First all-grain BIAB: IPA OG waaay too low

Hi all,

I decided to try out my new homemade BIAB setup with a 5 gal. batch of Deadringer IPA last week. The recipe called for an OG of 1.064 - but mine came out to 1.038. I took the reading at room temp (right before pitching yeast). I can post my setup as well as procedure... well here it is:

Setup:
10 gal aluminum pot
large voile bag that fits over pot and closes
thermometer in thermowell

Procedure:
heated 8 gal. of water to 155 and doughed-in
temp dropped to 150 so i heated back up to 152 for mash temp
mashed for 60 min with lid and blanket on
mashout to 170 for 10 min (later came to learn that this means hit 170 - then wait 10 min... i took 10 min to get to 170 oops )
pulled grain bag and squeezed hot bag as hard as i could
boiled for 60 min (added hops in small muslin bag)
cooled in ice-water bath and galvanized tub for 45-50 min.
took a reading at 68 deg. - 1.038
dumped into carboy and pitched dry yeast packet.
krausen peaked on 2nd day - now no more bubbles in airlock

So...
Where did I go wrong to get such a loooow OG?
Will I still get an OK IPA?
What can I do next time to improve?
Is it likely that I'll get a stuck fermentation?

Thanks in advance!

How was your crush?

Your crush is something to look at. A bad crush will hurt your efficiently in a big way.

Also, you might adjust up on the hydrometer reading a bit because many of them are calibrated for 60 degrees (but this isn't the source of your problem, obviously). There are lots of calculators that will show you the correct reading at a certain temperature.

I don't think you'll have a stuck fermentation, all things being equal. I don't see any problems with your setup or procedure. Lack of airlock/blowoff tube activity does not equal finished fermentation. The only way to know is to take successive hydrometer readings.

One more thought: did you make sure that the grain was well mixed and wet? If there were dry clumps, that might have hurt you.

It looks like your process is pretty close to mine so I cant see that as an issue. Zachattack hit the nail on the head I think. A fine crush is important for effiency when you use the BIAB technique. If you got the ingredients from the internet pre crushed or used your LHBS's mill you most likely didnt get a very fine crush. Most BIAB brewers will run their grain through the mill twice. The first purchase I made after going to BIAB was my own mill. For around $150 its the best investment into brewing hardware I have made yet. Also something to do before making your next batch would be to calibrate your thermometer in boiling water to make sure it reads 212F and ice water at 32F. Lastly the Mash PH can have an effect on your conversion, Read the Brewing water primer in the Brewing Science section and consider using RO water with the suggested salt additions.
At 1.038 you are really making a hoppy Pale ale.
As far at a stuck fermentation goes that is dependent on your yeast pitch rate and fermentation temps more then your OG.

Ha - that's a funny story actually. I think I was the first person to buy grains from my new LHBS. The owner held the mill in one arm and a bag in the other while i poured the grain in. We ripped the bag twice and had to add more grain. I wasn't about to ask about the crush setting on the mill - we were just lucky to get it done

That being said, seeing as this was my first all-grain I am no expert at determining how my crush was, but... it seemed to be a bit coarser than i would have expected. Some grains even seemed to be intact (not crushed)... oh well.

Yeah, if that was the case the crush is most certainly to blame. I would call up the store and let them you about your bad efficeny so that they can adjust the mill.

Good advice guys thanks. I will work on the grain crushing situation.

As far as my thermometer goes, I did calibrate it in boiling water and actually took into account my altitude here in VT which brought my boiling point to around 210 deg. F

Prymal: What is RO water? salt additions? I use town tap right now...

PistolsAtDawn: I mixed it once or twice but I was scared that uncovering it and mixing it would drop my mash temp out of range. Thoughts?

I dont know what water in Ludlow VT is like but if it overly hard you might find that pale beers dont turn our as good as you think they will. RO stands for Reverse Osmisis, its essentially super filtered water (very soft). If you go to a grocery store and they have a water dispencing unit where you can fill 5 gallon or 1 gallon jugs it is producing RO Water. The water that you use for brewing is just as important as the grain hops and yeast. If you are putting good water into your brew you will have a better chance of getting good beer out. The up & downside of using RO water is that since there are almost no minerals in it you need to add some back with the addition of Salts. I am still pretty new to building brewing water so i would suggest reading the Brewing Water Primer in the Brewing Science section to get a better idea of what I am talking about.

