Kheng guan Toh
The question
I love wine but get migraines from even small amounts of sugar. Is there a way to tell which styles have less sugar than others?
The answer
It's tough to generalize because sugar content is to a large extent under the control of the each producer, and it can vary significantly even for the same grape grown in the same region.
Your question is interesting because it's not the typical "I don't like the taste of sweet wines" complaint. You appear to be concerned with actual sugar content versus perceived sweetness. There's a significant difference. Sugar in wine (often referred to as "residual sugar" because it represents the level of grape sweetness that was not mopped up by yeast during fermentation) is measured in grams per litre. All wines contain at least some residual sugar, but 2 g/l is pretty much scraping at the floor of very dry.
In terms of perceived sweetness, red wines typically considered "dry" can span all the way up to about 10 g/l, while for whites that upper limit can go higher, perhaps up to 15 g/l. (These limits are subjective; it all depends on your personal taste judgment.) How does a 15 g/l wine manage to taste dry to some people? It largely depends on the presence of acidity and/or astringency. Acid in particular balances sweetness, causing wine to appear less sugary than it is.
Bearing in mind the aforementioned caveat regarding generalizations, you could do worse than to begin focusing on: Beaujolais, Bordeaux, Chianti, Rioja, Muscadet and sauvignon blanc. Avoid riesling in particular because even those labelled "dry" can push beyond the already high, 16 g/l level (although Australian rieslings tend to represent something of a truly dry exception).
The best tool at your disposal, particularly if you live in Ontario, is the Liquor Control Board of Ontario's website, lcbo.com. To my knowledge, Ontario is the only jurisdiction in the world that measures and records residual sugar for every wine sold through its channels. You'll find the actual sugar content in g/l (versus the old-school perceived-sweetness numbers) listed on that site for most wines sold in its retail stores. Alberta provides similar grams-per-litre data on the Liquor Connect website (liquorconnect.com), but the numbers are provided by winery agents and can be at odds with those measured at the LCBO laboratory. For example, the Prisoner, a California red blend, weighs in at 5 g/l according to the LCBO, while it's listed at just 1.2 grams on Liquor Connect.
E-mail your wine and spirits questions to Beppi Crosariol. Look for answers to select questions to appear in the Wine & Spirits newsletter and on The Globe and Mail website.