Ever since I moved from extract brewing to all grain, I have used the same Rubbermaid ten gallon cooler for my mash tun. A Craigslist find, it came to me with a bazooka tube, which worked only marginally well from the get-go. Stuck sparges were common, and then there was an ill-fated Russian Imperial Stout brew day when I managed to knock the bazooka screen loose while stirring twenty-four pounds of grain. Not good. Enter the false bottom. I ordered a domed false bottom, and my next few brew days were a huge improvement. My efficiency immediately improved and no more stuck sparges. Problem solved. Or so I thought.
Funny thing was, I eventually had several more stuck sparges. Not every time, though. Ten gallon batches were more likely to get stuck, but five gallon batches would also stick occasionally. I tried loosening the gap on my grain mill, but a coarser grist didn’t correct the problem.
After much thought, I think I may have may have finally found the cause of the problem, but I won’t know for sure until can test out my solution. I’ve been using a short section of 3/8″ silicone tubing to connect the false bottom to the hose barb that connects to the valve on the mash tun. This makes it really easy to install and remove the false bottom, but I suspect that the tubing is collapsing under the weight of the grain once enough wort has drained out and the grain bed begins to settle.
I made a quick sweep of the odd plumbing fittings I had on hand and ended up with a short section of 3/4″ PEX tubing. The PEX is rigid enough that it shouldn’t collapse as easily as the silicone tubing. The silicone tubing fits inside the section of PEX, which is short enough still allow the false bottom to be easily removed for cleaning. The finished product looks like this:
I can’t wait until my next brew day to see if this corrects the problem. Stay tuned…