So I recently tried buying ingredients from a different supplier than I've used in the past. I did this for a new recipe and was unhappy with the results - the beer lacked body and head. But there were a lot of things new to me on that: a new recipe, a new supplier, and I used Danstar Nottingham yeast for the first time.
I then brewed a simple recipe that I brew fairly often (3 gallons: 3 pounds DME, .5 lbs 40L Crystal, .5 lbs flaked barley, Hallertauand Amarillo), again my ingredients came from this new supplier and I again used Danstar Nottingham, and again the result lacked body and head. in the past I've used SafAle American Ale yeast.
My question is do you think the problem is more likely caused by the yeast difference or perhaps the quality of the ingredients from the supplier? I suspect that it is due to the high AA of Nottingham.