The pairing logic, in depth
Spicy food and wine have a reputation for not getting along, and the reason is a specific, avoidable chemical clash. Capsaicin - the compound that makes chili hot - is intensified by alcohol and by tannin. So the instinct to reach for a big, bold red with a fiery curry is exactly backwards: the high alcohol fans the burn, the tannin turns bitter and aggressive, and the fruit gets blown out. The meal wins and the wine loses.
The fix is to flip every variable. Lower the alcohol, drop the tannin to nothing, and add a touch of sweetness. Sugar is the single most effective tool against chili heat - it's why mango lassi cools an Indian meal and why a faintly sweet Riesling does the same job in a wine glass. Crucially, “off-dry” does not mean “sweet” on the palate: a good Riesling has so much acidity that the sugar reads as balance and coolness, not dessert. The acidity also keeps the wine refreshing, so it cleans up the richness of coconut milk or fried batter between bites.
Aromatic whites are the natural family here. Riesling is the all-star, but Gewürztraminer (lychee, rose, ginger) is uncanny with fragrant Indian and Thai spicing, and a dry-ish sparkling or a fruity rosé covers Mexican, Korean, and Sichuan heat. The common thread is perfume and freshness - wines that meet aromatic, spicy food on its own aromatic terms rather than trying to out-muscle it.
If you genuinely want a red with spice, it can be done, but choose carefully: a low-tannin, fruit-forward, moderate-alcohol red served slightly chilled - a juicy Zinfandel with smoky barbecue heat, or a chilled Gamay - has the ripe fruit to play along without the tannin and alcohol that make capsaicin worse. As a rule, the hotter the dish, the colder and sweeter the wine should lean, and the further you should stay from anything big and tannic.