Wildly different efficiencies.

[Fingers]

So I broke my brewing fast this weekend by doing two ten gallon batches. I did 10 gallons of ale on Friday and ten gallons of lager today. For the ale batch my efficiency ran 62% and the lager ran 81%. My techniques were identical except for a longer boil on the lager. Volumes were about the same.

I do a triple batch sparge with 180 degree water. I crushed both batches with the same mill while the strike water was heating. The only real difference I can think of is that I the lager had grains bought from the HBS and the ale had a base malt that I bought from the malt plant last fall. The grain was stored in a plastic bin with an attached lid.

So. Could it be the base malt itself? The lager (Marzen) used mostly Vienna malt as a base and the ale used Canadian two row. I'm open to any other rational suggestions that may account for this.

 

[King of Cascade]

Did you hit your correct volume on both batches?

 

[Fingers]

Yes I did. I thought maybe I had an issue with channeling because I had a slightly stuck sparge on one of my sparges, but then I realized that it was on the higher efficiency brew. My temps were good both times as well.