Mashing a Low Gravity

[John Burns]

I've been brewing for a year now and I usually do partial mash brews which most of my beers came out great however, I decided to switch to all grain mash. My last 2 beers I've brewed both ended 20-30 pts below my target original gravity I feel like I followed all the procedures correctly but I continue to see the same results. I wanted to make a 3 gallon Single Mash beer using BIAB method. Here is my recipe
4 lbs 5 oz of Maris Otter
8 oz of Carapils
.5 oz of Simcoe @ 25 mins remaining
.5 oz of Simcoe @ 15 mins remaining
.5 oz of Simcoe @ 10 mins remaining
.5 oz of Simcoe @ 5 mins remaining
1 oz of Simcoe 10 days Dry hop

Had my grains crushed by my local brew shop, asked him to crush it very finely and I was doing a BIAB brew style. Strike water was 157F using mash water of 4.5 gallons of water. I did not mash out/sparge because I could easily squeeze the bag and drain the liquid of the of mesh bag using a pulley system. My mash temperature was at a constant of 152F for 60 minutes. After mashing my pre-boil water was 4 gallons. My boil off is 1 gal/hr. Boiled the wort and finished with exactly 3 gallons. My gravity should of been 1.060 however, I ended with 1.030.

Only possible issues I could think of is I did not monitor my pH levels (read from "How to brew" optimal pH is 5.2 to 5.5) or squeezing the bag and not sparging (read from "How to Brew" from john palmer than sparging isn't necessary since gravity will force out all the sugars from the grain).

The link below seems to be the similar issue I'm having
https://www.homebrewtalk.com/forum/threads/efficiency-issues-missing-og.660770/

Please any insights would be helpful.

 

[RPh_Guy]

Looks like you hit about 50% Brewhouse efficiency. That definitely needs improvement.

Sparging does help improve efficiency, but your process has some sort of problem that needs addressed.

Temperature: Have you calibrated your thermometer? What kind is it? Dial thermometers can be wildly inaccurate of improperly calibrated. Do you measure the temperature at various locations in the mash?

Crush: Did you visually inspect the crush? There should have been a fair amount of flour for a fine crush.

Time: An hour should be plenty of time for full conversion. Did you stir the grain to make sure there were no "dough balls"?

Mash pH: This is the big unknown with your recipe. Maybe your water is crazy alkaline and affecting conversion. You could try using reverse osmosis purified (RO) water or distilled water next time and see what happens. Any number of brewing calculators can help you hit an appropriate mash pH. Brewing salts are cheap. The basics you need are lactic acid, gypsum, and calcium chloride.

Hope this helps

 

[John Burns]

Looks like you hit about 50% Brewhouse efficiency. That definitely needs improvement.

Sparging does help improve efficiency, but your process has some sort of problem that needs addressed.

Temperature: Have you calibrated your thermometer? What kind is it? Dial thermometers can be wildly inaccurate of improperly calibrated. Do you measure the temperature at various locations in the mash?

Crush: Did you visually inspect the crush? There should have been a fair amount of flour for a fine crush.

Time: An hour should be plenty of time for full conversion. Did you stir the grain to make sure there were no "dough balls"?

Mash pH: This is the big unknown with your recipe. Maybe your water is crazy alkaline and affecting conversion. You could try using reverse osmosis purified (RO) water or distilled water next time and see what happens. Any number of brewing calculators can help you hit an appropriate mash pH. Brewing salts are cheap. The basics you need are lactic acid, gypsum, and calcium chloride.

Hope this helps

Yes my brewing efficiency has been 50% and really needs improved. To answer your questions. For thermometers I use the dial thermometer and no I kept it in the same location, crushing I watched him crush the grain myself this time, the first time I did not watch. I did stir the grain throughout the mash and their wasn't any residue or dough balls.
Do you think changing my dial thermometer for a electronic thermometer and measuring the pH next batch might improve accuracy? I read that water pH would have a effect on mashing efficiency, most enzymes work optimal at 5.2 to 5.5 but I didn't think it would have this amount of significance.

 

[RPh_Guy]

A dial thermometer is fairly simple to calibrate, if you have another thermometer you trust.
1. Heat some water to around 150°F according to the trusted thermometer.
2. Use the nut on the back of the dial thermometer to spin the face until it matches the trusted thermometer.

If you don't have a trusted thermometer you could use ice water and boiling water as calibration points.

Water chemistry is quite important for improving beer quality in general. I have seen major efficiency reductions from drastically out of range pH, so it certainly may be causing your issue.

This thread is a reasonable starting point if you can get some RO or distilled water:
https://www.homebrewtalk.com/forum/threads/a-brewing-water-chemistry-primer.198460/

Otherwise you need to get a report of the mineral content of your tap water in order to properly make adjustments.

 

[RM-MN]

About the only factor that can make that much difference between expected efficiency and what you got would be the crush of the grain. The other factors are important but the crush is the most. While you may have been watching the LHBS mill the grain, unless you know what to look for you might have missed the clue.

I'm a fan of the cheap Corona mill for BIAB. Since your bag that does the filtering can deal with the extra fine milling, get one and set it tight. I would expect your efficiency to be in the upper 70% with that. The Corona mill will set you back about $20 if ordered through Walmart, perhaps a bit more from other sources.

https://www.walmart.com/ip/COKO-Man...led-Nuts-Commercial-Home-Use-Silver/118653072

 

[Homergah]

If you decide to get a digital thermometer, be warned that they can be just as inaccurate as a dial. My calibrating thermometer is the old style with rising liquid.

 

[chickypad]

I agree the top 3 culprits are usually crush, crush, and crush. I'd typically not suspect pH but as mentioned above if you had really alkaline water it might be possible your pH could be so far off to affect conversion. That is a very pale grist and you mashed at about 4 qts per lb (very thin), both of which could push you toward a fairly high pH.

I also just wanted to mention that you need to adjust the expectations for the recipe. While your efficiency was pretty bad around 50% when I plug that into software, you never should have expected 1.060 which would have required 100% mash and lauter efficiency. For that recipe at a respectable 82% efficiency you would have gotten about 1.049.

 

[VirginiaHops1]

I do BIAB and my brewhouse efficiency is terrible, because I buy my grains pre-crushed. I was getting it from Morebeer and Midwest Supplies, and was getting 50-60% generally, which I could live with for the time being. Recently ordered some from Adventures in Homebrewing and as soon as I saw the grain I knew I would have issues. Batch came in under 50%. So yeah, I think I'm finally biting the bullet and getting a grain mill. OP, I would either get yourself one or make sure your LHBS is crushing it really fine, before even investigating other possible causes.

 

[LittleRiver]

... BIAB method...grains crushed by my local brew shop...

I agree with everyone else, if you get control of your grain crush your efficiency will improve significantly. I BIAB and my grain mill was one of the best brewing purchases I've ever made.

 

[RPh_Guy]

I think I'm finally biting the bullet and getting a grain mill.

It'll definitely pay for itself via bulk unmilled grain savings and increased efficiency.

 

[balrog]

I always bought from Ritebrew.com, they allow order by ounce, and will double crush, and I repeatedly got 72% eff. Consistency was more important than chasing a few, or even 10, percentage points. That being said, ordering uncrushed and using my Corona mill is great as I now consistently get good % (76-8, but less w wheat-centric grists) eff, I can order 2 batches at a time to save shipping costs, and the grain will be fresher the less time idly sitting around crushed.