Missed my numbers

[dallasd9]

Just looking for some input to the results of my last brew. Here are the specifics

BIAB
Target 5 Gallions, Actual 4.5
Style: IPA
Grain: 15#
Mash: 1 hour, no sparge, recirculation with recirculation rinse. PH 5.4
Boil: 1 hour, with three Hop additions
Target OG 1.074, Actual 1.060
Target FG 1.017, Actual 1.012

Question #1: What would have caused me to miss my number by this much?

Question #2: Will this change the flavor since the gravity numbers are so off?

Taste is Ok, currently carbonating

Thanks

 

[wepeeler]

1. What was your starting volume ie mash water volume, final volume ie total in kettle after the boil, and volume into fermenter? If you wanted 5 into the fermenter, but got 4.5, your OG should actually have been higher than predicted. How did you mill your grain?

2. Yes. OG, if you measured correctly, is pretty significantly different from target to actual. That leads to balance issues with malt profile and bitterness. Chances are you'll still have decent beer.

Most likely, it was volume and crush that caused you to miss your numbers.

 

[Hoochin'Fool]

Weird, usually when the volume is less than expected, the wort is sweeter than expected. Fifteen pounds of grain in a 5 gallon batch ought to generally get you in the range of 1070 to 1080 (Brewer's Friend suggests 70% eff would get you 1078). Did you weigh the grain yourself? Did the grain have a good crush? Maybe you didn't give the bag time to fully drain? (Personally, I squeeze it like it owes me money)

 

[dallasd9]

1. What was your starting volume ie mash water volume, final volume ie total in kettle after the boil, and volume into fermenter? If you wanted 5 into the fermenter, but got 4.5, your OG should actually have been higher than predicted. How did you mill your grain?

2. Yes. OG, if you measured correctly, is pretty significantly different from target to actual. That leads to balance issues with malt profile and bitterness. Chances are you'll still have decent beer.

Most likely, it was volume and crush that caused you to miss your numbers.

Answer to your question:
1) Mash water volume was 5 gallons. It was 4 gallons after draining and squeezing bag. I added 2 gallons prior to boil for 6 gallons in kettle. Ended up with a little over 4.5 gallons in kettle after boil. Grain was milled that day with the same 2 roller mill I have used many times before (husk all cracked with fair amount of dust)
I took my final OG reading with my refractometer (calibrated with distilled water) figuring I was going to have to add more water to bring my volume up for the fermenter but was shocked to see how low it was. Like you said, it should have been higher.

Thanks for your feedback

 

[dallasd9]

Weird, usually when the volume is less than expected, the wort is sweeter than expected. Fifteen pounds of grain in a 5 gallon batch ought to generally get you in the range of 1070 to 1080 (Brewer's Friend suggests 70% eff would get you 1078). Did you weigh the grain yourself? Did the grain have a good crush? Maybe you didn't give the bag time to fully drain? (Personally, I squeeze it like it owes me money)

Answer to your questions:
I did not weight the grains myself.
(I will in the future)

The grain was milled that day with the same 2 roller mill I have used many times before (husk all cracked with fair amount of dust)

I let the bag drain for a while and then squeezed it until I could get no more liquid out of it.

Thanks for your feedback

 

[Hoochin'Fool]

In that case, the only things I can think of:

• OG measurement fail (sample too warm for hydrometer)?
• LHBS short-changed you on grain.
• Your mash temp was a lot cooler than you thought.

Worst case, the beer turns out fantastic, and you'll never, ever be able to recreate it!

 

[hout17]

Answer to your question:
1) Mash water volume was 5 gallons. It was 4 gallons after draining and squeezing bag. I added 2 gallons prior to boil for 6 gallons in kettle. Ended up with a little over 4.5 gallons in kettle after boil.

Are the 2 gallons that you added just water to get your boil volume up or did you sparge with it to get more sweet wort into the kettle?

I'm asking because if you just added water to the kettle to get your boil volume up then this would explain your low gravity readings.

Also efficiency is generally lower with higher OG beers as your water to grain ratio goes down.

 

[balrog]

higher gravity mashes are notoriously less efficient.

 

[SFC Rudy]

Mash water volume was too low. With grain absorption you should have mashed with 7.9 gallons to get 6 gallons into the BK. I’m amazed that you got 4 gallons out of it with only 5 gallons of strike water.

Is this your recipe? Was it designed for no sparge? Off the shelf recipes require 20-25% more grain to reach the same gravity.

 

[MikeCo]

Make sure you have accounted for grain absorption correctly. It's easier to do a full volume, no-sparge mash if your kettle is large enough; then there's no need to account for top-off water. For a 5.5 gallon batch, I usually start with around 7.75 gallons of water depending on the amount of grain. Squeezing will significantly affect the results as well.