I tend to heat my strike water 7 degrees above my desired Rest Temp. This compensates for heat loss from adding the grain and mixing the hell out of it. I also open up my kettle and give it good stir about half way through the Mash. You shouldnt be too worried about loosing heat because if you have the ability to heat your mash up to 170 for a mash out you can do the same to raise to temp a few degrees if it drops out of your desired range.

Im an extract brewer, so I know nothing about your issues there, but I did see you ask about RO water, and I was a water purification specialist in the army for 8 years, so I can speak on that subject. Reverse Osmosis. Water is forced through a non-pourous filter at high pressure, breaking it down at the molecular level and removing any and all dissolved solids leaving you with pure H2O. That being said, I believe some mineral content in your water is good for brewing, though I'm not sure what additions you would have to make. Probably way more info than you wanted, but I'm currently 2 deep on my freshly ready 1.112 barley wine #drunk

Ohhh... I see... the "Stickies" have tons of info on brew water science - got it!

and It certainly will be hoppy as I'm dry hoppin' an ounce of Cascade on Friday when I rack to secondary :rockin:

I will look into the additions Inhoskins, thanks.

I will also plan on a higher dough-in temp next time (Prymal)... trial and error i guess.

Also, next time I will do a better job of calculating how much water I need at the beginning of this process. I ended up pouring 5.5 gal. of wort into my carboy when I only needed 5. So I guess I overestimated how much water i would boil-off and how much the grain would absorb. Now that I've done it once (and kept good notes) I can estimate more accurately next time. I'm sure that didn't help my OG either.

How tight was the grain packed in the bag. A friend of mine used a bag that was too small, and I think that caused essentially a single huge dough ball. He basically didn't mash a bunch of malt cause it was too-compacted in the bag.

Just something to think about.

What did your crushed grain look like? Just a hunch, bet sometimes stores sell most or all of their crushed grain intending it to be used for steeping in an extract batch, and the crush can be lacking. In the future make sure that all the grain pieces are crushed and well fractured.

The grain bag is pretty large. I mean I can fit the pot inside it... so i don't think it was restricted. I have a cheap wire rack false bottom to keep it from scorching.

The grain looked like almost whole 'kernels' with a piece of the 'shell' missing. Some of the 'insides' were still inside, some were out. I'm a bit inexperienced with all-grain to really give a good description but i think it was pretty coarsely ground.

The crushing was done to order - but i think i just need to ask them to make it finer next time.

chasman said:

Also, next time I will do a better job of calculating how much water I need at the beginning of this process. I ended up pouring 5.5 gal. of wort into my carboy when I only needed 5. So I guess I overestimated how much water i would boil-off and how much the grain would absorb. Now that I've done it once (and kept good notes) I can estimate more accurately next time. I'm sure that didn't help my OG either.

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This hurt your OG, though I think this isn't the main culprit.

mjohnson said:

How tight was the grain packed in the bag. A friend of mine used a bag that was too small, and I think that caused essentially a single huge dough ball. He basically didn't mash a bunch of malt cause it was too-compacted in the bag.

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This is what I was wondering about, but after reading your other replies, it's absolutely the crush that is to blame. You sounded like you mixed well enough.

Water additions are something to look at, but honestly, I'd hold off until you master some of the other bits of this, including protein rests. It's not like it's hard, but that wasn't your problem here. If your pH is too high in your mash (anything over 5.8 is bad), that can cause astringent flavors with pale malts. Usually darker malts will drop your mash pH, so this isn't as much of a concern. Definitely should be a step that you incorporate either as you start all-grain or shortly after.

By the way, an "ugly junk" Corona mill setup is cheap and easy and works just about as well as a much-more-expensive mill. There are instructions on this forum. Look for "ugly junk".

PistolsAtDawn said:

This hurt your OG, though I think this isn't the main culprit.

This is what I was wondering about, but after reading your other replies, it's absolutely the crush that is to blame. You sounded like you mixed well enough.

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That's what I'm gathering from all the comments too. Will work on it. Thanks.

