I went ahead and tasted my cum today (I was about to wipe it off my hand and figured "why not?").
The taste was boring, like egg whites. Appropriately enough, the consistency also reminded me of egg whites.
What surprised me was the reaction I had afterward. The part of my tongue I'd licked my cum with started hurting a little, as if it was drying out or had been burnt. On the advice of a friend, I used some Listerine to rinse it off. Curiously, the part of my tongue that hurt really hurt once the mouthwash started doing its job.
Combined with my previous experiences with skin reactions against my cum when it gets on the backside of my hands, I wonder if I have some kind of allergy. Because self-diagnosis is generally stupid, I'll ask the doctor the next time I go to take my STD tests.