First BIAB Problems

[JRazz]

Hi all im new to this so hope you can help,

I made a porter yesterday evening and undershot my Original Gravity of 1.061 and got 1.045, I heated 37.5L of water to 73c added grain dropped temp to 67c and held for 60 min and mixed every 20 min. my efficiency apparently was 55% approx. which isn't the best attached below is my brew smith info.

Recipe Specifications
--------------------------
Boil Size: 37.36 L
Post Boil Volume: 30.54 L
Batch Size (fermenter): 23.00 L
Bottling Volume: 22.00 L
Estimated OG: 1.066 SG
Estimated Color: 74.6 EBC
Estimated IBU: 21.2 IBUs
Brewhouse Efficiency: 75.00 %
Est Mash Efficiency: 95.6 %
Boil Time: 60 Minutes

Ingredients:
------------
Amt Name Type # %/IBU Volume
5.43 kg Gladfield Ale Malt (6.0 EBC) Grain 1 81.9 % 3.54 L
0.40 kg Gladfield Medium Crystal Malt (111.0 EBC) Grain 2 6.0 % 0.26 L
0.30 kg Gladfield Light Chocolate Malt (900.0 EBC) Grain 3 4.5 % 0.20 L
0.30 kg Gladfield Roasted Wheat (550.0 EBC) Grain 4 4.5 % 0.20 L
0.20 kg Gladfield Dark Chocolate Malt (1300.0 EBC) Grain 5 3.0 % 0.13 L
15.00 g Southern Cross [13.00 %] - Boil 60.0 min Hop 6 16.5 IBUs -
15.00 g Fuggle, New Zealand [6.10 %] - Boil 15.0 min Hop 7 3.8 IBUs -
12.00 g Golding, New Zealand [4.20 %] - Boil 5.0 min Hop 8 0.9 IBUs -
1.0 pkg Nottingham Yeast (Lallemand #-) [23.66 ml] Yeast 9 - -


Mash Schedule: BIAB, Full Body
Total Grain Weight: 6.63 kg
----------------------------
Name Description Step Temperat Step Time
Saccharification Add 41.41 L of water at 73.0 C 68.9 C 60 min
Mash Out Heat to 75.6 C over 7 min 75.6 C 10 min

Sparge: If steeping, remove grains, and prepare to boil wort
Notes:
------

 

[AZCoolerBrewer]

I plugged your recipe into my calculator and got 1.050? It seems to me that rather than missing by .015 you missed by .004. Missing by .004 could be explained in a correction for hydrometer temp or any number of issues that I wouldn’t worry too much about.

 

[JRazz]

I plugged your recipe into my calculator and got 1.050? It seems to me that rather than missing by .015 you missed by .004. Missing by .004 could be explained in a correction for hydrometer temp or any number of issues that I wouldn’t worry too much about.

Thanks! what calculator did you use?? https://www.brewersfriend.com/brewhouse-efficiency/???

 

[AZCoolerBrewer]

My bad. I thought that your base malt was 3.43kg. I’m not sure why I saw it like that. I also use brewers friend. My guess as to why you’re efficiency was so low is that you didn’t squeeze your bag at all. The last AG beer I made was full volume, no sparge, no squeeze. My efficiency was right in the same ball park as yours.

 

[JRazz]

My bad. I thought that your base malt was 3.43kg. I’m not sure why I saw it like that. I also use brewers friend. My guess as to why you’re efficiency was so low is that you didn’t squeeze your bag at all. The last AG beer I made was full volume, no sparge, no squeeze. My efficiency was right in the same ball park as yours.

I did do my best at the squeeze, starting to think i might have started with too much water or not had a consistent 67c due to being a big pot and brewing at night in 5deg outside

 

[kevin58]

BIAB often results in lower mash efficiency. You can improve that by crushing your grains finer. If that's not feasible you can always recalculate your recipe for the lower efficiency and add more fermentables to reach your gravity goal.

I do full volume BIAB and when I started my efficiency was around 60%. I re-set the rollers on my mill from .038 to .025 and started getting about 72 to 75%. Yesterday I double crushed for the first time and my efficiency was 80%. I also mashed for almost 90 minutes. I used to stir about every 20 minutes as you describe but I started stirring just once at the beginning to make sure there are no dough balls and then I cover it and leave it.

Keep an extra pound or two of DME on hand too. If your pre-boil gravity is too low you can bump it up with a little DME.

 

[tmendick]

Your volumes seem crazy, you lose almost 7l post boil to the fermenter?

Did you hit your predicted post boil?
Did you do any measurements during the brewday?

 

[SteveH aka shetc]

I highly recommend the BIAB calculator at www.biabrewer.info. It provides 80% efficiency without requiring special steps such as extra crushing.

 

[El Nino]

I had a similar problem myself, I got about a 58% efficiency on my first brew. Did you buy the grains crushed, or crushed at the LHBS?

