Stop me if you know what I did wrong (efficiency)

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shoengine

shoengine

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I just brewed the Zach and Jack's Amber from the recipes database, and my OG was way off. According to my ingredients, at the suggested efficiency I should have obtained around 1.050 OG, but I was at 1.032. I'm going to be completely honest about the steps I took, even though they may seem to be stupid in parts (because they are).

My method was:
1. Heat water to 166-167F.
2. Dunk bag, stir, cover.
3. After about 10 minutes, checked the temperature and it was hovering around 156-157F. After another 20 minutes, stirred, and temp was around 155. About 10 minutes to go, checked again and it was around 151.
6. Pulled the bag out, sparged with room temperature water, ended up about 7.5 gal (target was 7).
7. Checked SG, showed 1.022. Realized that I was going to boil some off, but began to worry.
8. Squeezed bag (even more water now!)
9. Boiled for 70 minutes (added 5 minutes on each side of the hops addition to try to boil more off).
10. Checked gravity. 1.032. Welp, that didn't work.
11. Boiled a cup of water, added the 7oz of corn sugar I had laying around and added it. Shook a bunch and retook the reading. 1.032.
12. Put into fermenter.

I want to do another batch next Saturday, but I am afraid that my process is utterly broken. Is this simply too much water for the recipe? Do I need to avoid sparging and just throw in more malt?
 
All else in the process being equal, using more water always increases lauter efficiency, because you leave less of the sugar behind in the spent grain. More water also decreases the SG due to dilution.

We can't know if your efficiency was bad just from your low SG/OG. We also need to know the volume of wort when you measured that SG. If your post boil volume was too high by a significant margin, then your OG will be low by a similar margin.

Brew on :mug:
 
Thanks for the replies. Grain was milled at the LHBS. Crush looked good.

The recipe called for a mash vol of 12.75qts, boil volume of 7gal, for a 5.5gal batch. My mash volume was the 12.75qts. I over sparred then squeezed the bag and ended up with somewhere between 7.5 and 8 gal. My post boil volume was just above 6gal. Mash constituents were:

8.5lbs 2 row base malt
1lb Munich
1lb Caramel\crystal 80
.5lb Carapils\Dextrine
 
Did you have the grain loose in the bag, so that it had plenty of water touching each grain? Was it easy to stir? That seems like it would be a very thick mash, and would likely be the problem.

Why did you choose such a thick mash? I'd highly recommend going with at least 1.5 quarts of water per pound of grain or even more.
 
Your initial water at 167F is pretty high, so what was your mash temp goal?

You mentioned you dunked the bag when you got your water to temp. Assuming you had the grain bag filled when you dunked it like a tea bag?

If so, line your kettle with the bag, then slowly add grains while stirring to make a nice smooth mash. No grain balls...slow and easy add the grains. This helps kick start the conversion .
 
shoengine said:
I just brewed the Zach and Jack's Amber from the recipes database, and my OG was way off. According to my ingredients, at the suggested efficiency I should have obtained around 1.050 OG, but I was at 1.032. I'm going to be completely honest about the steps I took, even though they may seem to be stupid in parts (because they are).

My method was:
1. Heat water to 166-167F.
2. Dunk bag, stir, cover.
3. After about 10 minutes, checked the temperature and it was hovering around 156-157F. After another 20 minutes, stirred, and temp was around 155. About 10 minutes to go, checked again and it was around 151.
6. Pulled the bag out, sparged with room temperature water, ended up about 7.5 gal (target was 7).
7. Checked SG, showed 1.022. Realized that I was going to boil some off, but began to worry.
8. Squeezed bag (even more water now!)
9. Boiled for 70 minutes (added 5 minutes on each side of the hops addition to try to boil more off).
10. Checked gravity. 1.032. Welp, that didn't work.
11. Boiled a cup of water, added the 7oz of corn sugar I had laying around and added it. Shook a bunch and retook the reading. 1.032.
12. Put into fermenter.

I want to do another batch next Saturday, but I am afraid that my process is utterly broken. Is this simply too much water for the recipe? Do I need to avoid sparging and just throw in more malt?
Click to expand...
How did you determine the temp used for step 1?
What temp did you intend to mash at?
What was your grain bill in pounds?
What final volume came out of the boil kettle?
 
