Drastically missed target OG

[jonpecan]

I brewed a BIAB last weekend. First off, I know it could have been any one of many things that resulted in a very unexpectedly low OG, especially with my brew day (it was my 3rd of three brews in a row... while one mashed, the other would boil... a little chaotic).

But no matter how crazy a brew day gets, I've never missed OG so dramatically.

So here's what I did, and maybe someone can see a fatal flaw I may have overlooked! It probably has more to do with a problem with how I mashed without me realizing it, but curious if someone can see something I'm missing.

Expected OG: 1.046
Actual OG: 1.034

5 lbs Vienna
5 lbs Rahr Red Wheat
1 lbs Cara-Pils
1.00 oz EKG 60.0 min
1.00 oz EKG 10.0 min

BIAB, 4 gallons of mash water. Mashed for probably over an hour at 140-145, raised it to 155ish. Removed bag, squeezed a bit, rinsed with 2-3 gallons cold sparge water. Boiled for 60, ended up with about 5 to 5.5 gallons.

Could the Rahr Red Wheat be a culprit? I was concerned when purchasing it - seemed like it was wheat malt, but the name was just "red wheat". I'm pretty sure it's malted, but I'm not 100%. When I remove the wheat from the recipe in beersmith, it is pretty close to the OG I got (beersmith estimated 1.029 - and the difference could account for inaccurate volume calcs).

Also, in the past by BIABs i've just used the entire amount of boil water in the mash. I've only separated the amounts for mashing and for sparging once or twice.

Any thoughts appreciated. It's also possible I missed my mash temps, fell too low in parts of the mash (my thermometer does not have a long stem).

Thanks!

 

[smakudwn]

That mash temp seems really low to me. Maybe you didn't get full conversion?

 

[C-Rider]

BeerSmith says of w/just the 10 lbs should be about 58. But I could be off not using the same equipment set up.
Northern Brewer says this about your wheat---> This American wheat malt is made from hard red winter wheat and has a slightly fuller, richer taste than normal wheat malt. So it is malted.
How was your crush? Did you do it? Did you double crush?

 

[Owly055]

That mash temp seems really low to me. Maybe you didn't get full conversion?

I would agree with this. Conversion is very slow at those temp ranges, and only the beta amylase is at work. Beta cannot do a full conversion by itself. You need to mash higher where both apha and beta can work together. If you'd held it around 155 for a few minutes as you were reheating, the alpha can work pretty fast and your gravity would shoot up rapidly, though for optimum fermentability you need to mash in the 150ish range.

Also sparging with cold water seems not the greatest idea (to me). There really is not a lot to be gained by mashing at a high density in BIAB then sparging. I do get better efficiency if I retain some water and sparge, but 50% plus seems excessive. I'm not sure cold water will wash the sugars out as well as hot water......... I suspect NOT.


H.W.

 

[RM-MN]

If it didn't say Red Wheat Malt on it I think you got red wheat. That would work out fine if you used pale malt with it as that has sufficient excess enzymes to convert unmalted wheat but Vienna has barely enough to convert itself. That would account for the low OG. It should also leave you with starch haze. It should also give great heading on your session ale.

 

[jonpecan]

That mash temp seems really low to me. Maybe you didn't get full conversion?

I'm thinking this may be it.

BeerSmith says of w/just the 10 lbs should be about 58. But I could be off not using the same equipment set up.
Northern Brewer says this about your wheat---> This American wheat malt is made from hard red winter wheat and has a slightly fuller, richer taste than normal wheat malt. So it is malted.
How was your crush? Did you do it? Did you double crush?

Single crush, but it's a fine crush I get with my cereal killer.

I would agree with this. Conversion is very slow at those temp ranges, and only the beta amylase is at work. Beta cannot do a full conversion by itself. You need to mash higher where both apha and beta can work together. If you'd held it around 155 for a few minutes as you were reheating, the alpha can work pretty fast and your gravity would shoot up rapidly, though for optimum fermentability you need to mash in the 150ish range.

