Mash Tun question

[capt82]

Been brewing AG a few years and moved from 5 gallon batches to 6.5 gallon batches and now my 5 gallon mash tun is now too small. I have a spare 7 gallon kettle I can easily make a false bottom for. This 7 gallon kettle is 11" wide and 16" high. It looks to me like I should have no problem fitting a 12-14 lb grain bill and a water ratio of 1:33.

I was thinking that the 11" X 16" kettle is pretty narrow/tall and would compact my grains too much giving me stuck sparges. I don't know how tall my grain bed would be with this but I thought I read somewhere that 11" grain bed was maximum to avoid a stuck sparge.

Can anyone confirm or deny? Thanks

 

[kh54s10]

I can't confirm or deny for sure but I think it has more to do with the ingredients, like wheat, oats, and rye etc. They make a dense mash that the wort has trouble passing through. I use a 10 gallon water cooler mash tun and have nearly maxed it out several times. It has approximately the same height to width ratio and I have not had any stuck sparge issues.

IMO, I would skip messing with the kettle for a gain of only 2 gallons. You will also need to consider heating or insulation to hold a steady mash temperature. It could get more expensive than you expect. Though it would be better than your 5 gallon tun. My ten gallon tun has handled 21 and 22 pound grain bills.

 

[jtratcliff]

Ditch the mash tun and BIAB in your boil kettle (10+ gallons, yes?)... use your spare 7G for dunk sparge if needed...

I do 6.5G batches in a 10G kettle 11-13lbs of grains, 7 gallons of water... 1.5 gallon dunk sparge in extra kettle.

No worry about stuck sparge...

 

[Singletrack]

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[capt82]

Ditch the mash tun and BIAB in your boil kettle (10+ gallons, yes?)... use your spare 7G for dunk sparge if needed...

I do 6.5G batches in a 10G kettle 11-13lbs of grains, 7 gallons of water... 1.5 gallon dunk sparge in extra kettle.

No worry about stuck sparge...

I knew someone would say BIAB... I tried and can not get efficiencies that are consistant. It always ranges from 55% to 70% at best. Very hard to stick the recipe when you don't know how its going to turn out.

 

[hottpeper13]

I knew someone would say BIAB... I tried and can not get efficiencies that are consistant. It always ranges from 55% to 70% at best. Very hard to stick the recipe when you don't know how its going to turn out.

Thats strange, when I went to BIAB for 6.5 gal batches my efficiencies stayed the same at 80%. SQUEEZE the piss out of it!

 

[jtratcliff]

Yup... Crush 'til you're scared, then squeeze like it owes you money.

Biggest efficiency issue with BIAB is crush IMHO... You can crush much finer, mash at 2+ qts/lb, and squeeze to get lower grain absorption...

My consistency is pretty good at 75-80% but I can see how if you're ending up all over the place (and low), it could put you off.

But it probably is the best way to repurpose your existing equipment without buying something.

 

[jtratcliff]

Depends on how much of a cheap-ass you are... I'll pinch a penny 'til it squeals like a pig, so personally, I'd try tweaking BIAB but other priorities may lead to other courses of action 😁

 

[capt82]

Thanks jtratcliff,
Although you inspire me to give BIAB another go someday (I do like the time it saves), my mash tun/sparge has always given me better results. I've double crushed, squeezed, and increased the soak time, idk.

I'm not getting a lot of hits on the grain bed height question. I may just have to try it and see what happens. My last year of brewing has been BIAB and I'm over the poor results I got. I just don't want to experiment anymore with my efficiencies.

 

[laredo7mm]

...I'm not getting a lot of hits on the grain bed height question...

I don't know what recommendations are floating around out there for grain bed height, but I brewed a RIS in my 10 gallon cooler mash tun not too long ago and didn't have any issues with draining the wort or with my batch sparge.

I don't know how deep the grain bed was but it was 26.6 pounds of grain with 31 quarts of water so the 10 gallon cooler was about 1/4" from the rim.


As for your 5 gallon mash tun, why is it too small to to 6.5 gallon batches? If you batch sparge, you can do two sparges as opposed to one. You might have to thicken up your mash a bit to fit your strike water and grain bill in the 5 gallon tun, but I was at 1.16 to 1 with that RIS and I didn't have any issues.

 

[capt82]

"You might have to thicken up your mash a bit to fit your strike water and grain bill in the 5 gallon tun, but I was at 1.16 to 1 with that RIS and I didn't have any issues".


laredo7mm,
I've used 1:25 to 1 and fought stuck sparges. I increased that to 1:33 and it helped. Would lowering water/grain ratio affect efficiency?

 

[jtratcliff]

Thanks jtratcliff,
my mash tun/sparge has always given me better results. I've double crushed, squeezed, and increased the soak time, idk.

Well there ya go, then. Stick with what works best for you...

Would lowering water/grain ratio affect efficiency?

I think thicker mashes can have efficiency issues... The absolute number is less important than to be able to hit the same number consistently, though. If you can consitently hit 60%, make it up w/ $2 worth of 2-row

One of the noted benefits of BIAB is that the thin mash should allow better extraction...

And being able to reposition the bag helps avoid stuck sparge...

as for grain bed depth, Palmer cites up to 18 inches in How to Brew :
http://howtobrew.com/book/section-3...-lautering/getting-the-most-from-the-grainbed

 

[RTL]

Grain bed depth is irrelevant. I've done 70lbs of grain in my 45 gallon MT with no issue which was close to 20" deep at 1.5:1. I've done 20lbs of grain on my old system at 1.2:1 and stuck like a beotch. It's all about crush and water:grist in terms of sticking. I also wet condition my malt now before milling. The only impact the ratio will have on your efficiency related to how much sparge water is left over and how long you want to boil. If depth was an issue then commercial brewery mash tuns would be enormously wide and short, which they are not.

 

[mrveeno]

I have this at the bottom of my 60 Qt Ice Cube cooler. It is PEX tubing and a large grain bag zip ties over the nipple. I get no grain at all, and it would be pretty much impossible to stop up. I put a plastic cutting board on top of it so the mash paddle doesn't grab anything. I also drilled holes in the lid bottom for sparging and run the sparge water into the top. When I had a round cooler for 5 gallon batches, I had a 6' coil of hard vinyl tubing with holes drilled in it.