extreme ice chest mlt with 5 row copper manifold

[brewrench]

Hey everyone just wanted your thoughts on my mash tun. Like the heading says I have a coleman extreme rectangular ice chest. I built a 5 row copper sparge manifold that is full of slits that face down. I know there is a lot that goes into mash eff. but mine seems to be low. Just curious if anyone has any experience with this type of mash tun. I would appreciate any info. Thanks

[BrewerAdam]

I have a 48 qt rectangular coleman cooler with a cpvc manifold (5 inches wide, 12 inches long, and 4 cross bars with the middle two only having cuts in them) and consistantly get 75% to 80%. Your cooler dimensions/manifold are probably not your problem unless it is some crazy weird configuration.

I would look at your crush, sparging technique, mash temps, etc as the possible problem.

What is your efficiency now?

[Kbar]

What efficiencies do you get?

What is your sparge technique?

I get 65-70% with a rectangular cooler, and a 3 arm Zymico screen setup, batch sparge and RIMS system.

[brewrench]

I'm not sure what my efficiencies are because I havent taken the time to do the calcs My manifold is basically 5 pieces of copper that run the length of the cooler and are connected at the ends and exit through the center piece of copper to the valve. Right now I batch sparge, let it sit for an hour at 152, slowly drain till empty then refill ,stir and drain till I hit my boil volume. Thanks for your replies, I appreciate it. I figured it was not my mash tun but I just wanted to see what other poeple were getting so I could rule it out. I'll spend some time on temp and crush. I think I may have a problem with both.

[scotchpine]

I just made a 3 row copper manifold for my 28qt cooler tun for the same reason. I still just have to cut the slots in it yet. I have been using a 30" SS braid, but as it is only attatched at the exit valve, I think it may be getting pulled up form the bottom as I stir the mash. I also just got a grain mill for Xmas so controlling my crush may help as well. I may use the braid this next time with my first self crush so I will know which change makes the difference, if any.

[brewrench]

I need to get a grain mill after I finish my brew stand. I was at my lhbs which is owned by my buddy the other day milling grains and he yelled at me for closing the gap on the mill for a finer crush! Great idea of sticking with the braid on the first batch. It will definately help track the changes you make.

[brewrench]

Well I figured out my problem with my efficiencies. Temp, temp, and more temp. My thermos were reading 6 and 8 degrees high. So when they said I was mashing at 152 I was really mashing at 144-146. Not all that great for conversion. Thanks for your ideas guys.

[Kbar]

Help me out here - you stated that your eff were too low due to a lower than expected mash temp?

In my rookie mind, you mashed more so in the Beta-A range making a more fermentable wort. Other than a viscosity gain at 6-8F higher, how are his eff's affected?