Two of my last Irish Red Ale brews have fermented vigorously but without any foam. The first one finished fermenting in 24 hours, and the carboy had a lot of swirling and upwelling action going on. It almost looked like it was boiling, but the temperature was 67 F. I decided I must have pitched too much yeast and that all of the motion essentially stirred all the foam back into the liquid. The beer tasted fine, so there was no infection or contamination. I did several more brews that went normally, then I tried the Irish Red Ale again. This time I made a much smaller starter. When I shook the carboy to aerate the wort I noticed that it did not get a thick foam cap on it as I am used to seeing. This time the fermentation was slower, and there was a bit of foam, but again no thick krausen layer. There was a bit of the brown gooey stuff that forms on top of the krausen and then gets pushed to the edges. The beer tastes fine, so there is no infection or contamination.
The one thing that these two brews have in common that is different than the others is that I used Malting Co. of Ireland Ale Malt for the base malt (8-9 lbs out of 12 total). This malt is supposedly very low in protein, and I wonder if that can be causing the lack of foam. I used WLP004 Irish Ale Yeast, but I have used that yeast before and had no strange behavior, even with this same recipe with a different base malt. Has anyone else had this issue? Has anyone else used this base malt? Any other ideas?