already been painstakingly distilled to increase their percentage of alcohol. Moreover, in 80-proof (40 percent alcohol) whiskey or gin, the burning sensation of the alcohol is a significant part of its overall experience.
In your last column, you wrote that lacquer produced by a tropical insect is used on candies such as Reese's Pieces to provide a high gloss. If it were used on these candies, they would not be kosher, and they are certified kosher by a reliable rabbinical organization. Thus, I think something else provides the gloss on Reese's Pieces.
One would certainly think so, but no, the lacquer is both insect- derived and kosher -- in a way.
In the list of ingredients in Reese's Pieces, the insect-derived shellac appears under the pseudonym "resinous glaze." And yes, the wrapper does bear the symbol (a U in a circle) of the Union of Orthodox Jewish Congregations of America, the most prominent kashruth ("kosherness") certifying organization.
In Israel there's a saying that if you ask any two Israelis the same question, you will get three different opinions. It's pretty much the same with the dozens of kosher certification agencies in the United States (I have counted 67 different kosher symbols). Because the authors of the Torah were undoubtedly short on Reese's Pieces, contemporary interpretations must govern. Some of the certifying rabbis reject the lacquer because of its insect origin, but others approve it on grounds that it's not even a food.
Ya pays yer shekels and ya takes yer choice.
I make iced tea by pouring cooled tea over ice, filling the glass to the brim. The ice cubes are then floating on top, sticking up above the surface like icebergs. When the ice melts, why doesn't the glass overflow? They say that global warming can melt the polar ice cap and raise the level of the oceans. Why don't the melting "icebergs" in my glass of tea make it overflow?
Melting Arctic icebergs can't raise the sea level any more than your melting ice cubes can raise your tea level. It's not the icebergs whose melting would cause the problem, but the glacial ice fields -- ice that has been built up from eons of packed snow and is fixed in place, not floating on the sea. Icebergs are pieces of this ice sheet that have broken off and fallen into the sea.
As you know, when water freezes to ice, it expands. That makes ice less dense than liquid water, so it floats. Your ice cubes, protruding tops and all, melt back down into a smaller volume of water, so the overall level isn't raised. In fact, it stays the same.
A consequence of Archimedes' Principle is that the volume of liquid water coming from the melted ice is equal to the volume of water (or tea) that the floating ice had been displacing beneath the surface. So there is no change in total volume when the ice melts.
Even if all the icebergs in the Arctic were to melt, scientists agree that the sea level would not rise. But as the vast fields of glacial ice begin to melt -- and melting has been observed already -- the world market for oceanfront property will sink. Literally. Sell your vacation condo now.
Although I can generally peel oranges quite easily, I have found it impossible to peel a grapefruit by hand without splitting or tearing the fruit. So how do they produce the perfect, skinless segments found in cans?
By one method you can adopt at home, and another that you probably cannot.
In between the colored peel of a citrus fruit and the juicy inner segments is a layer of spongy white pith called the albedo. In many oranges, and especially in tangerines, the albedo and the peel aren't cemented to each other as tightly as they are in grapefruit.
There are several methods for separating the two layers.
At home, you can immerse the unpeeled fruit for a few minutes in hot or boiling water. The heat will expand the peel and puff up the gas-filled albedo. Then, after cutting off a slice from one end to start the peeling, you can separate the two layers rather easily.
In one widely used commercial method, the rinds are first scored by machine, after which the fruits are immersed completely in a solution of an albedo-digesting enzyme (pectinase) and subjected to a vacuum. The vacuum sucks the gas out of the albedo, and when air is let back in, the enzyme solution runs into the evacuated pores, where it attacks and loosens the albedo sufficiently to allow it to be removed by hand.
Why don't I get the nice, fragrant aroma of coffee when I make it each morning in my automatic coffee maker? I have used a variety of brands and the resulting coffee almost always tastes okay, but none produces that wonderful aroma. What's going on?
More than 800 volatile chemical compounds have been detected thus far in the aroma of coffee. Their molecules get to our olfactory receptors by two routes: directly though the air into the nose, and through the back of the mouth when we're actually drinking the beverage.
Most of coffee's aroma components emanate from the dry grounds and take the direct route through the air to the nose. But once the grounds are wet in your coffee maker, these gaseous compounds are trapped by the water. They reach your smell receptors only later when you drink the coffee. In fact, these back-door molecules constitute most of what we think of as the coffee's flavor.
So you really are experiencing the aroma chemicals you love, but in the form of flavor, rather than as an airborne bouquet.
Robert L. Wolke (www.professor science.com) is professor emeritus of chemistry at the University of Pittsburgh and the author, most recently, of "What Einstein Told His Cook: Kitchen Science Explained" (W.W. Norton). He can be reached at wolke@pitt.edu.