Beernutz:
1. Grain amount and temperature input into a calculator with a mash temp goal of 155F
2. 155F
3. 11lbs
4. Just over 6gal

Morrey:
Goal was 155
I filled the grain bag then dunked and stirred. Didn't think about putting the bag in first. That makes sense.

Yooper:
Thick and thin are fairly relative at this stage for me. It wasn't oatmeal, but it wasn't like I just tossed dry rice into water either. Maybe a cream-of-wheat sort of consistency? I didn't stir after about half an hour into the mash as I was concerned about radiation so I can't tell you how thick it ended up.

I just accepted the water volume default multiplier in the calculator of 1.25qts/lb. I think I did 1.5qts/lb back in May when I last did this. Think it could just be as simple as that I didn't have enough water and stuck my mash?
 
My crush, btw

homebrew-batch-00009-znj-grain.jpg
 
The crush could be finer- but that's not going to give you such low efficiency.

When you dough in, line the bag into the vessel and then clip it or something to hold it in place. Use at least 1.5 quarts per pound (more is fine, especially for BIAB), then stir it like it owes you money. Stir again. Stir again. Check the temperature in a couple of places to make sure it's equalized throughout. Then stir again, for good measure. The grains should be loose, and the water should be touching every grain. "Cream of wheat" is a good goal, as long as it's thin cream of wheat- think runny and soupy, not porridge like!

I have no idea what you mean about fear of radiation. You got me there!
 
Yooper said:
I have no idea what you mean about fear of radiation. You got me there!
Click to expand...

I think he means fear of losing heat from the mash tun via radiative cooling with the lid open.

Agree with the rest of the posters about changing the mash-in process, dry bag full of grain will lead to both dry spots within the grain and an uneven temperature spread from inside to outside unless you stir like an outboard motor.

Placing the empty bag in the mash tun and adding the grain while stirring, I use a 45cm whisk to make sure the grain is full mixed with the water, will eliminate that as a source of low efficiency.

Just to confirm, your gravity measurements were either at calibration temp for your hydrometer or corrected for temperature? Just making sure.
 
bruce_the_loon said:
Just to confirm, your gravity measurements were either at calibration temp for your hydrometer or corrected for temperature? Just making sure.
Click to expand...

That is what I was thinking as well. If my math doesn't suck, a measured gravity of 1.032 at 150° F yields a corrected gravity of 1.050. When I take gravity readings during the mash and boil, I always note the actual reading and the temperature with my thermopen, and then go back and note the corrected gravity.
 
There seems to be a number of possible causes for lower than expected OG proposed above including inadequate grain crush, mashing at too high a temp, and the idea your OG was actually higher than you measured due to temp offset during the reading.

Your situation is definitely odd. Was the 166-167 strike temp you used what the calculator called for? Which calculator did you use?
 
Ah, good call. My gravity readings, while not at 150F or even close, we're certainly above 68F (ambient was 85!) that gives me some hope. I can't believe I forgot about calibration. Ah well.

I will make copious notes about not being gentle to the grains, using at least 1.5qts\lb for mashing, and pouring the grains in after placing the bagin the water. Thanks for all your help!
 
beernutz said:
There seems to be a number of possible causes for lower than expected OG proposed above including inadequate grain crush, mashing at too high a temp, and the idea your OG was actually higher than you measured due to temp offset during the reading.

Your situation is definitely odd. Was the 166-167 strike temp you used what the calculator called for? Which calculator did you use?
Click to expand...

Odd is a polite way to put it. I guessed on the ambient storage temp of the grain and chose 155F as the mash temp, so as I lost temp I would stay above 150F. I can't remember if I used Brewer's Friend or Brewblogger...
 
Just remember, any temperature of the mash over 165 will lock the enzymatic activity and whatever grain was affected will act as if it was never even there....

So be very careful about the mash in... I'd be tempted to mash in lower, and add hot water to bring it up to temp..

This is the issue I'm having with my system, and I'm going to recirculate next time to keep the mash temp consistent throughout the mash process...
 
r8rphan said:
...

So be very careful about the mash in... I'd be tempted to mash in lower, and add hot water to bring it up to temp..

...
Click to expand...

Would it be better to raise the temp of the grain more than ambient so that relatively cooler water could be used?

