Wyeast 1098 British Ale

Wyeast 1098 British Ale-- first time using this (I've always used the 1968 London ESB Wyeast).

A few days into fermentation and it's bubbling away like normal-- but has the smallest head of krausen I've ever seen.

Temperatures at 66*F, right in the target 64 - 72 range for this yeast. Perhaps this is more indicative of the low alcohol content (3.7% ABV), but I feel like I've made other low alcohol batches with better-looking results.

Any knowledge is appreciated! Thanks!

(Note: This is not one of those "should I dump the batch" threads, I'm just curious about the specific yeast.)

I personally have noted a HUGE difference in kraeusen thickness between batches (even identical recipe batches) that I fermented at 65 and at 68. Those few degrees seem to make a huge difference in yeast activity.

Specifically, I'm thinking about two batches of my IPA. The 65F batch had only about 1/2 to 3/4 inch of kraeusen. The 68F batch had about 4 inches and made we worried that I was going to have my first ever blow-out. Recipe was 99% identical.

-walker