I MADE my first rice wines last week, and they weren’t nearly as bad as I expected. I didn’t attempt homebrew versions of Chinese jiu or Japanese sake. My rice wines were a storebought sauvignon blanc and a chenin blanc into which I threw some rice. I don’t think grain-infused wine will ever catch on as an alternative to a kir or sangria (though these days you never know). But I was relieved that it didn’t remind me of Billy Goodman’s pet mice.
Wines sometimes do smell like my grade-school pal’s mouse cage, and this is not a good thing.
The new third edition of the indispensable “Oxford Companion to Wine” notes in its entry for “mousy” that once this aroma is detected, it “renders the wine undrinkable.” Its elusive causes — no actual rodents are involved — have been under investigation for more than a century. Australian scientists at the Universities of Adelaide and Newcastle recently summarized the current state of knowledge, and it was their eye-catching “Mousy Off-Flavor: A Review” that led me from wine and mice to rice.
Mousy off-flavor was defined early on as “a peculiarly disagreeable flavor in wine” that closely resembles “the smell of a residence of mice.” Peculiar it is. You can’t detect it simply by sniffing the glass, or even by sipping the wine, at least not at first. It develops slowly, even after you’ve swallowed, and persists in the mouth for as long as 10 minutes. At least one of the responsible chemicals remains tightly water-bound in the acid conditions of wine, and so can’t escape into the air and reach the smell receptors in the nose. Then when the wine comes into contact with the alkaline surfaces of the tongue and palate and its acidity declines, the mousy-smelling chemical is freed to fly into the air and offend.
Many suspected perpetrators have been fingered over the decades, but modern research points to a trio of chemicals generated by several microbes found in wineries. One microbe is the barrel-colonizing yeast Brettanomyces, which is known to contribute funky aromas often likened to saddles, sweat and the barnyard. Some wine lovers consider any trace of “brett” aroma a defect, while for others it adds an appealing complexity.
Also strongly implicated in mousiness are lactic acid bacteria, including at least one strain that winemakers add intentionally when they want to carry out malolactic fermentation. So wineries should be able to prevent mousy off-flavor by choosing their malolactic cultures carefully, and by controlling Brettanomyces growth in barrels and other equipment.
The chemical suspects generated by these microbes are two compounds called pyridines and another called 2-acetylpyrroline, the strongest-smelling of the three. This last one surprised me because it was an old acquaintance, an admirable compound that I would never have thought capable of causing trouble. I think of it as the basmati molecule. It’s the chemical whose aroma distinguishes Himalayan basmati rices, Thai jasmine rice and other aromatic rices from all the rest. The name “basmati” comes from the Urdu for “fragrant,” not “mousy.”
The same molecule is generated from the amino acid proline during cooking, and makes a positive, toasty contribution to the flavors of popcorn, bread and many other foods. You can create it yourself by buying some proline from a health-food store, mixing the contents of a capsule in a small bowl with a similar portion of sugar and a spoonful of water, and then microwaving the bowl for 10 seconds at a time, sniffing after each zap. The basmati note develops as the solution gets thick and sticky, then disappears when it turns brown.
Can an aroma so good in food really turn so bad in wine? That was the question I tried to answer by making rice wines. The rice was the aged grade of the Kohinoor brand. For geographic appropriateness, the wines were a dry sauvignon blanc and an off-dry chenin blanc from the Sula winery near Mumbai.
I soaked a couple of spoonfuls of rice in a cup of each wine for four hours, then compared the infused wines with the originals. The rice versions tasted different, but not at all in the direction of my friend Billy’s mouse cage. The dry wine lost some of its edge and length, while the chenin blanc seemed richer, less simply sweet. So maybe the basmati molecule needs more time to go bad, or maybe it only gets that way when it hangs out with the wrong chemical company, the pyridines.
After this crude and inconclusive experiment, I went ahead with the obvious test. I cooked some of the basmati rice and had it along with the wines, alert to any hint of the cage as I ate and drank. Childhood stayed put. The combination of basmati and wine may be a problem in the winery, but it works fine at the table.
Mousy off-flavor was defined early on as “a peculiarly disagreeable flavor in wine” that closely resembles “the smell of a residence of mice.” Peculiar it is. You can’t detect it simply by sniffing the glass, or even by sipping the wine, at least not at first. It develops slowly, even after you’ve swallowed, and persists in the mouth for as long as 10 minutes. At least one of the responsible chemicals remains tightly water-bound in the acid conditions of wine, and so can’t escape into the air and reach the smell receptors in the nose. Then when the wine comes into contact with the alkaline surfaces of the tongue and palate and its acidity declines, the mousy-smelling chemical is freed to fly into the air and offend.
Many suspected perpetrators have been fingered over the decades, but modern research points to a trio of chemicals generated by several microbes found in wineries. One microbe is the barrel-colonizing yeast Brettanomyces, which is known to contribute funky aromas often likened to saddles, sweat and the barnyard. Some wine lovers consider any trace of “brett” aroma a defect, while for others it adds an appealing complexity.
Also strongly implicated in mousiness are lactic acid bacteria, including at least one strain that winemakers add intentionally when they want to carry out malolactic fermentation. So wineries should be able to prevent mousy off-flavor by choosing their malolactic cultures carefully, and by controlling Brettanomyces growth in barrels and other equipment.
The chemical suspects generated by these microbes are two compounds called pyridines and another called 2-acetylpyrroline, the strongest-smelling of the three. This last one surprised me because it was an old acquaintance, an admirable compound that I would never have thought capable of causing trouble. I think of it as the basmati molecule. It’s the chemical whose aroma distinguishes Himalayan basmati rices, Thai jasmine rice and other aromatic rices from all the rest. The name “basmati” comes from the Urdu for “fragrant,” not “mousy.”
The same molecule is generated from the amino acid proline during cooking, and makes a positive, toasty contribution to the flavors of popcorn, bread and many other foods. You can create it yourself by buying some proline from a health-food store, mixing the contents of a capsule in a small bowl with a similar portion of sugar and a spoonful of water, and then microwaving the bowl for 10 seconds at a time, sniffing after each zap. The basmati note develops as the solution gets thick and sticky, then disappears when it turns brown.
Can an aroma so good in food really turn so bad in wine? That was the question I tried to answer by making rice wines. The rice was the aged grade of the Kohinoor brand. For geographic appropriateness, the wines were a dry sauvignon blanc and an off-dry chenin blanc from the Sula winery near Mumbai.
I soaked a couple of spoonfuls of rice in a cup of each wine for four hours, then compared the infused wines with the originals. The rice versions tasted different, but not at all in the direction of my friend Billy’s mouse cage. The dry wine lost some of its edge and length, while the chenin blanc seemed richer, less simply sweet. So maybe the basmati molecule needs more time to go bad, or maybe it only gets that way when it hangs out with the wrong chemical company, the pyridines.
After this crude and inconclusive experiment, I went ahead with the obvious test. I cooked some of the basmati rice and had it along with the wines, alert to any hint of the cage as I ate and drank. Childhood stayed put. The combination of basmati and wine may be a problem in the winery, but it works fine at the table.
February 7, 2007
Copyright 2007 The New York Times Company
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