56% mash efficiency - is it my crush?

[OptimusJay]

I have low mash efficiency and am trying to narrow down the most likely reason and I think it may be the grain crush.

I batch sparge.

Equipment:
10 gal orange HD cooler with a 36" SS braided hose.

Most recent grain bill:
3 lbs Marris Otter
3 lbs 2 row
1.5 lbs Munich
.5 lb C60
.5 Honey Malt

I fill the cooler with 140F water to get it warmed up, and let it sit for 30 minutes or so.
Empty that water then add about half of the strike water, pour in the grains, add the remaining strike water, and stir for probably 3 minutes.
Mash temp was 152. 45 minutes into the hour long mash i opened the cooler and stir again for probably 2 minutes then put the lid back on and let it sit for another 15 minutes. I follow use the Beersmith suggested 1.25 quarts/lb grain.

From here, I stir once more, maybe for another minute, let sit for a minute or so, then collect the cloudy first couple of quarts of wort and gently pour back into the mash cooler. I collect the first runnings. Next I add the sparge water (175F), stir again, let sit for a minute or so, collect the cloudy runnings, pour that back into the mash cooler and collect the second runnings until empty.

For the above grain bill I was targeting collecting 3.5 gallons of wort, and that is what I collected. However, the target SG based on 70 (or maybe 72%) mash efficiency was 1064 and I got 1050. I used a refractometer initially with the warm wort, then also cooled a sample to 65F and used my hydrometer. It read 1050.

After much reading on this section of the forum I am thinking that the crush size might be the reason for the low efficiency. Does my mash/sparge procedure look legit? I get my grain milled at the home brew store, maybe its time to look into purchasing my own mill? All opinions and feedback are appreciated.

Thanks,
Jay

 

[inhousebrew]

Sounds like you got it right. Do they let you adjust the size at the brew store? Try running it through twice to see if that improves things.

 

[progmac]

your process sounds exactly like mine and my efficiency is 75% at least.

i'd look to the crush and to your mash Ph.

 

[plankbr]

...For the above grain bill I was targeting collecting 3.5 gallons of wort, and that is what I collected. However, the target SG based on 70 (or maybe 72%) mash efficiency was 1064 and I got 1050. I used a refractometer initially with the warm wort, then also cooled a sample to 65F and used my hydrometer. It read 1050...

This is where I'm confused. It sounds like pre-boil gravity is what you measured, which is always lower than the post boil gravity. Would you be able to clarify a bit more? Did you measure after your boil? Have you tried splitting your sparge into 2 steps? (taking what you need for total sparge and splitting it in half).

 

[OptimusJay]

This is where I'm confused. It sounds like pre-boil gravity is what you measured, which is always lower than the post boil gravity. Would you be able to clarify a bit more? Did you measure after your boil? Have you tried splitting your sparge into 2 steps? (taking what you need for total sparge and splitting it in half).

Yes, the 3.5 gallons was wort collected from the mash/sparge process, pre-boil. Beersmith tells me the target pre-boil volume and pre-boil SG. These are the numbers I am referring to. This was a partial mash/partial boil recipe with very late addition of DME and also top off water to get a 5 gallon batch. But that's getting off the point of targeting why my mash efficiency is low. I have not tried splitting my sparge into 2 steps. Has that improved your mash efficiency? I'd certainly be open to that. What's the intended benefit of 2 spurges? Maybe the 2nd sparge rinses the grains an additional time and gets a bit more sugar from them?

Progmac,
I treated my tap water with a bit less than 3ml of lactic acid for 5 gal because I have pretty high alkalinity (per Wards Lab report). I used brunwater for that. That said, I don't have a pH meter to test during the mash to see where I'm at but its on my list of equipment to buy.

Inhousebrew,
Thats a good question. I don't know if they let us adjust the mill, but I'll find out next time.

Thanks for the input for far.
Jay

 

[plankbr]

One more thing to also consider is trying to mash @ 1.5 qt/lb. See if that makes any improvement on the efficiency.

 

[RM-MN]

Try a 90 minute mash. If your efficiency goes up significantly, blame the crush. The longer mash lets bigger grain particles get wetted deeper and leaches the sugar back out better.

 

[OptimusJay]

Do you brewers have any recommendations for trying either the 90 minute mash and/or the water/grain ratio on a small scale? I'd like to try these out but not on a full batch scale. But then again, I guess I would want to keep the equipment the same so as not to introduce other variables. Thoughts?

 

[orford]

The majority of conversion happens in the first 15 minutes of a mash and changing the ratio of water to grain will not have a huge impact on your efficiency either (both time and ratio will have a larger impact on the fermentability of the sugars in your wort however).

