Now there is no doubt in my mind that when shallots get old, their heat
increases tremendously! I cut up a shallot from the CSA package that I got
two weeks ago. When I first got them, they were mild and sweet. But this
one is killing me! I cut one up for salad a few days ago and it was much
hotter than when I first used them but this one is a total sinus cleanser.
OMG!

Alas, there is no way to tell by looking at them. I knew how old they were
because I knew when I got them. But it still looked perfectly fine. I
guess from now on I have to use them up within a few days of getting them.