Also sparging with cold water seems not the greatest idea (to me). There really is not a lot to be gained by mashing at a high density in BIAB then sparging. I do get better efficiency if I retain some water and sparge, but 50% plus seems excessive. I'm not sure cold water will wash the sugars out as well as hot water......... I suspect NOT.


H.W.

I think I may have not kept the alpha time above 155 long enough.

If it didn't say Red Wheat Malt on it I think you got red wheat. That would work out fine if you used pale malt with it as that has sufficient excess enzymes to convert unmalted wheat but Vienna has barely enough to convert itself. That would account for the low OG. It should also leave you with starch haze. It should also give great heading on your session ale.

This is still part of my fear, but I am leaning towards my mash temps as culprit - but the issue of malt vs. non-malt even bothered me while ordering - i thought it looked okay. I think this probably isn't the issue, I should just ask the merchant what the product is.

And though it is a bit of a waste of malt potential, I am pretty keen on this being a session wheat!

Thanks for all the replies folks!

 

[RM-MN]

I'm thinking this may be it.



Single crush, but it's a fine crush I get with my cereal killer.



I think I may have not kept the alpha time above 155 long enough.



This is still part of my fear, but I am leaning towards my mash temps as culprit - but the issue of malt vs. non-malt even bothered me while ordering - i thought it looked okay. I think this probably isn't the issue, I should just ask the merchant what the product is.

And though it is a bit of a waste of malt potential, I am pretty keen on this being a session wheat!

Thanks for all the replies folks!

How fine can you crush the wheat? Make a very small test batch with just the wheat. Crush up a pound of it. (maybe less even) heat a half gallon of water to 160. Drop your mesh bag in and stir in the wheat. It should be cloudy from the starch. Cover and wait 10 minutes. Open it up and look again. If it converted, the wort should be pretty clear. Taste it. It should taste sweet. Take a hydrometer sample. Those quick tests will tell you for sure what you have.

 

[jonpecan]

How fine can you crush the wheat? Make a very small test batch with just the wheat. Crush up a pound of it. (maybe less even) heat a half gallon of water to 160. Drop your mesh bag in and stir in the wheat. It should be cloudy from the starch. Cover and wait 10 minutes. Open it up and look again. If it converted, the wort should be pretty clear. Taste it. It should taste sweet. Take a hydrometer sample. Those quick tests will tell you for sure what you have.

Brilliant. Maybe I'll skimp and do a half pound!

 

[RM-MN]

The actual amount won't matter much. The milling and the temperature are more important. You should know the answer in about 20 minutes.

 

[C-Rider]

I think this probably isn't the issue, I should just ask the merchant what the product is.

If it is Rahr Red Wheat as you stated then it is a malted grain.

 

[jonpecan]

Thanks for the confirmation

 

[doug293cz]

The cold water sparge was not the cause of the low efficiency. http://braukaiser.com/blog/blog/2009/05/12/cold-water-sparging/

Brew on

 

[jonpecan]

The cold water sparge was not the cause of the low efficiency. http://braukaiser.com/blog/blog/2009/05/12/cold-water-sparging/

Brew on

Indeed, I have been cold sparging since starting BIAB - it's been a great relief, and I've perceived no loss of quality or efficiency.

 

[jonpecan]

I happened to have time to brew again today, and I had the exact same grains available to replicate the recipe.

99% likely it was the mash temp causing my problems the first time. Today, I kept the mast at 155 for much longer, and raised to 165 before removing the bag. OG jumped to 1.059 (had a slightly lower final volume - but the aim for 5 gallons was about 1.055).

To summarize my findings:

Rahr Red Wheat is malted!
Make sure your wheat malt (or Vienna?) gets good time at 155!
Cold sparging is fun and easy!
Brewing one beer at a time is safe, but lame!