First run, I did a single crush at the LHBS.

I finally got to 70-75% efficiency by:
- Double crush (Still at the LHBS)
- Mash for 90 minutes instead of 60.

If you're getting a pre-crush/LHBS crush, you're not getting a really fine crush most likely. The double crush improved my efficiency by 5-6%, but the 90 min mash made a big difference and got it to the level I needed it to be. For now I'll keep doing this process, but if I buy more equipment, my next purchase will be a grain crusher.

So if you have the money, probably the next best thing to do is get a grain crusher. If not, then you can still get an efficiency jump by double crushing and mashing longer. I'd say if you can get around 70% that's golden.

 

[JRazz]

BIAB often results in lower mash efficiency. You can improve that by crushing your grains finer. If that's not feasible you can always recalculate your recipe for the lower efficiency and add more fermentables to reach your gravity goal.

I do full volume BIAB and when I started my efficiency was around 60%. I re-set the rollers on my mill from .038 to .025 and started getting about 72 to 75%. Yesterday I double crushed for the first time and my efficiency was 80%. I also mashed for almost 90 minutes. I used to stir about every 20 minutes as you describe but I started stirring just once at the beginning to make sure there are no dough balls and then I cover it and leave it.

Keep an extra pound or two of DME on hand too. If your pre-boil gravity is too low you can bump it up with a little DME.

Thanks for this good to hear I wasn’t only one first off, when you say a little DME how much roughly would you Add

 

[JRazz]

I highly recommend the BIAB calculator at www.biabrewer.info. It provides 80% efficiency without requiring special steps such as extra crushing.

Couldn’t find the calculator?? Looks like just a forum ?

 

[JRazz]

I had a similar problem myself, I got about a 58% efficiency on my first brew. Did you buy the grains crushed, or crushed at the LHBS?

First run, I did a single crush at the LHBS.

I finally got to 70-75% efficiency by:
- Double crush (Still at the LHBS)
- Mash for 90 minutes instead of 60.

If you're getting a pre-crush/LHBS crush, you're not getting a really fine crush most likely. The double crush improved my efficiency by 5-6%, but the 90 min mash made a big difference and got it to the level I needed it to be. For now I'll keep doing this process, but if I buy more equipment, my next purchase will be a grain crusher.

So if you have the money, probably the next best thing to do is get a grain crusher. If not, then you can still get an efficiency jump by double crushing and mashing longer. I'd say if you can get around 70% that's golden.

Yeah got them crushed and asked for double but can’t guarantee they did but I’ll mash longer next time and see, would love a crusher but bit pricey at the moment

 

[JRazz]

Your volumes seem crazy, you lose almost 7l post boil to the fermenter?

Did you hit your predicted post boil?
Did you do any measurements during the brewday?

I know sounds crazy right but I have a 70L pot and it’s 45cm, used beer smith and simple brew in a bag and both said the same

 

[DeeEnvy]

Couldn’t find the calculator?? Looks like just a forum ?

You have to dig for it.
Edit: Found it
https://biabrewer.info/viewtopic.php?f=5&t=1869

 

[SteveH aka shetc]

Yep, DeeEnvy found the BIABacus. It may seem a little daunting at 1st but it really is pretty clever. The forum members are very helpful.

 

[applescrap]

Great thoughts here, maybe squeeze your sack harder.

Man sorry i dont understand liters, wish I did. Was taught quarts and gallons, so i could be off here. Your water seems like a lot. And if you had boiled off the three gallons or so difference between boil and fermenter and still had low eff then that would be crush, etc...but if you had excess water that maybe you left in kettle with trub or whatever than the beer will be more diluted. The more diluted the less strong. You could have fixed it on brew day by boiling longer. That will have some affect though on hop bitterness, more isomerization, and will change color a little. How big of a deal this is depends on what you are making. Brew calculators etc can help you. Note that many love lower abv beers and there is nothing wromg with that. Sounds like you did a great job with your brew.

 

[cloudybrewer]

Your volumes seem crazy, you lose almost 7l post boil to the fermenter?

And, apparently, only 0.14L to grain absorbtion if I'm correct that you didn't sparge. For us standard measurement guys and gals, that's less than 5 fluid oz of absorbtion for a 14.7 lb grain bill.

 

[cloudybrewer]

Post Boil Volume: 30.54 L
Batch Size (fermenter): 23.00 L

If you had knocked your water volumes down and had zero losses from the kettle to the fermenter, you would have had an OG of 1.060 with the recipe calling for 1.061. It seems to me that you hit the OG almost exactly, but your system has such a large kettle loss that you need to use more grain than the recipe calls for to compensate. Could you explain to us why 7.54L didn't make it to the fermenter? How did you get that number and did it actually look like that much liquid left in the kettle?