HERMS mill gap

[sheikyerbouti]

Finally bit the bullet on an electric brewery and I've read that with HERMS systems, a larger mill gap may actually result in higher efficiency.

I've tightened mine up from around .039 to .047 and didn't notice much of a difference in efficiency. I'm just wondering what other folks on HERMS systems are using for a mill gap.

 

[jmark]

Mine is an MM3 and I have the gap set at 0.045 for mine. To be honest I'm not terribly happy with the crush. If I open the gap much wider and I seem to get a LOT of uncrushed kernels. My efficiency is actually reasonable though - around 77% these days (had LOTS of issues early on) and that stays fairly consistent across most of my brews.

Edit... just for clarity - I have a 10 gallon HERMS system

 

[sheikyerbouti]

Thanks jmark.

First 3 brews, my efficiency blew dog...around 60 or so. Once I started sparging for an hour, it improved to 72%. My old cooler system gave me mid to high 70's, go figure. This is on a 20 gal HERMS system.

 

[jcav]

I have one also and use .045 and have great efficiency. I also mash out before sparging though. Here is a tip I picked up (from a well known brewer on a podcast) use a pound of rice hulls per 5 gallons. Many think it's just for people not wanting a stuck mash especially when using a lot of wheat in the recipe. It's not just for that, it also works amazingly at regulating the temperature in the entire grain bed so it's more even throughout!

John

 

[jmark]

Hey John... not to hijack, but next time you brew do you mind taking a picture of your .045 crush... I'd like to compare. Thanks.

 

[jcav]

Sure, no problem. I brew once a month (10 gallons) and I just brewed last week, so it will be next month.

John

 

[SilverZero]

Condition your grain with 2% of the grain weight in water sprayed finely over the grain and mixed together, and you can set the mill tighter, around .036 or so. Recirculate for a few minutes to set the grain bed before you start running it through the coil if you can. That's what I do and I get great efficiency, 80%+ normally, though it dropped a bit when I started fly sparging so I'm going back to the old drain and batch sparge method.

 

[sheikyerbouti]

Condition your grain with 2% of the grain weight in water sprayed finely over the grain and mixed together, and you can set the mill tighter, around .036 or so. Recirculate for a few minutes to set the grain bed before you start running it through the coil if you can. That's what I do and I get great efficiency, 80%+ normally, though it dropped a bit when I started fly sparging so I'm going back to the old drain and batch sparge method.

Thanks SilverZero!

 

[SilverZero]

Actually, you can set the mill even tighter (some people get below 0.030) if you're conditioning, but it really comes down to your mill and how the crush looks for you. Also, plan to save 1/2 a pound of dry grain to run through after milling to dry the rollers. They can get gummed up from the extra moisture.

I also saw the advice about leaving the mill wider for HERMS but I think it's just a matter of getting a good crush without shredding the husks. Rice hulls help (I've never used them) but a good grain bed means keeping the hulls intact. For me, conditioning helps me do this without leaving so many kernels totally intact.

 

[sheikyerbouti]

Hey, it's only 6:30am in Bend...why are you up so early?

 

[SilverZero]

Haha, snow day. I'm a teacher, the email buzzed my phone and woke me up early.

 

[kal]

I'm doing 0.045" on my setup (Monster Mill MM2, with Blichmann G1 and false bottom for the MLT). No flow issues at all and high efficiency. I've brewed beers with up to 60% huskless grain (such as weizen at 60% wheat and 40% pils) without using any rice hulls.

My crush:

Kal

 

[stevehaun]

I am at 0.045 as well with a monster mill. Good flow.

 

[jodell]

I'm doing 0.045" on my setup (Monster Mill MM2, with Blichmann G1 and false bottom for the MLT). No flow issues at all and high efficiency. I've brewed beers with up to 60% huskless grain (such as weizen at 60% wheat and 40% pils) without using any rice hulls.

My crush:

Kal

Sorry to hijack but is the blichmann dip tube with false bottom 1/2"? I have struggled the last couple brews with flow issues and realized most of my issues are my cheap false bottom

 

[kal]

Sorry to hijack but is the blichmann dip tube with false bottom 1/2"? I have struggled the last couple brews with flow issues and realized most of my issues are my cheap false bottom

According to Blichmann's website, the dip tube is indeed 1/2" OD. The dip tube is really short. It's not going to have a large effect on flow, especially on my setup (which I'm assuming you're asking about?) given that I have almost 75 feet of tubing/pipe after it including a 50 foot HERMS coil. That few inches of dip tube won't have an effect on flow.

Though that said, I may not be fully understanding the question.

Kal

 

[jodell]

According to Blichmann's website, the dip tube is indeed 1/2" OD. The dip tube is really short. It's not going to have a large effect on flow, especially on my setup (which I'm assuming you're asking about?) given that I have almost 75 feet of tubing/pipe after it including a 50 foot HERMS coil. That few inches of dip tube won't have an effect on flow.

Though that said, I may not be fully understanding the question.

Kal

I have made a clone of your system, however due to a budget, I am currently is 2 keggles for HLT and mash tun. I have used it multiple times with great results, but the last few times (probably 2) I have had a really slow recirculation. I know it's not a clog in the herms coil because I hooked it up to a garden hose to test it with no problems. The pumps are fine, so I'm not exactly sure what is going on other than the false bottom not doing well or my grains getting to finely crushed

 

[kal]

Most likely the false bottom and/or too fine of a crush. Not to derail this thread too much but if you like, start a thread over at my forum at TheElectricBrewery.com and post some pictures/more info and we can help. Cheers!

Kal

 

[jcav]

Hey John... not to hijack, but next time you brew do you mind taking a picture of your .045 crush... I'd like to compare. Thanks.

Here you go. I had my friend hold some up in the second photo to show it better.

 

[jmark]

Cool... thanks... that looks very similar to mine.

 

[augiedoggy]

My gap is down at .030 (I crush fairly slowly with my speed controlled motorized CK mill) and I recirculate with a rims which makes no difference in this regard but I use a cheaper bayou classic false bottom with a finer stainless braid under it as a last chance filter for the small DC pumps I use... I average 86%... I did recently try the rice hulls just to see what I might be missing but I still got the 1.8 gallon per minute on my flow meter with the 3gpm max 24v Dc pumps I use.

 

[303Dan]

I use the factory gap setting on my cereal crusher and get about 85% efficiency on my 10 gallon eHERMS system. That's with about a 45-60 minute fly sparge at 175 degrees. I do a 10 minute mashout at 170. The crush definitely made a big difference in my system, though, I was getting 70-75% when I was crushing at the LHBS.

Dan

 

[jcav]

Cool... thanks... that looks very similar to mine.

Your welcome, I'm just sorry it took so long. I brewed on Feb 10th and these pics had been sitting in my camera for over a week. I finally got off my butt and posted them for you. My guess is your probably getting in the 90's in mash efficiency. Brew house efficiency is a different story however, since your going to have losses in your hoses, chiller, boil kettle, etc. and your not going to get all of it into your fermenter. So I wouldn't worry to much about brew house efficiency as much. I get high 90's mash efficiency with my rig, but about 82 to 85 percent brew house efficiency (depending on the recipe) due to my losses. I am very happy with that. Most people are happy with 70 to 75 percent. Just my two cents. Enjoy your rig and make great beer!

John