Old Grains Cause For Low Efficiency?

[Breck09]

Ordered my crushed grains from NB on August 3rd and did not get around to brewing until today and got really low efficiency. I hit 60% and was aiming for 75% as the grains were a pre-made kit from NB. Could the grains sitting for 2 weeks (although they were in a cool area and kept in the bag they came in for the whole time) be one of the leading reasons why I hit such low numbers? I haven't hit my gravity numbers since my first batch (on AG batch #5 now) and I am really starting to get frustrated with it. I am using a converted cooler as my mash tun with a stainless steel braid. When I clean out my grains there is always a little bit of liquid left in the cooler but not enough to compensate for 15% points. I am not thinking it was the crush that would have caused the numbers as the kit I did hit my numbers on was from NB as well. Although I guess maybe the crush this time might not been as good.

Just really wanting to figure this thing out. I am hitting my mash temps and I guess I am getting good conversion but haven't tested with an iodine test yet. Any help you can give or advice would be awesome. Thanks.

 

[Hex23]

Just curious what kit you bought. I have what sounds like a similar system to you - cooler with SS braid. I put my braided hose in a loop, but not sure that makes much difference. I had pretty consistenly been hitting only 65% all with grains from my LHBS. Then when I got an Oktoberfest kit and some grains for another beer from NB I suddenly hit 78 and 79 percent on those. I'm thinking it must be a difference in the crush. I assume NB has a pretty standard crush.

I can't imagine waiting two weeks would make much difference. I'm not even sure waiting months would matter. Another thing that I've have found can matter is mash time. I did hit 75% efficiency with my LHBS crushed grains once, but that was a 90 min mash and I normally do 60. I extended that mash because an iodine test at 60 min looked questionable.

 

[Breck09]

It was the American Wheat kit. The best efficiency I got was from their Sierra Madre kit. Since then I have been hitting low numbers. I am going to start doing an iodine test and see if I'm possibly not getting full conversion. One thing with this wheat kit was that with only 8# of grains I should have split the batch sparge into two. Not sure if that would have helped or not. Thinking about going to a copper manifold and see if that might help.

 

[waldoar15]

I doubt if the age of the grain had much to do with it. It could be the crush and you do have to account for the dead space in your MLT along with anything you leave behind in the BK, ect. Could be that your thermometer is off. Could be that your volumes are off.

Milling your own grains is one of the best ways to take a lot of the guess work and a big variable out of AG brewing.

Boil off rates matter too.

 

[Hex23]

It was the American Wheat kit. The best efficiency I got was from their Sierra Madre kit. Since then I have been hitting low numbers. I am going to start doing an iodine test and see if I'm possibly not getting full conversion. One thing with this wheat kit was that with only 8# of grains I should have split the batch sparge into two. Not sure if that would have helped or not. Thinking about going to a copper manifold and see if that might help.

Maybe the difference is in the use of wheat or its crush. I assume the base malts are the same between the two beers.

The iodine test is a good idea. I do it for every batch, and it did help spot an incomplete conversion on a couple of batches.

If you are committing to changing your manifold, maybe you should consider something entirely different, like the drilled dome style.

Good luck. I know low efficiency can be frustrating, but unpredictable efficiency is even worse. Might be a good idea in the meantime to keep some DME on-hand or be prepared dilute to target OG.

 

[hadabar]

Well I have a similar setup and get 75%-80%....

My best tip, slow down your sparging....like 30 min...huge help...thats if your fly sparging....batch sparging may be the culprit if thats your process

Btw...I've let grain sit twice as long and ironically out was my most efficient batch go figure