I run my grain through the mill twice. It's DIY at the brewshop. Would suggest not being afraid to open the pot and stir. Also a longer mash time may help.
I stir it up every twenty minutes and usually mash for 70- 80.

OK - so i racked to secondary and dry hopped with an ounce of cascade today. The SG reading is at 1.003. Needless to say the beer is very watered down. Is there a way of adding something to fix this batch? Maybe some DME or something???

Hey, just a question for you, did you get this done at Brewfest? If so, I think that they must have just started crushing grain, which would explain why maybe their mill was off.

Also, I don't think there is much you can do about your beer at this point. What you might do is blend it with a strong ale or something along those lines to give it some body. Just another reason to brew...

Cheers from Rutvegas!

yup... i think you're right. I'll talk to them next time I go in about it. I told them to mount the mill to a piece of plywood with a hole in it and place that over a bucket. I guess there's not a huge demand for all-grain supplies around here.

And I don't think I'll bother blending it at this point. It will be my summer post-yard work refreshment! I'll get it right (or at least better) time.

Cheers! :rockin:

chasman said:

The grain looked like almost whole 'kernels' with a piece of the 'shell' missing.

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Not crushed enough IMO...heard someone say 1/3 flour, 1/3 pieces, and 1/3 husks....while this might be a heavy crush, it is far better than "almost" whole pieces.

chasman said:

OK - so i racked to secondary and dry hopped with an ounce of cascade today. The SG reading is at 1.003. Needless to say the beer is very watered down. Is there a way of adding something to fix this batch? Maybe some DME or something???

Click to expand...

Wow, that's really dry. You might want to revisit your thermometer because you probably mashed lower than you intended.

Grumpybumpy said:

Wow, that's really dry. You might want to revisit your thermometer because you probably mashed lower than you intended.

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From what I gather from everyone's post - the crush (or lack there of) on my grain wasn't enough. Wouldn't that be the cause for such a low OG and therefore a low FG?

I calibrated my thermometer with boiling point at my altitude.

The low FG could very well be due to the lack of sugar in the beer. The yeast didn't get tired and drop out before they were done eating.

Prymal said:

The low FG could very well be due to the lack of sugar in the beer. The yeast didn't get tired and drop out before they were done eating.

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True... I bet they're still hungry. Poor little guys!

I just brewed my second batch of BIAB last night (a Bavarian Hefeweizen) and did better - I think.

I made sure the grains were crushed more, however, this time I only boiled off 1/2 gal. during my 60 min. boil (last brew was 1 gal. boil-off). So I ended up with too much water in the end. So again a low OG.

Target Vol: 5 gal
Vol. into fermenter: 5.75 gal.

Target OG: 1.050
Actual OG: 1.041

The differences between the two batches were:
1. I used a new homemade immersion chiller which stopped my boil when i put it in.
2. It is warm and humid here right now (vs. last time it was cold and dry)

Questions:
1. Do you guys just boil longer if the volume is not right after 60 min., and how will that affect my 5 min. hop addition?
2. When your immersion chiller stops the boil do you add boil time to account for the time that your wort is not actually boiling?

If you had boiled off the extra half gallon you would have ended up a lot closer to your 1.051 target. I would guess 1.048 but I am not sure. I always check my pre-boil volume and volume at 30 minutes if it looks like my boil will be shorter or longer based on total evaporation so far I will adjust my finishing hop additions accordingly. This part of brewing just takes practice. I ended up with an extra gallon and a half once because of not checking my pre-boil volume and having a low evap rate due to humidity. If you don't have a sight glass on your kettle I would invest in one pronto. www.Brewhardware.com has a great kit put together by BoobyM who is an active member of this forum.

yeah I actually thought I would boil off another 3/4 gal. which would definitely have made a difference in OG. But I did my vol. calcs based on last brew in which it was very dry, whereas this time it's humid and warm. I will take the average and use that next time [3/4 gal. boil-off per hour]

Good to know about the mid-boil volume check and adjustment. I will do that too. I have marks on my spoon but didn't even bother to check. I was too busy attaching tubing to my immersion chiller. Which by the way is a game changer... I got down to 68 deg. in 18 minutes with a little stirring!