Stuck mash

[Turfgrass]

I’m in the process of making a stout and I have a stuck mash. The particle size must be to small and it’s slow going through the MT’s false bottom and over to the pump. It is recirculation, but very, very slow and it’s causing my temps to be off. The slow go through the HERmS coil has the grain temp at 149 with a target of 156. Stirring the grain bed hasn’t done anything to help. Any suggestions, or just mash at 149??

 

[Cavpilot2000]

Nothing wrong with mashing at 149.

Next time, get a Brew N' Bag or other bag to line your MT. Use it in conjunction with your false bottom, the latter of which will prevent the bag from blocking the outlet.

 

[Rockn_M]

I've had that problem before and had to switch the pump output and inputs in the MT. This way the water blows out the debris causing the stuck mash.

 

[Turfgrass]

It improved slightly. Very little trickle, but enough that I was able get the temp to a range of 152-156 and most stable around 152-153.

Probably a lot of junk in the pump too. The bleeder ball valve didn’t produce any grain, but I didn’t try to crank it wide open.

I’ve been thinking of a brew bag since this started.

I’ve never brewed a stout before and it smells more like brewed coffee.

 

[millatime]

+1 on the brew bag. It has been great for me. I had many stuck sparges no matter the grain size and the BB is awesome. I bungie it around my mash tun so I can stir no problem when I batch sparge. No more stuck sparges since.

 

[Turfgrass]

I opened up the mash pump while the wort was boiling and it was clean. I think the grain bed was just to tight. I’m going to double check my mill grinder and use a brew bag next time.

I screwed up the mash ph too.

Long afternoon.

 

[RM-MN]

I’m going to double check my mill grinder and use a brew bag next time.

Since you are planning to use a brew bag, set your grinder tighter. Efficiency is driven by the milling of the grain as is the time for conversion. I've been cutting my mash down to 30 minutes because my conversion is over.

 

[Turfgrass]

Since you are planning to use a brew bag, set your grinder tighter. Efficiency is driven by the milling of the grain as is the time for conversion. I've been cutting my mash down to 30 minutes because my conversion is over.

How do you know when your conversion is over? Iodine Test?

What spacing do you suggest on the mill?

 

[RM-MN]

How do you know when your conversion is over? Iodine Test?

What spacing do you suggest on the mill?

The iodine test is pretty accurate but you need to use the iodine on the grain particles, not the wort. Without knowing the mill you have I can't tell you what spacing. I'd probably tighten it until it won't feed the grain through and then open it just a bit.

With my Corona mill set tight the conversion is over well before the 30 minutes even but I have learned that it takes more time to extract the flavor. I hate flavorless beer. That's why I don't recommend less than 30 minutes for a mash, regardless of how fine you mill.

If you have a refractometer it works pretty well for telling when conversion is over as the gravity quits changing but you do need to stir the mash well before taking a sample as the top of the wort will be lower gravity and it takes time for it all to equalize unless you stir.

 

[Turfgrass]

The iodine test is pretty accurate but you need to use the iodine on the grain particles, not the wort. Without knowing the mill you have I can't tell you what spacing. I'd probably tighten it until it won't feed the grain through and then open it just a bit.

With my Corona mill set tight the conversion is over well before the 30 minutes even but I have learned that it takes more time to extract the flavor. I hate flavorless beer. That's why I don't recommend less than 30 minutes for a mash, regardless of how fine you mill.

If you have a refractometer it works pretty well for telling when conversion is over as the gravity quits changing but you do need to stir the mash well before taking a sample as the top of the wort will be lower gravity and it takes time for it all to equalize unless you stir.

I have the Barley Crusher malt mill and it is set up at .39 spacing by the company.

 

[RM-MN]

I have the Barley Crusher malt mill and it is set up at .39 spacing by the company.

Try it much closer, using a "trial version" credit card or a .025" feeler gauge. You may find that you need to lift the brew bag a bit when draining the tun to get more filter area.

 

[Turfgrass]

Try it much closer, using a "trial version" credit card or a .025" feeler gauge. You may find that you need to lift the brew bag a bit when draining the tun to get more filter area.

The crush already seems real fine, so I’ll have to double check the gap.

 

[brewbama]

I use a cooler mashtun with a false bottom and a Brew Bag as a filter. I use a RIMS tube and recirculate thru the entire mash. I found three variables thru research, trial, and error that has resulted in consistent mash efficiency: 1) I use a fairly thin mash 1.75 qts/lb. 2) I use a fairly coarse crush to allow permeability of the grain bed. 3) I use a consistent setting on my pump output linear flow valve (5/16”). These three variables allow flow across the heating element without getting stuck causing pump cavitation while simultaneously giving me good mash efficiency (routinely 92 plus or minus 2).

This is what I learned on my system: Crushing too fine promotes channeling around the grain bed vs flowing thru it by pumping the fine flour unto the top of the grain bed. This layer has to be permeated to allow flow thru it otherwise the wort flows around the impenetrable layer. Pros use knives to cut what the Germans call ‘Tieg’. The starches will convert even when not ground to flour. A fine crush was OK when I did set it and forget it single infusion but not with my continuous recirculation. I base this on a study by Rock Bottom breweries and Darcy’s Law.

The thin mash is based on Kai Troester’s research. The pump setting is based on trial and error over several brew days.

I should also mention I use a Hockhurz style mash. I use 145*F for 30 min, 150*F for 30 min, 160*F for 45 min, and mash out at 170*. I pump crystal clear sweet wort into the boil kettle.

I get very consistent predictable results with this setup on my system. I believe each system is unique and requires an individual setup.

 

[RM-MN]

Brewbama has good suggestions for a continuous recirculation but with the coarser crush needed it will take more time and likely lower efficiency than a fine crush with no circulation. He mentions clear wort. Clear beer is my objective, not necessarily clear wort. The two aren't related.

 

[brewbama]

Brewbama has good suggestions for a continuous recirculation but with the coarser crush needed it will take more time and likely lower efficiency than a fine crush with no circulation. He mentions clear wort. Clear beer is my objective, not necessarily clear wort. The two aren't related.

I get good mash efficiency (routinely 92 plus or minus 2) using the Hochkurz style mash steps, what most would consider a course grind and thin mash along with a consistent pump output valve setting.

The clear sweet wort is a byproduct, not the primary objective of mine. I only mention it because it is remarkable to watch the cloudy wort at the beginning of the first step progressively turn brilliantly clear by the end of the mash out.

 

[Turfgrass]

I get good mash efficiency (routinely 92 plus or minus 2) using the Hochkurz style mash steps, what most would consider a course grind and thin mash along with a consistent pump output valve setting.

The clear sweet wort is a byproduct, not the primary objective of mine. I only mention it because it is remarkable to watch the cloudy wort at the beginning of the first step progressively turn brilliantly clear by the end of the mash out.

What are your formulas for calculating mash and sparge volumes? I use to letting the software do it.

Wondering if BS3 will allow you to change the grist ratio??

 

[brewbama]

BS will let you change the ratio. It’s what I use.

My basis is trial and error coupled with Kai Troester’s website.

http://braukaiser.com/wiki/index.php/Infusion_Mashing

“If direct heat is used aim for a mash thickness of 3.5 – 4.5 l/kg (1.75 – 2.25 qt/lb). This is the mash thickness that is commonly used in Germany and it makes stirring the mash during the heating phases much easier.”

And

“... enzymes and gelatinization also work better in a thinner mash.”