Before I get back to posting more techy-stuff about sulphites in wine, here’s a brief diversion into the question of whether sulphites in wine can cause headaches.
Two things are clear. One is that, as far as I know, there is no scientific evidence that they do – we know that sulphites may result in a number of various symptoms in a small section of the population, but headaches is not one of them. The second is, despite that, quite a few people do believe that sulphites cause headaches, and have anecdotal evidence to support their belief. And of course a lack of scientific evidence for a proposition does not mean it is wrong.
The main problem with the anecdotal evidence is that wine contains another chemical, one that we know for sure causes headaches: alcohol. And there are also other chemicals that could conceivably do the same. So if you suffer from wine-related headaches how might you attempt to identify what is the culprit?
An easy first step would be to establish which wines are more likely to give you the worst headaches. Are sweet ones the worst? Followed by dry whites, and with red wines least likely to give you headaches? If so, that pattern is consistent with sulphites being to blame, because sweet wines are likely to contain more sulphites than dry ones, and white wines more than reds. On the other hand, if red wines are the worst, then it is more likely to be due to a chemical extracted from grape skins. A possible culprit is histamine – you could test for that by seeing if an antihistamine helps (but do check first that it is OK to consume alcohol with the drug). Or of course red wines might be giving you more headaches simply because they tend to contain more alcohol.
You could also compare your normal wines with ones that have particularly low sulphite levels. Generally speaking, a better quality wine, or something natural, biodynamic or natural, will be likely to have lower sulphite levels. But to be sure that you are comparing with a low sulphite wine you could go to the Raw Wine website and search for wines with levels under, say, 20 ppm. If lower sulphite wines give you fewer headaches it may still not be the sulphites themselves that are making the difference, as wines with low sulphite levels are probably low on other additives too. But on the other hand, if you like the low sulphite wine you might consider your problem solved anyway, so who cares?
Another approach would be to note if other sulphite-containing food and drink gives you headaches. Bright orange dried apricots are said to contain up to 1,000 ppm of sulphites. That’s a lot more than would be allowed in any wine, though to be fair you are likely to consume more wine in one session than apricots. Here’s a list I found of food and drink containing more than 100 ppm sulphites:
Dried fruits (excluding dark raisins and prunes)
Bottled lemon juice (non-frozen)
Bottled lime juice (non-frozen)
Sauerkraut (and its juice)
Grape juices (white, white sparkling, pink sparkling, red sparkling)
Pickled cocktail onions
I feel a bit ill reading that list, but if you can pig-out on dried apricots, molasses, sauerkraut (and its juice) and pickled onions without getting a headache, probably sulphites are not responsible for your hangovers.
All the above suggestions are as unscientific as any assertion that sulphites cause headaches. The best they can achieve is to give you a little more understanding of how you personally react to sulphite additives, and I’m afraid that’s the best I can offer.