I've been noticing this same problem. I am not a big drinker, but when a nice pub opened in our small town, we started going there once a week to have a microbrew of some sort. Some of them give me absolutely terrible headaches that last 24 hours as described above. I usually order a half pint, that is one cup, of beer. Not a lot! And I don't feel the slightest bit tipsy. However, I have this awful headache. I wish I knew what was going on and what to avoid. For the record, red wine does not have this effect on me, nor do bottled brews from large breweries.
