Mash thickness, stuck mash and rice hulls on grainfather, ace, klarstein

[beervoid]

Hello everyone,

I've recently started brewing bigger batches on a grainfather like system but i'm running into problems with a stuck mash.
My current water to grain ratio is on the low end if i'm correct (about 2.5liters per KG).
Total grain bill is about 12kg and I have only 30 liters in my mash.

I can't really change this as I've hit the max of my 50L system. I'm suspecting that the mash thickness is the culprit here as I have no problems with smaller batches and my grain mill should be fine. I'm working with only 9% flaked wheat and 9% flaked oats.

Consequently when running my pump to circulate the wort my mash get's stuck and as a result my mash temps are not steady.
Would adding rice hulls help?

Thanks

 

[Dland]

Rice hulls will help. The non-barely grains do tend to stick up a mash somewhat, at 18%, the effect is noticeable. I usually add rice hulls to batches with over 10% adjuncts.

 

[RM-MN]

Your 9% wheat and 9% oats are a big problem. That's nearly 1/5 of the mash with grains that have no hulls or have had the hulls removed. Hulls are important to form a filter bed. Adding rice hulls will help.

 

[thehaze]

Rice hulls / oat husks ( is what I can get and work just as well ) will definitely help, so you should maybe stock on it and have it at hand for every brew.

 

[couchsending]

it took a grain bill of 60% wheat to get a stuck mash with the Grainfather. Never had one with any wheat or oat percentages less than that. Lately I think I actually need to add some Flaked adjuncts to my grain bill to slow sparge down to get better efficiency.

Something else is happening. Milling your own grains?

 

[beervoid]

it took a grain bill of 60% wheat to get a stuck mash with the Grainfather. Never had one with any wheat or oat percentages less than that. Lately I think I actually need to add some Flaked adjuncts to my grain bill to slow sparge down to get better efficiency.

Something else is happening. Milling your own grains?

Thats what im wondering as well some people say they never get problems untill very high % of flaked adjuncts. Im milling my own grains yes. Even set the gap wider as I had the same problem on previous brew and was hoping it would fix the stuck mash.

The only difference I can tell atm is that I went from making a 5gal batch to making a 10gal batch and due to this my water to grain ratio is smaller so my mash thickness is higher.

What kind of mash efficiency do you get?
And what og?
My og is between 1.065 to max 1.070
Mash Efficiency 62%

 

[couchsending]

With the Grainfather I get generally over 80% mash efficiency. Bad batches tend to be in the low 70s. For me it’s directly related to sparge speed. My bad batches I think I’m getting some sort of channeling.

I step mash every beer
I generally stir twice, always once

Conditioning my grain results in a sparge that’s way too fast.

I was trying to keep a small amount water over the grainbed when I started sparging to avoid oxidizing the mash but it just led to sparges that were way to fast. Last few brews I’ve waited until much more water has left the grain bed and actually tred to compact it by pushing the top plate down so the sparge slows down. Seemed to work from an efficiency standpoint, we’ll see how the beers taste....

150+ batches in

 

[beervoid]

With the Grainfather I get generally over 80% mash efficiency. Bad batches tend to be in the low 70s. For me it’s directly related to sparge speed. My bad batches I think I’m getting some sort of channeling.

I step mash every beer
I generally stir twice, always once

Conditioning my grain results in a sparge that’s way too fast.

I was trying to keep a small amount water over the grainbed when I started sparging to avoid oxidizing the mash but it just led to sparges that were way to fast. Last few brews I’ve waited until much more water has left the grain bed and actually tred to compact it by pushing the top plate down so the sparge slows down. Seemed to work from an efficiency standpoint, we’ll see how the beers taste....

150+ batches in

What is your water to grain ratio?
And how big beers do you do?

 

[kbaggen]

Hi there, as other have said! Rice hills is very important if using oat/wheat, flaked!

But a wider milling sieze might also help a bit in general......!

Also try avoid the low mashing temperatur in the beginning........or at least I obsovered the stuck mash seems to get worser if the temperatur is in the lower end! So might be you should got for some beer styles at the high end to deal our system in!

I get 72% efficacy on my homemade system with a ratio of 2, and 75% at the ratio of 3 L/kg!

Klaus
www.posebryg.dk

 

[RM-MN]

Thats what im wondering as well some people say they never get problems untill very high % of flaked adjuncts. Im milling my own grains yes. Even set the gap wider as I had the same problem on previous brew and was hoping it would fix the stuck mash.

The only difference I can tell atm is that I went from making a 5gal batch to making a 10gal batch and due to this my water to grain ratio is smaller so my mash thickness is higher.

What kind of mash efficiency do you get?
And what og?
My og is between 1.065 to max 1.070
Mash Efficiency 62%

Bigger grain particles should help a bit but the downside is your mash efficiency goes down with the bigger particles. Set your mill back where it was and add the hulls to get the filtering you need. Your mash efficiency should be at least into the 80% range. Rice hulls or oat hulls are cheap and both work. It doesn't take a large weight of hulls, many people mention just a handfull which doesn't weigh much.

 

[beervoid]

Bigger grain particles should help a bit but the downside is your mash efficiency goes down with the bigger particles. Set your mill back where it was and add the hulls to get the filtering you need. Your mash efficiency should be at least into the 80% range. Rice hulls or oat hulls are cheap and both work. It doesn't take a large weight of hulls, many people mention just a handfull which doesn't weigh much.

I will be testing the rice hull theory soon. Just got a huge bag of it.
Any tips on amounts are welcome!
Will report back with my findings.

 

[couchsending]

What is your water to grain ratio?
And how big beers do you do?

It depends on the beer and the mashing regime. Beers are generally 1.044-1.064. Bigger beers than that the efficiency definitely starts to go down. The Grainfather dimensions are the cause, would be better if it was shorter and wider. For an average 5.5-6% beer it’s standard liquor to grist.