OG consistently low

[Squad1Guy]

I have been brewing for a number of years and just switched to BIAB for the last four batches. I have consistently come in low on my OG for every batch. (My last was Denny Conn's porter that will be used in a Vanilla Bourbon Porter). I guess I have two questions...
What do you, my fellow Homebrewers, do to remedy this on brewday? I could just dump in some DME, but that kinda seems like "cheating" when doing all grain (to me anyway).
What in my process could cause this? My temp control during mash is good and I even try to increase my grain amounts to compensate for lower mash efficiency, but I am still pretty low. On the last batch I was shooting for a gravity of 1.077 and ended up at 1.067. This will give me a ABV of about 7% but I was expecting about 8.2% (according to Beersmith). Should I just increase my base malt to overshoot my intended gravity by 10 points and just run with it?

Comments and suggestions are appreciated.

 

[BigFloyd]

Have you calculated your efficiency?

Can you give us some more info on your grain crush? My LHBS owner lets me narrow the gap on his monster mill to .033 for my recirculating E-BAIB grain orders. I get a pretty consistent 75% efficiency.

 

[Squad1Guy]

Have you calculated your efficiency?

Can you give us some more info on your grain crush? My LHBS owner lets me narrow the gap on his monster mill to .033 for my recirculating E-BAIB grain orders. I get a pretty consistent 75% efficiency.

Crush might be a good part of the issue. It was set at the regular LHBS setting and I don't know what that is. I can't seem to make myself dump a container of flour into my mash vessel

BS calculates my efficiency around 65% so that is the number I base my recipes off of. Mash efficiency is usually over 80%. I even did a 75 minute mash this time to try to help overcome this problem.

 

[MMJfan]

Do you double crush the grains?

As far as flour goes, I have a corona mill and I've found that the finer my crush is, ie, the tighter I have the mill set at, the better my efficiency is and I attain OG's of what I'm shooting for...

 

[vNmd]

I get my grains from AHS. I ask for a fine crush but I am not sure if they do any different. There is a range of grains that look just cracked in half all the way to powder in each order and I usually get a few points over what their recipe says I should get.
Some common sense things I hate to even bring up, how close to the mash temp are you keeping it. I put a winter coat around my kettle and lose a few degrees per half hour. So half way through I stir and heat it a few minutes to get back to where I want it. I check my thermometer with another one to make sure the temp reading is fairly accurate. I pour the grain in kind of slow, stirring constantly to make sure there is no clumps that get stuck in a corner of the bag. I stir really well at beginning, half way through, and at the end as well as during the 10 minute mash out. It gets a good convection going in the kettle when I stir. I also squeeze grains pretty well <don't hate> after they drip for a half an hour. I have been hitting low 80's according to the calculators I use. I hope this helps.

 

[Squad1Guy]

I get my grains from AHS. I ask for a fine crush but I am not sure if they do any different. There is a range of grains that look just cracked in half all the way to powder in each order and I usually get a few points over what their recipe says I should get.
Some common sense things I hate to even bring up, how close to the mash temp are you keeping it. I put a winter coat around my kettle and lose a few degrees per half hour. So half way through I stir and heat it a few minutes to get back to where I want it. I check my thermometer with another one to make sure the temp reading is fairly accurate. I pour the grain in kind of slow, stirring constantly to make sure there is no clumps that get stuck in a corner of the bag. I stir really well at beginning, half way through, and at the end as well as during the 10 minute mash out. It gets a good convection going in the kettle when I stir. I also squeeze grains pretty well <don't hate> after they drip for a half an hour. I have been hitting low 80's according to the calculators I use. I hope this helps.

My crush might be the culprit.

My mash temps were pretty spot on. I was shooting for 150. I stirred the mash two times during the 75 minutes....once at 25 minutes in and once at 50 minutes in. At the stir my temps were 151 and 152 respectively. The only temp issue I did have was that it came in a little low (about 145) when I doughed-in....I got it up to temp in less than 5 minutes so I don't think that was an issue. There were definitely no dough balls when I mashed in my grain. I also squeezed the bejesus out of it after sparging (I did 2 sparges of roughly equal volume..."dunk sparge")
The thermometer calibration was checked when I got it and was spot on, but a recheck wouldn't hurt.
BeerSmith estimated my mash efficiency at 93.6 and an online calculator I used put mine at right around 82%. Could a 10% difference in the setting in BS and the actual efficiency have caused a 10 point drop?

 

[Squad1Guy]

Do you double crush the grains?

As far as flour goes, I have a corona mill and I've found that the finer my crush is, ie, the tighter I have the mill set at, the better my efficiency is and I attain OG's of what I'm shooting for...

I kicked around double crushing the grains, but I was afraid of adding a bunch of flour to the mash vessel. I think I will have to give double-crushing a try.