I have noticed that whilst brewing a few Out of date kits(always add new yeast packets) that the foam head whilst fermenting is considerably less than th head from a new one.Is this normal?
Can't say that I've ever noticed any difference, I've had good yeast head on old kits and vice-versa. I think it has more to do with the type of kit you make - the darker and heavier beers seem to go off like something from Quatermass.