Looking at the calculator, it appears that my strike temperature was driven mostly by the low volume of water, and somewhat by the higher mash temp (155F). So is it generally a good idea not to exceed 165F at any point in regards to mashing?
 
shoengine said:
Would it be better to raise the temp of the grain more than ambient so that relatively cooler water could be used?

Looking at the calculator, it appears that my strike temperature was driven mostly by the low volume of water, and somewhat by the higher mash temp (155F). So is it generally a good idea not to exceed 165F at any point in regards to mashing?
Click to expand...

No, you can use whatever water temperature you need to get your strike temperature. For me, I often use 168 degree water for my strike water to hit 152 degrees in my system. It's unusual to need that- but my grain room in the basement is in the 50s at times. When you add the water, you stir really well, so the temperature drops quickly. Normally, people who use room-temperature grain need about an 11 degree or differential between mash temp and strike temp.
 
shoengine said:
Thanks for the replies. Grain was milled at the LHBS. Crush looked good.

The recipe called for a mash vol of 12.75qts, boil volume of 7gal, for a 5.5gal batch. My mash volume was the 12.75qts. I over sparred then squeezed the bag and ended up with somewhere between 7.5 and 8 gal. My post boil volume was just above 6gal. Mash constituents were:

8.5lbs 2 row base malt
1lb Munich
1lb Caramel\crystal 80
.5lb Carapils\Dextrine
Click to expand...

Ok. 12.75 qts is only 1.16 qt/lb with 11 lb of grain. This is too thick a mash. When batch sparging you should forget about using a specific water to grain ratio. To maximize lauter efficiency you should target roughly equal volumes for first runnings and sparge runnings. An easy way to get close to this is to use 60% of your total brewing water for strike, and 40% for sparge. In your case that would have been about 5.25 gal (21 qts) for strike, resulting in a mash thickness of about 1.9 qt/lb, and 3.375 gal (13.5 qts) for sparge. Also, to maximize lauter efficiency, you should squeeze the bag before you sparge, and after you sparge. The before sparge squeeze is more important than the post sparge squeeze.

Your biggest issue however, is your low (less than 60%) conversion efficiency. This is likely a combination of your coarse crush, high mash thickness, high strike temp, and maybe dough balls and pH out of range. With proper mash parameters it is relatively easy to get better than 90% conversion efficiency.

Mash efficiency equals conversion efficiency times lauter efficiency, so to maximize mash efficiency, you need to maximize both conversion efficiency and lauter efficiency.

Brew on :mug:
 
1.1 qt/lb is a bit thick, but wouldn't cause a loss of 20+ points of efficiency. So that's not it.

The only time I've ever had such an incredible efficiency failure was when I let Northern Brewer mill my grains and they looked like the pic above. So it's likely crush, or bad measurement.
 
SpeedYellow said:
1.1 qt/lb is a bit thick, but wouldn't cause a loss of 20+ points of efficiency. So that's not it.
Click to expand...

But it definitely could be in this case- the grains were in a bag and probably not thoroughly wetted inside. Without the grains being stirred/wetted well, the conversion efficiency would suffer greatly, and that seems to be what happened here.
 
shoengine said:
Lautering in BIAB is just a fancy word for the process of the wort transiting the bag, correct?
Click to expand...

Lautering is separating the wort from the grain. In BIAB we move the grain and leave the wort in place. In a traditional MLT they move the wort and leave the grain in place. Sparging is rinsing, and is part of lautering, since it removes more sugar from the grain.

Brew on :mug:
 
Thanks for all the advice and analysis. I made a few changes based on what I learned in this thread and some other research on the Saison I did today. First, when grinding, I didn't fill the hopper, I slowly poured the grain into the wheels. I checked the grains and they were thoroughly cracked. Second, water volume. I increased the volume to roughly 1.9-2.0qts/lb. Third, I stirred while a friend poured into the submerged bag. Fourth, strike water temperature. I calculated the strike temperature using brew smith, and with the increased water volume and lower mash temp, my strike water was only 156-157F. Fifth, I stirred. A lot. Every fifteen minutes when checking the temperature. Additionally, this recipe called for a 75min mash.

When all was said and done, I was showing 89% efficiency after plugging in the numbers. This was much better.

beer-saison-2017.JPG
 
also calibrate your hydrometer. Put it in 68° water and look if it's at 1.000
It's also really weird that you had the same reading after adding corn sugar. Even when measuring at a higher temperature there should have been a difference.
 

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