experimental manifold design

[mothership]

so, awhile back i upgraded to a 10 gallon system. coupled with that system i built myself a stainless steel manifold for my 10 gallon rubbermaid cooler. ever since then, i seem to be getting (according to brewsmith) 80-90% efficiency. this seems a bit odd to me. my technique has not changed, only my equipment and volume. so i'm wondering if my efficiency has something to to do with my manifold. could it be that i stumbled upon a great design? i would like to make another, identical to what i have, and have someone else try it out. any takers?

 

[williamnave]

Is it the same mash tun, just a different manifold? I don't have a ton of experience but I've talked to a lot of people who get higher eff. when the mash tun is at near max capacity.

 

[Ovidsmuse]

Did you also get any new thermometers? Were you having problems with hitting your mash temps in your old setup? Manifold design could help increase efficiency if you were losing sugars to dead space or if you were getting channeling, especially when the water just runs down the sides instead of through the grain bed. Do you batch or fly sparge?

 

[sdbrew1024]

I am experiencing the same thing. I was doing 5 gal batches in a 10 gal cooler and was getting ~70% efficiency. I moved to 10 gal batches, didn't change anything about my equipment and now get ~85% efficiency. My numbers have been stable over 10 batches or so, so at least it's consistent.

 

[Ovidsmuse]

sdbrew, my guess is that you were losing heat to the extra head space and may have had too short of a grain bed. Do you batch or fly sparge?

 

[sdbrew1024]

I batch sparge. With 5 gal batches I would lose ~3 degrees over a 60 minute mash, with 10 gals I still lose 1-2 degrees. I don't really care that my efficiency changes, as long as it stays constant for a given batch size...

What do you mean by too short of a grain bed? If I had this problem wouldn't most other people doing 5 gal batches in 10 gal coolers also have it?

 

[Golddiggie]

What's your water:grain ratio?? I've been getting 78-82% efficiency with BIAB using 1.5-2qt/# of grain... Of course, that could all go down the drain since I'm about to use my MLT cooler (70 quart Coleman Xtreme)... I plan to use the same water:grain ratio though, and see what I get over the next few brews...

 

[Ovidsmuse]

Read this, I know this isn't as current as the latest book release but is still informative.
http://www.howtobrew.com/appendices/appendixD-2.html

Grain bed height is important to the way water is drained, even when you batch sparge this can make a difference.

 

[mothership]

Is it the same mash tun, just a different manifold? I don't have a ton of experience but I've talked to a lot of people who get higher eff. when the mash tun is at near max capacity.

when i changed from 5 gal batches to 10 gal, i went from a rectangle cooler to a 10 gal round rubbermaid. so it's a new cooler. i get the same eff. whether i do a 5 gal batch or 10 gal batch. sometimes i only have enough time or grain for a 5 gal batch. i flysparge everytime. in fact, i've never tried any other method. for a 10 gal batch, i sparge for 2 hours and 1 hour for a 5 gal batch.

no new thermometers. my sparge water is usually around 180-190 in order to keep the mash warm enough (it's cold in ne washington). i don't use a sparge attachment, just a hose comming off the HLT

i think my water:grain ratio is 1:1.25. whatever the standard setting is in brewsmith. i just do what the computer tells me to do

here's a picture of my manifold. there are slots cut on the underside of the tubes:

 

[Ovidsmuse]

I think you are just getting less channeling, the distance between the side of the cooler and the manifold looks good and having the slits on the bottom means there is very little dead space. This could explain a 5-10% increase in efficiency and the deeper grain bed doesn't hurt either. How big was your old cooler, and do you have pictures of the old manifold in it?

 

[Golddiggie]

I would adjust your water:grain ratio and see if you get better mash efficiency. Try 1.5qt/# for the next batch. That is, if your MLT can handle the extra volume.

For the manifold, the straight piece is only joined at one end, right? Not sure about this, but might have been better to join that to both sides of the octagon...

 

[mothership]

the old cooler was a small rectangle one with a single tube running the length of the inside of the cooler. slots were also cut in the underside of it. with that old setup, i was getting ~60% eff.
i realise my new manifold is a bit better in term of collecting sugar from a wider area (less channeling) i'm just surprised i'm get 80+% eff

if i make a duplicate manifold, anyone willing to try it out in their system?

 

[mothership]

here's a pic of my old mash tun, but sorry, no pic of the filter

https://picasaweb.google.com/lh/photo/9aIeyJwu25EbFRYA90WRgg?feat=directlink

 

[mothership]

I would adjust your water:grain ratio and see if you get better mash efficiency. Try 1.5qt/# for the next batch. That is, if your MLT can handle the extra volume.

For the manifold, the straight piece is only joined at one end, right? Not sure about this, but might have been better to join that to both sides of the octagon...

yes, i would have been better to join both ends of the strait piece. the strait piece was an afterthought

my eff with this setup is ~80-85%. not complaining, just curious that it's so high

 

[Golddiggie]

I would try it out, but I don't think it would work (as designed) with my Coleman 70qt cooler...

 

[mothership]

I would try it out, but I don't think it would work (as designed) with my Coleman 70qt cooler...

no, my design wouldn't work in a rectangle cooler. however, i modified version would (wheels in head turning...)

 

[Golddiggie]

If you want to make something up for me to test out, I'm willing... Just make it so that I can just join it to the silicon tubing where the bazooka connects (1/2" silicon tubing there)...

 

[mothership]

my manifold has a female 1/2" NPT on the end. would that work? thinking maybe you could screw in a 1/2" barb fitting into the 1/2" NPT and connect your tubing.

also, what are the inside dimensions of your cooler?

 

[Golddiggie]

I have the tubing connected to a barb on the bulkhead side (1/2" fittings)... Bottom of the cooler is 10"x24"

If you could put a short 1/2" barb on the out end of the manifold, that would work... Tubing stops at ~6" from the side of the cooler... Don't want to cut the tubing, so that I can use the bazooka later if I want to...

 

[Snowhere]

I would be willing to bet your enhanced efficiency has a lot to do with you going to a round cooler along with your manifold. With your new skinnier MLT, you get a thicker grain bed which helps with your sparge water to wash more sugar out. You end up with a higher head pressure to push the sugar out of the grain bed as opposed to the rectangular cooler. The octagon design is suggested in the how to brew book if you are going to do a manifold, so I believe it is a good design. Optimum spacing is around 0.7 of the diameter of your mash tun and this does apply to both the round and rectangular coolers. I use a round 10 gallon with a false bottom and I would be disappointed if I ever get less then 80% efficiency. I average 85% with fly sparging and I do like higher gravity beer!

 

[mothership]

thanks for the info snowhere