Efficiency Question

Made my second all grain beer today, and have a few questions.

I used a corona mill to crush my grain, however I conditioned the malt first.

I'm BIAB'ing, and my first batch tasted great when I racked to secondary, but it's OG was low as well.

My efficiency into boiler was 88%, which I am relatively happy with, however, beersmith says my brewhouse efficiency was only 60%, based off the estimated OG of 1.065, and actual OG of 1.052.

I used 2.5 quarts of water to mash (1.76 lbs of grain), and another 3 quarts to sparge. I also added PH 5.2 stabilizer to my mash water to insure proper PH. However, I did not check it

Mash temp was 158 initially, fell to about 151. Sparge temp was 170. I mashed for an hour, then moved the grain bag to the sparge water (170 after addition of grain), where I sparged for 15 minutes. Then, I combined the mash and sparge water in my brew pot, and boiled for an hour.

My overall wort volume was pretty much right on (.75 gallon)/

To correct this, would I only need to boil longer to evap more water, causing my OG to increase? However, then my wort volume would be low.

I plan on buying some tincture of iodine before the next batch to be sure conversion is complete, perhaps there were still starches left to convert when I sparged.

I guess I can't complain a whole lot, as long as I'm happy with the taste, but being a rather technical guy, I'd prefer to be able to acheive the predicted outcome.

I don't quite understand. You had a boil volume of .75 gallon, for a .5 gallon batch? Is that correct?

What was the preboil OG and volume?

i was shooting for between .5 and .75 gallons of wort, boil size was about 1.38 gallons (5.5 qts)

preboil og, was 1.034

o4_srt said:

i was shooting for between .5 and .75 gallons of wort, boil size was about 1.38 gallons (5.5 qts)

preboil og, was 1.034

Click to expand...

So, at 1.38 gallons it was 1.034 and that is an efficiency of 73%. But the post-boil efficiency is 61%.

I don't do small batches, but I usually boil off 1 gallon per hour in a 6.25 gallon start. You boiled off about .75 gallon in an hour. Maybe a longer/harder boil would help if you simply wanted to increase the OG.

You could also increase your water amount in your mash if you wanted to start with a bit more wort. You can easily go up to 2 quarts per pound in a mash. You can sparge with up to 2 quarts per pound, also, so you were fine with the 3 quarts of sparge water.

I assume you had the grains "loose" in the bag, and stirred very well. If you didn't, that's something to correct for next time. I think iodine testing is a very good idea.

I stirred the mash every 15 minutes or so, I'll try stirring more next time.

Beersmith info:

Brewhouse Efficiency Based on Target Volume
Actual OG: 1.052
Actual Efficiency: 60.11%
Estimated OG: 1.065
Estimated Efficiency: 75%

Efficiency into Boiler:
Volume into Boiler: 27 cups
OG into boiler: 1.034
Planned boil volume: 27 cups
Estimated OG into boiler: 1.029
Efficiency into boiler: 88.43%

Efficiency into fermenter:
Actual Batch Volume: 12 cups
Planned volume: 12 cups
Efficiency as calculated from actual volume: 60.11%


8.5% (0.15 lbs) of the grain bill was flaked oats, not sure if that matters

My oatmeal stout recipe is 9% flaked oats, and it converted. I wonder, though, in such a small batch if you had enough diastatic power to fully convert. What else did you have in there? Was the grain really "loose", so that is was basically free-flowing, just contained by the bag?

I used around 1 lb maris otter, .34 lb 2 row, .15 lb crystal 60, .08 lb victory and .04 chocolate malt.

The bag was stretched out around the pot, so yes, it was fairly loose