As some of you may know, I brew small batches. When I originally decided to do so I bought a small 2 gallon Coleman Stacker cooler for use as a mash tun:
I have regrettably only been able to do one AG batch with it, but have done 4 test mashes (mash, no ferment) to try and dial it in. The first test mash efficiency was poor (~56%). I adjust my crush and stirred better for the second test mash and got it into the mid 60s for efficiency. By the time I brewed my small batch BDSA, I managed a respectable 74% efficiency.
One thing I didn’t like about my original configuration was the steel braid configuration:
I decided last week that if time permitted I would change it out to a single outlet, short piece of braid. I removed the old setup and tried to brace the opening with a washer/PVC ring/smaller copper ring arrangement:
When it was all said and done I did not get the seal I wanted. I have not leak tested, but feel confident I’ll need to remove the original rubber seal that came with the cooler and put something else there. Everything on:
Anyone know of something from the big box home improvement stores that I can use to make a better seal? Not sure if they carry the normal locknut/Oring setup common in homebrew equipment.
You might be able to get away with a piece of silicone, maybe an old oven mitt or trivet, cut to size of the washer. I’ve seen the seal on both sides, but I imagine the inside is best in order to keep liquid out of the insulation.
But I would try to do it the right way with a ring and locknut. Bargainfittings.com
I don’t have anything helpful to add about improving the seal but I can speak to the efficiency issue. I use the same cooler on my small batch setup and used to have really awful efficiency. I extend all mashes to at least 75 minutes (sometimes 90 for drier beer styles) and get upper 70s to upper 80s in efficiency. Might be worth giving a try.
Yeah not sure why this is. Mine holds temp pretty well (< 2 deg/hr). I fine tuned my crush and got to the low 70s. I’m going to test once with the new setup and then take your advice.
You can always go low-tech if you are unable to obtain a solid seal. I used a rubber stopper, a length of copper tubing, a length of clear PVC tubing, and one of the large white plastic hose clamps that one can purchase at a home brewing supply shop on my mash tun for the better part of the first decade that I brewed (pragmatic brewing used to be much more popular than it is today). The length of copper is inserted into the rubber stopper such that tubing sticks out of both sides of the hole. The length of PVC (or silcone) tubing is attached to the end of the copper tubing that is on the small side of the stopper. You should leave the gasket from the original valve on the cooler, and insert the stopper into the hole such the small side is facing out (the hot mash will make the fit even tighter). The hose clamp is used as a valve with discrete settings on the outside of the tun. I used another piece of tubing that was attached to a Phil’s Phalse Bottom on the inside of the tun, but you can attach a braid as well.
Efficiency is more about the crush than anything else. That and collecting every drop of runnings. I’ve been a small batch brewer for many years, anything between 1.7 gallons (current) and 3 gallons (past). For a while I was consistently seeing efficiency right at about 90%. A couple of years ago I decided to back off on crushing so hard and purposely shoot for low 80s for efficiency because I feared it was becoming less grainy due to the little grain required compared to everyone else, with comments from judges that the malt character was lacking. So that’s where I’m at now, low to mid 80s max efficiency. I can pretty much dial it in wherever I want based on how hard I crush. So can you probably.
Oh, and uh… I only mash for 40-45 minutes. Mash time isn’t a huge factor on efficiency above that point, based on my own experiments.
I’m going to fix it up this weekend. I’d like to get one more AG batch in before winter hits Central NY. I’ll more than likely do some extract batches over the winter.
