Missed my OG with BIAB any suggestions?

[phil9tpa]

I was wondering if anyone had a suggestion as to why I missed my OG. According to Beersmith, it was supposed to be 1.075 and came in at 1.062. My water volumes were all right, and I stayed within my steep temp. of 156 the entire 75 min. Thanks for any help.

 

[adiochiro3]

Sounds like your efficiency was low for some reason. Most BIABers double/fine crush their grains.

1. Did you?
2. Did you sparge?
3. Are you sure your mash temp was correct? (Thermometer accuracy can be a problem.)
4. Was your gravity sample at the right temp? (If it's too warm, it will give you a low reading.)

With more info, one of us can help.

 

[dkennedy]

Sounds like your efficiency was low for some reason. Most BIABers double/fine crush their grains.

1. Did you?
2. Did you sparge?
3. Are you sure your mash temp was correct? (Thermometer accuracy can be a problem.)
4. Was your gravity sample at the right temp? (If it's too warm, it will give you a low reading.)

With more info, one of us can help.

+1 on these points. I'm breaking in a new setup, and have identified that my mill needs to be tightened up a bit, and that whoever hung a vent fan right above the kettle needs to be smacked (no idea who did that...nope) and I need to get enough vertical clearance to be able to effectively drain/sparge/squeeze.

 

[RM-MN]

+1 on these points. I'm breaking in a new setup, and have identified that my mill needs to be tightened up a bit, and that whoever hung a vent fan right above the kettle needs to be smacked (no idea who did that...nope) and I need to get enough vertical clearance to be able to effectively drain/sparge/squeeze.

Someone did that to me too (Uh, since I designed and built the house, I suppose I'm to blame but that was 30 years before I started brewing) so I use a plastic bowl with a colander inside it to drain and squeeze out the wort. I do have just enough room above the pot and beneath the vent to pour the wort out of the plastic bowl, even with the bag of grains and colander inside it.

 

[beng]

I've found what really helps to boost my efficiency is to omit one gallon of water from the initial mash, and then later when your mash hour is up, pour the gallon over the grain bag after it's lifted from the mash kettle. Makes for an easy, helpful sparge.

That and getting a nice fine crush, and squeezing the bajeebus out of the bag when mash complete.

I regularly get 75-80% eff.

Good luck.

 

[phil9tpa]

Sounds like your efficiency was low for some reason. Most BIABers double/fine crush their grains.

1. Did you?
2. Did you sparge?
3. Are you sure your mash temp was correct? (Thermometer accuracy can be a problem.)
4. Was your gravity sample at the right temp? (If it's too warm, it will give you a low reading.)

With more info, one of us can help.

Thanks for the feedback.

No, I didn't sparge. I just squeezed the bag really well (or at least I thought I did).

My thermometer is pretty accurate so I asumed i stayed within Mash temp.

I checked my gravity after the wort was cooled to 67 degrees.

 

[phil9tpa]

I've found what really helps to boost my efficiency is to omit one gallon of water from the initial mash, and then later when your mash hour is up, pour the gallon over the grain bag after it's lifted from the mash kettle. Makes for an easy, helpful sparge.

That and getting a nice fine crush, and squeezing the bajeebus out of the bag when mash complete.

I regularly get 75-80% eff.

Good luck.

Thanks! My water level was really high. I only had about a 1/2 inch of head space at the top of the 8gal kettle.

 

[adiochiro3]

Thanks for the feedback.

No, I didn't sparge. I just squeezed the bag really well (or at least I thought I did).

My thermometer is pretty accurate so I asumed i stayed within Mash temp.

I checked my gravity after the wort was cooled to 67 degrees.

All of those processes sound OK. I do a no-sparge BIAB with 80% efficiency (squeeze the heck out of the bag like you). You didn't mention grain crush. And I also realized I did not ask how thick/thin your mash was.

 

[seefish]

A no sparge BIAB should be a pretty thin mash, so I wouldn't worry about that. I normally stir my mash several times while mashing as well as using a finer crush on the grain. On recommendation from my LHBS, I just started using Amylase Enzyme in the mash to squeeze out a few more points of efficiency.

That being said, BIAB is going to be a lower efficiency in general. Not sure what efficiency you were shooting for but I wouldn't be too worried about something around 70% or maybe even a little lower. You just have to adjust for that in your calculations.

 

[McKnuckle]

Also, if you don't evaporate as much water during the boil as you accounted for in your recipe to get the predicted OG, that can have a big effect on the actual OG. With minimal head space in the kettle as you say, perhaps it was the case that you couldn't sustain a really good rolling boil.

 

[lylo]

I can't believe all of the misinformation that is still going around about BIAB. You don't need and extra fine crush and you don't need to sparge in order to attain close to an 80% efficiency with BIAB! You only need to do it right.
The guys at http://biabrewer.info/search.php?search_id=unreadposts pioneered the method and fine tune it on a daily basis. BIAB is there focus and reason for being.
As a disclaimer, I no longer BIAB as I won a lottery and bought a Braumeister (My said I could I could), but I still use the forum regularly.

 

[chickypad]

Sorry if this was mentioned but I didn't see it, what was the expected efficiency and what did you actually get? Do you have a way to accurately measure volumes and did you actually hit the target end volume?