Also, be sure to crush the grains finely enough. My 2-roller gap is set at 0.030 inch.

 

[wepeeler]

Answer to your question:
1) Mash water volume was 5 gallons. It was 4 gallons after draining and squeezing bag. I added 2 gallons prior to boil for 6 gallons in kettle. Ended up with a little over 4.5 gallons in kettle after boil. Grain was milled that day with the same 2 roller mill I have used many times before (husk all cracked with fair amount of dust)
I took my final OG reading with my refractometer (calibrated with distilled water) figuring I was going to have to add more water to bring my volume up for the fermenter but was shocked to see how low it was. Like you said, it should have been higher.

Thanks for your feedback

No problem.

For a 5 gallon batch, I mash in 9 gallons of water. Grain absorbs about 1/2 gal, and I boil off about another 1.5 gal, leaving me with 7ish at the end of boil. I then dump 6-6.5 gal into my fermenter.

Something went wrong in your mash. Seems like bad efficiency and no sparge. I've never lost a full gal from grain absorption. Maybe you didn't squeeze enough. And if you added water right into kettle, and not through bag, you probably missed a decent amount of sugar.

 

[IslandLizard]

What they said! ^

No-sparge is designed to use the full volume of water in the mash, while your kettle must be large enough to hold all the grain and the water, and have some spare room to stir all that well.
Better mash/brewhouse efficiency can be achieved by doing a sparge. A dunk sparge, using a container large enough would be my preference, but pour-overs with squeezes work for some too.

Have you encountered this issue before?
Much small grain kernels in there such as wheat, rye, oats?
Did you check your mill gap, on both sides? They can creep.
Recirculating the mash can be an issue (channeling), as can heating the wort while recirculating, possibly denaturing enzymes if the wort gets too hot.

 

[dallasd9]

In that case, the only things I can think of:

• OG measurement fail (sample too warm for hydrometer)?
• LHBS short-changed you on grain.
• Your mash temp was a lot cooler than you thought.

Worst case, the beer turns out fantastic, and you'll never, ever be able to recreate it!

I always cool the wort to 68 before taking a hydrometer read in. I think we can dismiss that. Might have been short changed on the grain. I will always measure in the future.

I did let (not on purpose) the mash temp drop down to 140 before heating back up to 154 and stirring.

Lol, I love your "wort case" I'll go with that

Thanks for your feedback.

 

[dallasd9]

Are the 2 gallons that you added just water to get your boil volume up or did you sparge with it to get more sweet wort into the kettle?

I'm asking because if you just added water to the kettle to get your boil volume up then this would explain your low gravity readings.

Also efficiency is generally lower with higher OG beers as your water to grain ratio goes down.

I think you onto something. I just added the water to the kettle. Next time I will heat any additional water up to 170 and sparge with it.

I've never had this problem before but this is a higher OG beer than I've ever brewed.

Thanks for your feedback

 

[dallasd9]

Mash water volume was too low. With grain absorption you should have mashed with 7.9 gallons to get 6 gallons into the BK. I’m amazed that you got 4 gallons out of it with only 5 gallons of strike water.

Is this your recipe? Was it designed for no sparge? Off the shelf recipes require 20-25% more grain to reach the same gravity.

I've never brewed a beer before with this much grain. It was too much for my kettle (8 gal). Lesson learned.

The recipe is from the brew store I purchased it from and it was not designed for BIAB so it required a sparge. Another lesson learned.

Thanks for your feedback

 

[balrog]

People have reported similar results "dunk sparging" in cool water, if that's any help (not having to heat up more water).

 

[tracer bullet]

I dunk sparge in cool water. Not sure how much better it is if heated, probably a little, but it's far easier for me. Less work and also less burning my hands squeezing the bag!

At some point, find a good method, and stick with it. Afterwards you'll have a good idea of your efficiency and can just go forward with it.

 

[BrewZer]

Did you grind your own grain? My first inclination is you didn't get it fine enough.

 

[mac_1103]

People have reported similar results "dunk sparging" in cool water, if that's any help (not having to heat up more water).

If you don't heat it before you sparge you just have to heat it after you sparge. The advantage of a hot sparge is that your brew kettle boils faster. The advantage of a cool sparge, as noted above, is that you won't burn yourself squeezing the bag.

 

[dallasd9]

Did you grind your own grain? My first inclination is you didn't get it fine enough.

Yes, I have milled my last five brews with no issues. It's a pretty good grind with all husk being cracked and a fare amount of powder.

