White foam in BK with rye malt?

I did my first batch with rye malt this past weekend.  During the boil, I noticed a small but persistent amount of bright white foam. I skimmed it off, but it kept reforming. It’s this a feature of rye malt? I’ve never noticed with any other batches (including one with identical ingredients except for wheat malt rather than the rye).

I use a lot of rye malt and I’ve never seen that.

I bottled it today. Everything looked normal. Good attenuation. Tasted fine. :man_shrugging: