AG Efficiency

Hi, long time reader first time poster here. Like most lurkers I chose to make myself heard when I need help. I have made ~6 extract brews most of which came out very well. I recently bought a stainless AG kit and the transition has not exactly been smooth. I'm finding it very difficult to break the 65% efficiency barrier and was hoping someone might have some ideas. I have read a few threads on this subject but most of them seem to deal with batch sparging. I guess for the next brew I might try that although it seems like a shame to let this nice sparge arm go to waste....

My setup for the last brew was:

12 lbs belgian pilsner
0.5 lbs crystal 60
total grains 12.5 lbs crushed at 32 mil

Strike with 15.5 qt (+/- 1 qt) @ 170 with initial grain temp 65 and mash tun weight 8 lbs to mash @ 153. Mash tun is 10 gallon polarware with false bottom. Tun was preheated w/122 degree water and then the prewarming water was drained out the bottom valve so that only the deadspace below the false bottom contained 122 degree water when grain was added.

Hit the mash temp of 153 exactly and mashed for 60 minutes, temperature dropped to 149, applied low heat with stirring to bring the temp back up to ~ 151-152 and mashed another 30 minutes. Total mash 90 minutes. Iodine did not turn purple when added to a sample of the mash. Thermometer is a Blichmann - temperature double checked with a second electronic probe meat thermometer.

Approximately 3 quarts first runnings were drained out the bottom of the tun and poured back on top of the grain bed.

Sparge water was @172. Approximately 4-5 gallons sparge water was used, enough to get my desired preboil volume of 6.75 gallons. Sparge water was run through the arm to create 1/2" of water above the grain bed and the runoff rate was adjusted to maintain the water level above the bed throughout. Sparge was discontinued when the boil kettle contained ~5.5 gallons, and the tun was drained to reach 6.75 gallons in the kettle.

After a 60 minute boil I ended up with exactly 5.5 gallons as expected. SG was 1.052 indicating ~64% efficiency. Not bad, but I'd like to try and boost it 5-15% to save on grain and make bigger beers in the future.

Based on other threads the next actions I could contemplate taking to boost efficiency include:

- Switching to batch sparge and seeing how that does (could still use arm?).
- Asking the homebrew shop to switch to a smaller grain crush (26 mil?).
- More carefully measuring out sparge water (I just use enough to get above 5 gallons in the kettle, then drain the tun and that seems to yield about 6.75 gallons total).
- Any other suggestions greatly appreciated!

The other question I have concerns trub. I expected AG brewing will produce more trub than extract but I am getting a LOT of trub in the fermenter - will this affect the flavor of the beer? Should I consider straining / filtering the mash somehow as it drains into the kettle?

I am using whirlfloc and whirlpool siphoning (with a stainless steel scrubber as filter) from the kettle into the carboy as depicted in Homebrewer's Companion pp. 146. Still getting trub in the fermenter. Is it better to leave the last inch or so of beer in the kettle rather than tilting the kettle to get it all in the siphon?

Thank you to anyone who has read to the bottom of this 8 thousand word newbie treatise. Double thank you to anyone who responds. Triple thank you to homebrewtalk for getting me this far.

Well my suggestions are as follows:

1. Crush - When I went from my HBS crush to my own crush, I gained 10% better eff. That would be the first place I start.

2. Measurements - I noticed you used the terms "approx, just enough, and about".....even 1/2 gallon difference you will notice big eff. changes. Be a bit more precise with your measurements and your eff. might not be a bad as you think.

3. Mash volume - I have noticed better results mashing at about 1.5 to 1.75 qts/lb grain. Try upping that next time to see if that helps.

Those are about the only 3 things I seen that caught my eye. Seems like you have a great grasp on your situation and I think in no time you will figure out your system. Let us know how the next one turns out.

I was hovering around 65-70% with grain crushed at the store, once I got a barley crusher, I'm at 80% or a couple points higher.

You both mentioned crushing your own grain instead of getting it cracked at the store. My local store are pretty friendly so it might be possible to convince them to give me a custom crush.

What is the ideal size (mm or mill) to get the efficiency jump? I am not so worried about a stuck mash as I have a false bottom, so it might be possible to go pretty tight.

I also might consider buying the grain gobbler at morebeer.

Having just read the sticky at the top of this forum, I think part of my problem is that 12.5 lbs grain should require 6.25 gallons of sparge water, which would overflow my kettle. So maybe I need to accept that larger grain bills are going to be less efficient due to lower volume of sparge.

Did you take a pre-boil gravity reading? That would help narrow your problem between the mash or water volume for the boil....

Papazian says the ideal crush should be 1/3 husk, 1/3 seed (or whatever is inside the husk - can't remember the name) and 1/3 flour. My LHBS's crusher has an adjustment knob. Chances are you can adjust the crush to however you want it if you just ask.

Also, if you are fly sparging, you're not putting all the water in at once. You are putting like an inch of water in and then matching the water-in flow with the water-out flow. So, it shouldn't overflow your mash tun (or are you saying that you don't have enough room in your kettle for all the liquid coming out?)

Another thing is fly sparging slower maybe? If your sparging is too fast maybe you can turn down your runoff flow rate.

A little trub in the fermenter won't matter at all.

pmeice86 said:

Papazian says the ideal crush should be 1/3 husk, 1/3 seed (or whatever is inside the husk - can't remember the name) and 1/3 flour. My LHBS's crusher has an adjustment knob. Chances are you can adjust the crush to however you want it if you just ask.

Also, if you are fly sparging, you're not putting all the water in at once. You are putting like an inch of water in and then matching the water-in flow with the water-out flow. So, it shouldn't overflow your mash tun (or are you saying that you don't have enough room in your kettle for all the liquid coming out?)

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Thanks for the reply. Yes, I am trying to match the inflow and outflow as you describe. The comment about overflow was in relation to the boil kettle. If I used the recommended quantity of sparge water (1/2 gallon per lb grain) I would need 6.25 gallons of sparge water for my 12.5 lbs, in which case the liquid flowing out of the tun would overflow the kettle - so I have to use less sparge water than the ideal.

I also think part of the problem was the speed of my fly sparge - I cranked open the sparge water tank to full and the outflow from the tun to like 2/3 - and finished my sparge in 25 minutes. A lot of people here are saying that will not give good efficiency and a slower sparge of 45-60 minutes is necessary. As BierMuncher said, the water should be soaking down through the grain bed, not flowing.

Next brew I will try the following to increase efficiency of my mash:

- Tighter grain crush if possible.
- Sparge water temp 185.
- Slow runoff speed for a total sparge time of 45-60 min.
- Will still probably have to use less sparge water than ideal.
- Anything else?

Do you check your mash pH? That's supposed to improve efficiency, but I'm no expert. Also, do you do the iodine test to make sure it's all converted? Is that 6.25 gallons of sparge water for a 5 gallon batch?

pmeice86 said:

Do you check your mash pH? That's supposed to improve efficiency, but I'm no expert. Also, do you do the iodine test to make sure it's all converted? Is that 6.25 gallons of sparge water for a 5 gallon batch?

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Iodine test was negative. The 6.25 gallons was a theoretical ideal for that grain bill (12.5 lbs grain) but I will have to use less because my brew kettle is not large enough to collect that volume of sparge water + the mash water.

Mash pH is something I hadn't considered. Do most people just dump in the recommended amount of 5.2 buffer or do you need to buy a pH meter and monitor it carefully?

Alaska, my process is almost identical to yours. I get 75-80% eff. I think your hunch about sparge volume may be the culprit. Your mashing with approx 1.25/ qt per pound (like I do), with that thickness you will indeed ideally need 6+ gallons of sparge for a 12.5 pound grain bill. You are probably leaving behind some sugars. I know you don't have kettle space for that much volume.....but have you tried brewing a batch with a smaller grain bill (10lb or less)? Try a smaller grain bill with ideal sparge volumes....if your efficiency is still off, then look at the crush. If you continue to make big beers, you may want to invest in a bigger kettle, or just toss in some dme to hit the numbers. Hope that helps.

Takes a while to get dialed in on your system. When I first did all-grain I was hitting around 65% too. After a few batches I was getting 75% pretty consistently/ Now I seem to be getting close to 80%.

AlaskaWortChiller said:

Mash pH is something I hadn't considered. Do most people just dump in the recommended amount of 5.2 buffer or do you need to buy a pH meter and monitor it carefully?

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I too am having some efficiency problems...but I did buy some PH test strips from my LHBS. They aren't as good as a PH meter, but they do the trick and are far cheaper than the meter.

You should buy some pH test strips so that you know if the 5.2 buffer has done it's job. They're like 5 bucks for a jar of 100 strips, so it's not something that is going to set you back much.

I just noticed that you changed the original message. The average sparge volume for a 5-gallon batch in Papazian's books are 2.5 gallons. I'm not sure where the math comes from, but 6.25 seems to be a little bit much.