I would be inclined to guess that your problem is not in the conversion process but rather in your crush. When I first moved to DC the LHBS I was using has a terrible crush, my first batch came in at 56%, this was with a brewing system that had held around 85% efficiency for about 5 years using a different store's mill. I went back the next time and passed it through twice and my efficiency jumped to 60%... I finally bought my own mill and now am back at 85% pretty much everytime.

Buy a mill, save yourself the time, money and hassle.

 

[stpug]

It sounds very plausible that the crush of the grain is the issue. Fortunately, that's also fairly easy to identify simply by inspecting the grain either prior to or after the mash. You should not see any whole grains remaining. If your efficiency problem is truly crush-related then you should see plenty of uncrushed grain with the gravity discrepancy you posted.

Alternatively, you could post a detailed picture of your dry crushed grain on this forum and you'll get some helpful feedback.

 

[OptimusJay]

It may be too late, but here are a couple pics of the POST-MASH grains. Not sure if they will help in evaluating crush or not.

I will probably go the route of getting a mill for myself. That will be fun to research on which mode(s) would be best for me.

Jay

 

[orford]

I would rank my malt mill as the best purchase of all of my equipment. I love being able to mill my own grain!

 

[OptimusJay]

I would rank my malt mill as the best purchase of all of my equipment. I love being able to mill my own grain!

Which mill do you have?

 

[And1129]

I just got a mill and have just used it once so far, but the first batch i did with crushing my own grains gave me an increase of 10% from what my efficiency had previously been. I hope to keep tweeking my crush and other variables to push up my efficiency.

 

[ksut1547]

I can't help with which grain mill to buy. If you do a thorough search into the topic, roughly 95% LOVE the grain mill they bought. I based my choice on hands on experience with grain mills others bought. Price is also important, only you can decide how much you will pay for a grain mill. I won't say which one I went with, but I thought one of the higher priced ones felt durable and was right for me. Hope this helps.


Sent from my iPad using Home Brew

 

[Chadwick]

I also had some terrible efficiency issues. I bought my own grain mill and now I have great efficiency. A good crush is vital. I used to buy buy my grains pre-crushed and always got terrible efficiency. The crush of those grains was always questionable too. I eventually got tired of the problem and bought my own grain mill. Problem solved immediately. If you think about it, the cost of the grain mill will pay for itself in improved efficiency in the long term. Plus, now you can save money on buying whole grains, and they store so much better too.

For what its worth, that is my experience.

 

[Remmy]

I did a 90-minute mash with 17.5 lbs. of grain (crushed at LHBS) and ended up with 60% efficiency (post-boil gravity was 18 pts. lower than I had aimed for). Batch sparged.

 

[SteveHeff]

I was averaging 62-66% for the first 2 years of brewing. I, too, batch sparged. A friend of mine suggested that I had "hot mash water" in order to increase my first sparge temperature to 160-165. I would add between .5-1 gallon of near boiling water to my mash in order to mash out for 10 minutes. I saw an increase in 8-12% when I started doing this about 6 months ago. So 4 brews later, it still works and I don't think I'll ever brew without that step. It's worth trying...water is relatively free.

 

[cluckk]

If you are getting it crushed at the LHBS then the crush is going to be too large. They target a crush size that is less likely to cause a stuck sparge. It is also in their interest for you to get a lower yield so you buy more grain to brew with. You can try having them double crush it. That may get you a point or two. But your best option is to get your own mill and grind them yourself. By doing this I jumped from 72% or so efficiency up to 85%+. I occasionally hit 94%/

Another thing to check is the pH of your mash. But this will help you only so much. The best thing will be your crush size.

 

[PHDrunk]

It's probably your crush or pH, but if you really want to be sure (I.e. rule out lautering problems) I would try to separate your constituent lautering and conversion efficiencies.

Check out Kai Troester's page on diagnosing efficiency issues (http://braukaiser.com/wiki/index.php?title=Troubleshooting_Brewhouse_Efficiency). If you follow the cold readdition method, you can estimate lautering efficiency which will help diagnose the problem. Also, by measuring the SG of the first runnings you can get a handle on conversion efficiency.

As for crushing at your LHBS, I was noticing ~90% conversion with my brews crushing with their mill. I've started double crushing my grains to try and mitigate this. I only have one data point so far, but the conversion has increased a few percent so far.


Sent from my iPhone using Home Brew

 

[BansheeRider]

If you're doing partial mash beer you should look into the BIAB method. With a small grain bill you can easily do BIAB and have high efficiency. Just a thought....I never did PM, I jumped right into AG from extract brewing.

