[kaybe]

That is a new idea, thanks! I was suspecting pesticides or similar, since my allergy is highly batch-dependant and there have been less and less occurrences over time.

[taeric]

I stress that I may have made up the article I'm referencing!

I ultimately take "allergy" to mean, "we don't fully understand the reason."

[kaybe]

Regardless, it's an interesting theory that I hadn't considered before. It's harder to imagine how that would work, but not inconceivable.