Does Vodka Sauce Really Need Vodka?
"I like penne alla vodka sauce. I'm curious whether or not the vodka adds anything to the mix. I'm dubious that A) the alcohol in the vodka actually brings any additional flavors out of tomatoes as people claim, and B) that one could even taste these nuances in tomato flavor after dumping a bunch of cream into the sauce. I'd be interested in a food lab investigation: does alcohol in fact draw out flavor from tomatoes?"
—Sent by ctblair
It's not exactly clear where Penne alla Vodka comes from. Some say it's Italian, some say it's Italian-American, others claim it was invented by vodka manufacturers who tried to pass it off as Italian. All we do know for sure is that the dish—penne pasta tossed in a smooth, creamy sauce made with tomatoes, cream, and a splash of vodka—became popular in the U.S. some time in the late '70s and early '80s
Its history may be muddled, but its flavors are crystal clear. Simultaneously rich with cream but with a sharp, bright flavor from the vodka and crushed red pepper, it's the kind of sauce that's comforting in cold weather but makes you think of the warmer months ahead.
But the question posed is a good one. Does the vodka really add much to the sauce? Doesn't the alcohol all simmer off? Is it all just a ploy by the vodka manufacturers to get us to buy more of their hooch?
Harold McGee has a bit to say on the subject in his On Food and Cooking (get it NOW if you don't already own it). Check this out:
"The alcohol molecule bears some resemblance to a sugar molecule, and indeed it has a slightly sweet taste. At high concentrations, those typical of distilled spirits and even some strong wines, alcohol is irritating, and produces a pungent, "hot" sensation in the mouth, as well as in the nose. Its chemical compatibility with other aroma compounds means that concentrated alcohol tends to bind aromas in foods and drinks and inhibit their release into the air."
Huh. I stopped reading when I got to that part and started scratching my head, because I know from past experience that adding alcohol to stews will increase their aroma. I tested it out in my Best Chili Ever recipe. What's he on about, inhibiting aromas?
But he quickly clears it all up:
"But at very low concentrations, around 1% or less, alcohol actually enhances the release of fruity esters and other aroma molecules into the air."
A-ha! Now it makes sense: concentration is an important factor when it comes to its effectiveness as a flavor enhancer. This jibes with my past experience. Adding a bit of alcohol at the end of cooking is a good idea for stews and chilis, but too much and the booziness can become overpowering, leaving you smelling nothing but the alcohol instead of the better aromas its supposed to be carrying. Whiskey drinkers can tell you that diluting a dram from 40% ABV (Alcohol % by Volume) down to 30% or 20% ABV will also bring out aromatics that are otherwise hidden.
So does the same really happen to pasta with vodka sauce?
For one set of batches I added varying degrees of vodka, diluting the alcohol content to various levels starting at 4% ABV of the total sauce down to 1%, tasting the sauce immediately after adding the vodka.
For the other set of batches, I did the same thing, but instead allowed the sauce to simmer for seven minutes after adding the vodka and before tasting.
Of the batches in which sauce was tasted immediately after adding the vodka, none were great. 4% was downright inedible, with a strong, alcoholic aroma and bitter flavor. I'm not exactly sure where the bitterness was coming from. Perhaps by masking the fruitier, sweeter aroma of the tomatoes, their bitterness was coming out more strongly?
In any case, only when I got down to 2% ABV did the sauce become bearable. I very slightly preferred the 1% sauce over the completely alcohol-free sauce. But just barely.
Cooking the sauce made a huge difference. After a seven minute simmer, even the 4% sauce became bearable, though the bright sweetness of the tomatoes didn't really start showing until I got back down to the 2% sauce (which, after simmering for a few minutes, must have settled down to closer to 1% in the end). The harsher flavors of the vodka dissipated, the bitterness was gone, and I was left with a nicely balanced sauce that packed a little bit more heat and bright aroma than the completely vodka-free sauce.
So to answer the question: yes! Vodka does alter the flavor of the sauce in a pleasing way. It adds a touch of heat and a bit of a sharp bite that help balance out the sweetness of the tomatoes and the cream. Is it absolutely necessary? No, but vodka sauce just wouldn't be, well, vodka sauce without it.
To get a vodka sauce with a 2% ABV before simmering, you'll need to add 5% of the volume of the sauce in 80-proof vodka. That breaks down to just under 1/4 cup per quart.
I also wondered about the question of leftovers. Does reheating the sauce end up eliminating too much vodka? I let a batch of my winning 2% ABV, seven-minute cooked sauce cool completely, then reheated it and divided it in two. One side I tasted as-is, while to the other side I added extra vodka and re-simmered it. The one with an extra 2 teaspoons of vodka per cup of sauce (about 2 1/2 tablespoons per quart) was the winner.
TL/DR version: For the tastiest vodka sauce, add 1/4 cup vodka per quart of sauce and let it simmer seven minutes. If you've got leftovers, just make sure you stir in an additional 2 teaspoons vodka per cup of sauce and let it simmer for a few minutes before serving again.