Also, regarding a lot of trub in the boil, I'm guessing that's a speed or water flow thing. My first batch had TONS of grain parts in it, but I was draining pretty quickly... The next batch I drained pretty slowly, with the ball valves of the HLT and mash tun maybe 1/4 open. I also made sure there was 1" of clear water on top of the grain bed the whole time. When you take the first runnings, that is your time to adjust flow and figure out how to keep the grains in the tun. Start super slow and speed up just a little if you need, going until the liquid runs clear of grain material. Someone once told me 1 gallon every ten minutes was a good rate of flow.

pmeice86 said:

Also, regarding a lot of trub in the boil, I'm guessing that's a speed or water flow thing. My first batch had TONS of grain parts in it, but I was draining pretty quickly... The next batch I drained pretty slowly, with the ball valves of the HLT and mash tun maybe 1/4 open. I also made sure there was 1" of clear water on top of the grain bed the whole time. When you take the first runnings, that is your time to adjust flow and figure out how to keep the grains in the tun. Start super slow and speed up just a little if you need, going until the liquid runs clear of grain material. Someone once told me 1 gallon every ten minutes was a good rate of flow.

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The hot break portion of the trub will be there regardless. If you are getting husks and grain bits in your boil kettle I don't think you are Vorlauf'ing appropriately or you are flowing at too high a rate. On that note, a good steady and slow sparge, when fly sparging, has helped me hit ~84% most batches. Sparging for my 10+ gal batches is roughly 90 min.

- Condition your malt and crush it yourself.
- What was the gravity of your final runnings? My guess is you left a lot of fermentables in the tun based on your description. Sparge more slowly and you will be able to collect more fermentables in less volume.
- Check your pre-boil gravity and adjust so you hit your gravity targets. Your efficiency might be off, but don't let it affect your gravity by either boiling off or topping up before starting your primary boil session.

WVbrewer said:

Alaska, my process is almost identical to yours. I get 75-80% eff. I think your hunch about sparge volume may be the culprit. Your mashing with approx 1.25/ qt per pound (like I do), with that thickness you will indeed ideally need 6+ gallons of sparge for a 12.5 pound grain bill. You are probably leaving behind some sugars. I know you don't have kettle space for that much volume.....but have you tried brewing a batch with a smaller grain bill (10lb or less)? Try a smaller grain bill with ideal sparge volumes....if your efficiency is still off, then look at the crush. If you continue to make big beers, you may want to invest in a bigger kettle, or just toss in some dme to hit the numbers. Hope that helps.

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Thanks for all the great suggestions. At first I thought grain crush was my problem but now I am realizing that the more likely culprits are sparge volume and sparge flow rate. I definitely finished my sparge in 20-25 minutes by opening the valves full blast. Next time I will aim for a 60 minute sparge and a lil trickle coming out of the tun. The large amount of grain material that ended up in my kettle is further proof that I need to reduce the flow rate, and maybe get a smaller diameter hose for the tun outflow...

As WVbrewer suggested, I will also try a smaller grain bill of 10 lbs with an ideal sparge of 5 gallons, so that my sparge water will fit in the brew kettle..the risk here is that if I hit 64% efficiency again on 10 lbs I will end up with a really small beer.

Lots of people have suggested altering the grain crush and I will try that if possible...

I have a question on the slow runoff sparge time, since I am still pretty new to AG brewing. that 45-60 min run off time, does that include both the initial runnings and the sparge, or is that 45-60 min each? I've been draining the tun in about 15 to 20 min, then sparging and draining at another 15-20, so I think I'm right on(maybe a little fast but close), but just want to double check. But if it's 45-60 per draining, then I am way off.

dummkauf said:

I have a question on the slow runoff sparge time, since I am still pretty new to AG brewing. that 45-60 min run off time, does that include both the initial runnings and the sparge, or is that 45-60 min each? I've been draining the tun in about 15 to 20 min, then sparging and draining at another 15-20, so I think I'm right on(maybe a little fast but close), but just want to double check. But if it's 45-60 per draining, then I am way off.

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I think the folks above are talking about fly sparging.

I do batch sparging like you do and just let it flow out as fast as I can without any issues.

AlaskaWortChiller said:

As WVbrewer suggested, I will also try a smaller grain bill of 10 lbs with an ideal sparge of 5 gallons, so that my sparge water will fit in the brew kettle..the risk here is that if I hit 64% efficiency again on 10 lbs I will end up with a really small beer...

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You can always cut your sparge into two equal parts and sparge twice. I do this with big beers that do not easily fit In my cooler. This can also hel you maintain temperatures.