Thanks for your feedback

 

[dallasd9]

If you don't heat it before you sparge you just have to heat it after you sparge. The advantage of a hot sparge is that your brew kettle boils faster. The advantage of a cool sparge, as noted above, is that you won't burn yourself squeezing the bag.

I like your suggestion. I use silicone gloves for squeezing the bag but it's still pretty hot.

 

[balrog]

Full disclosure: I'm a BIAB-er utilizing gravity alone, non squeeze, non sparge, 1.030-1.055, 10gal pot, typically 7gal full vol water to 8-9# grain. Effort vs reward - you gotta figure what works for you, and then do it EVERY TIME for repeatability.

 

[SFC Rudy]

I've never brewed a beer before with this much grain. It was too much for my kettle (8 gal). Lesson learned.

The recipe is from the brew store I purchased it from and it was not designed for BIAB so it required a sparge. Another lesson learned.

Thanks for your feedback

Look into reiterated mashing for your higher gravity beers. It sounds intimidating, but isn’t. Only added about an hour to my brew day.

 

[dallasd9]

Look into reiterated mashing for your higher gravity beers. It sounds intimidating, but isn’t. Only added about an hour to my brew day.

I will do that. Thank you for the info

 

[tracer bullet]

I'll also suggest this is a time to buy a small bag of DME (dried malt extract) and have it on hand "just in case". Golden light for example. If your gravity #'s are low, you can add some DME (let it dissolve, mix in, and so forth) and then recheck your numbers and move on when you're happy. You may wish to re-evaluate a process so it doesn't happen again, but it'll bump the beer you are making at that particular time.

 

[IslandLizard]

Target 5 Gallions, Actual 4.5
Grain: 15#
Mash: 1 hour, no sparge, recirculation with recirculation rinse. PH 5.4
Boil: 1 hour
Target OG 1.074, Actual 1.060

Something is definitely off, yes!
I think it's happening in the mash. You're not getting full extraction for some reason. Maybe it's recirculation/wort heating related, as I already mentioned in Post #12.

When I put that same 15# grain amount in a 5.5 gallon batch, I get a target gravity of 1.080, per Beersmith. That's with a Brewhouse Efficiency of 80%.
When I drop that BH efficiency to 75%, due to it being a higher gravity brew, the OG drops to 1.075, which is pretty much what I will end up with in my fermenter.

Also, adding 2 gallons of water (instead of sparging) and then boiling 2.5 gallons back off is completely counterproductive, but we can address that later.

 

[rburrelli]

You had a pretty thick mash there if only 5 gallons of strike water. That might account for something.

 

[Bobby_M]

Just looking for some input to the results of my last brew. Here are the specifics

BIAB
Target 5 Gallions, Actual 4.5
Style: IPA
Grain: 15#
Mash: 1 hour, no sparge, recirculation with recirculation rinse. PH 5.4
Boil: 1 hour, with three Hop additions
Target OG 1.074, Actual 1.060
Target FG 1.017, Actual 1.012

Question #1: What would have caused me to miss my number by this much?

The typical problem is when the brewer says "my numbers", they actually mean "someone else's numbers". If you got the recipe from somewhere, that recipe assumes a certain mash and brewhouse efficiency, which correlates a batch size to grain weight to OG. YOUR system and process yields a different (LOWER) efficiency so the recipe numbers are in fact not your numbers. Now, even if you used the right amount of water to begin with (you didn't), your actual 1.060 OG was not far off from what I'd expect. You need to go into your favorite brewing software and enter a lower brewhouse efficiency (something like 65%).

Question #2: Will this change the flavor since the gravity numbers are so off?

Yes, it's different than the intended recipe but not likely bad. It's still an IPA.

1) Mash water volume was 5 gallons. It was 4 gallons after draining and squeezing bag. I added 2 gallons prior to boil for 6 gallons in kettle. Ended up with a little over 4.5 gallons in kettle after boil.

I see it was mentioned already, but just to corroborate, you really can't do a concentrated mash and then top off with plain water without majorly tanking efficiency. To be extra clear, YOU CAN do that but you have to scale the recipe to make up for the obnoxiously low efficiency. If you're doing this because your kettle can't handle a drop more liquid, then you would benefit greatly from a larger kettle. 10G is bare minimum, but I like 15 for a 5 gallon BIAB so there are no limits.

Assuming you'll wonder why concentrated mashes yield lower efficiency, it raises the mash gravity so the portion of liquid that stays in the grain contains more sugar than if the mash was more diluted.

My "5 gallon" batches into the packages are 5.75 into the fermenter, 6.5 at the end of the boil, 8 at the beginning of the boil so MOST batches start with 9 to 9.5 gallons of water.