Recent drop in efficiency...what could it be?

[KyleWolf]

Hey everyone,

Recently (In the last 7-8 batches) I have noticed a significant drop in my efficiency. I normally hit 75% without a problem. I haven't changed anything in how I brew, I go through the same steps I always do. Could it be my base grain is losing enzymatic power? (my homebrew group does bulk buys so I buy in 50lb sacks). My volume doesn't appear to be off, so I don't think that is it, but I don't keep as close an eye on it as I should, I just know it isn't so far off it is noticeable. Besides reasonably new sacks of grain (a 50lb bag of pilsner and 2row), the only other thing that is new is my hydrometer. I measured it at baseline water and with a sucrose solution (1.000 and 1.061 respectively) and both were accurate. Does anyone have any suggestions or thoughts as to why my efficiency suddenly started dropping?

If you need anymore info, I would be glad to give it.

Thanks
Kyle

PS. 5 of these batches are in primary and secondary as we speak. So when it comes time for kegging, I guess I will find out if my volume is way off lol. Atleast then it will be an easy answer to the question.

 

[cootball]

Another instrument to check is your thermometer. I use three.

 

[phenry]

How is your grain crushed? That's probably the first place I would look.

 

[thegerm]

I heard today on an old brewstrong episode on milling with a guest from briess that stored grain can take up to 10% extra mass in water from a humid environment. So pound per pound that could cause a drop in efficiency.

 

[KyleWolf]

Cootball, you have a good point, my thermometer could be bad, like you though, I use two, a regular meat thermometer and a digital. (I know the regular thermometer is atleast accurate at boiling)

My grain is crushed with a friends barley crusher, which I have always used. Unless he reset the crush, I wouldn't have thought it was the problem, but it is something I am considering.

thegerm, I have never heard that before, but it sounds interesting. I will have to go back and listen to that particular episode.

Thanks for the suggestions so far.