Low efficiency?

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Piruz

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Hi! I know theres tens of these posts, but everyone has their own story and problem and how to solve it.

My problem was today, when brewing hefeweizen, I got only 55% efficiency! I use Brewersfriend software for calculations and it said my efficiency dropped from normal 70% to 55%.

First, my recipe:
1.25 kg wheat malt
1.25 kg pilsner malt
6.5L water on mash in, wanted to try ferulic acid rest so 43C first 10 mins.
Then added 5.5L boiling water to ramp it up fast to 66C. So 12L water now.
60 min rest. Temperature stayed on 65-66 whole time.
Mash Out at 76 for 15 mins.

No sparge, just pulled the bag up and let it drip over kettle. (Didnt drip much even when squeezed)
Got 10L of wort.
Got to rolling boil fast.
Hops in and 60 min boil.
Chilled with immersion chiller in 20 mins to 18C. After chill 8L wort left.
Added yeast and put it in fermentor.

I got estimated OG of 1.055 for 10L of wort in calculator, now got only 8L and hitted my OG.
Mash pH was 5.6 and my water was filtered with carbon filter (dont know if it affects anything but tried it.)

So.... Is this because of no sparge?
Or am I missing something else here?
I'm happy with 8L, but of course I want to always improve my brewing methods and get best value for money spent.

Cheers! :)
 
Last edited:
I'm skeptical of your mash pH. The acid rest should help, but consider 15 to 20 minutes at 44 ish. You still might need a touch of lactic or other acid. 66 is fine for a hef. Check the soupiness of the grain bed. Assure the grain is fully covered and not compacting. Stir it every 10 to 15 minutes during the mash. Definitely check the grind. If you aren't recirculating, finer is better. For the fun of it, compare your thermometer against another one. Bet your efficiency comes up next time.
 
Tested my pH twice, so not sure if my pH papers are incorrect or what.

My grains comes already grinded in LHBS for amount I need (I know these guys grind grains only when they get order in) and they were grinded 3 days ago.

I stirred mash only once, so maybe that's one thing I should improve.

And I have 2 thermometers, glass and digital. So they should be spot on.

But thanks for the advices! I'm going to brew dunkelweizen in couple days so gonna pay more attention to everything.
 
Your biggest issue is that your conversion efficiency was only about 77%. Acceptable conversion efficiency is 90% or better, and good conversion efficiency is 95% or better. Low conversion efficiency is almost always due to too coarse a crush. Crush can be a bigger issue with wheat, since the kernels are smaller than barley, so the same mill gap gives a worse crush. You might be able to increase your conversion efficiency somewhat by extending your mash time. But to get where you should be, you really need a finer crush.

No way you were going to get a post boil volume of 10 L given your strike volume, grain absorption, and boil off. Your grain absorption was about 0.8 L/Kg which is reasonable for an unsqueezed BIAB. Boil off was 2 L, which is also reasonable. So, 8 L post-boil is reasonable.

If you had hit 90% conversion efficiency, your OG would have been about 1.063 - 1.064, and at 95% conversion about 1.066 - 1.067.

Brew on :mug:
 
So my next investment would be own grain mill? This hobby isn't going to be cheap one... :D

Or I need to ask for LHBS guys to do finer crush for me. Thats judt odd, because I know these guys are somewhat pro-brewers and should know good average crush size for every grain. I don't know really how fine or coarse crush should be, but there's always some fine flours in my bags of grains and I do add them all to the mash.

And yeah, my 10L post boil was given with 14L of water and 70% eff. which isnt possible since I got only 15L kettle.

But since I mashed with smaller amount of water I thought I could dilute it after mash so I could get my attempted volume, but noticed my pre boil gravity was too low so did calculations and noticed the extremely low efficiency.
 
Oh just googled... It seems that since I'm no sparge BIAB brewer, my grains can be pulverized. :D Or atleast finer is better. Luckily I have old blender which hopefully can do the second crush for my grains.

Cheers!
 
Don't turn it into flour :)

Maybe just ask your shop if they can grind for biab, or run the grains through twice.
 
Would be nice to see how the milled grain looks like - those pics have solved the case in many threads. I think this is the main cause here as well. If the water is low in calcium you want to adjust pH by adding some calcium (it stabilizes Ca-dependent amylases as well). Although not familiar with BIAB, I think it's good to rinse the bag carefully after the mash.
 
So my next investment would be own grain mill? This hobby isn't going to be cheap one... :D

Or I need to ask for LHBS guys to do finer crush for me. Thats judt odd, because I know these guys are somewhat pro-brewers and should know good average crush size for every grain. I don't know really how fine or coarse crush should be, but there's always some fine flours in my bags of grains and I do add them all to the mash.

And yeah, my 10L post boil was given with 14L of water and 70% eff. which isnt possible since I got only 15L kettle.

But since I mashed with smaller amount of water I thought I could dilute it after mash so I could get my attempted volume, but noticed my pre boil gravity was too low so did calculations and noticed the extremely low efficiency.

It doesn't have to be an expensive mill for BIAB. One like this works great. http://www.discounttommy.com/p-189-...=pla&catargetid=320011640000015183&cadevice=c
 
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