 

[OptimusJay]

Thanks for all the tips, suggestions, and info to research.

BansheeRider, this partial mash/partial boil was a rare occurrence. I typically brew all grain full boil.

Jay

 

[wilserbrewer]

fairly easy to identify simply by inspecting the grain either prior to or after the mash. You should not see any whole grains remaining. .

Hard to tell from a pic, looks like uncrushed whole pieces of grain are in the mash.

Are there whole pieces?

If yes, you have likely found your issue.




Sent from my iPhone using Home Brew

 

[OptimusJay]

Hard to tell from a pic, looks like uncrushed whole pieces of grain are in the mash.

Are there whole pieces?

If yes, you have likely found your issue.




Sent from my iPhone using Home Brew

Correct, there were what appeared to be completely in tact whole grains. Pretty sure it's a crush problem.

Thanks,
Jay

 

[BigGoat]

I've done 3 AG batches from AHS and have been at about 50% Time to order a mill since that seems to be the consensus of the many threads I've read about this. Thanks for all off the great info!

Sent from my VS920 4G using Home Brew mobile app

 

[Irish1225]

I've also started noticing low efficiency - 62-66%. I actually was not keeping very good notes until recently and I was very surprised to see my numbers so low. I have mostly been brewing for years with pre-crushed grain from NB and always noticed my beer wasn't as strong as I was hoping so I started using BeerSmith. I also made a beer a couple weeks ago that came in at 62% that I purchased at the LHBS. I noticed some grains were intact so I'm in the market for a new mill.

I hope it's the solution for me, as well...

 

[Scottie61]

Sounds like the same problem I had. Seems like I'm always ending up in such a hurry at the brew shop, with wife or kids waiting in the car, and grind, pay, and rush out, so didn't check my grains. My last two brews were low (low 50's), too, and I had noticed many uncrushed hulls the last brew, so started to get suspicious.

This last weekend's brew was the first use of my grinder (Cereal Killer, FWIW), and had *no* problems with efficiency. If anything my grind might have been a bit too fine, as my batch sparge seemed to run way slower than usual, but maybe that's really normal? I was also doing an Oatmeal Stout with flaked oatmeal and flaked barley which could have slowed things, too. Beersmith says I'm in the low to mid 70s using a batch sparge, and I'm happy with that.

BTW - I use a hygrometer, too, and have never been able to get near the estimated 'pre-boil' gravity that Beersmith has, so never measure it anymore. I always supposed it was because of the sample being too hot.

Scottie

 

[PHDrunk]

BTW - I use a hygrometer, too, and have never been able to get near the estimated 'pre-boil' gravity that Beersmith has, so never measure it anymore. I always supposed it was because of the sample being too hot.

Scottie

Yes, it is the temperature. Specific gravity is a measure of density which is temperature dependent. For wort below 100F you can ball park the actual gravity with a calculator (here's one at Brewers Friend: www.brewersfriend.com/hydrometer-temp). As the wort gets hotter however, this calculation is less reliable.

Personally, I grab samples of the first runnings and pre-boil wort and put them into the freezer as the wort is heating to a boil. Once they're down to 65-70F or so, I measure the SG and figure out my efficiency. This way, prior to the end of the boil, I know if I'm way off my target gravity. This means I can supplement with DME at this point if necessary. Also, since the wort is still boiling, I can add the samples right back into the kettle so I don't lose any wort to the various diagnoses.


Sent from my iPhone using Home Brew

 

[plankbr]

Here's a writeup I did a while back. I hope this helps. Stirring and doing 2 sparges helps drastically. I also have my own grain mill now, but prior to that, I was consistently getting ~76% efficiency from the LHBS.

https://www.homebrewtalk.com/f36/getting-better-efficiency-batch-sparging-447705/

 

[kanzimonson]

I think it might just be that you're making too small of a batch. I make small batches sometimes to make wort that I pressure cook for future starters. I use my regular equipment which typically makes 6gal+ batches. When I make these small ones, my efficiency is way low. Even though all the equipment and procedure is proportionate in size, the grains are still the size of grains.

 

[Scottie61]

This way, prior to the end of the boil, I know if I'm way off my target gravity. This means I can supplement with DME at this point if necessary. Also, since the wort is still boiling, I can add the samples right back into the kettle so I don't lose any wort to the various diagnoses.

Good idea adding the DME. When mine was low I just continued on, and ended up with a Scottish Ale at "session brew" strength. It still tasted pretty good, and folks seemed to like it.

Scott

 

[orford]

I have a BarleyCrusher and love it. I run it with a cordless drill and can grind 15# of grain in a matter of minutes!


Sent from my iPad using Home Brew