I’ve been fly-sparging (continuous sparging) ever since I started brewing all-grain. I’d heard about batch sparging soon after I started brewing all-grain, and I’ve been wanting to give it a shot. I’m only getting about 75% efficiency on fly-sparging anyway, so if batch sparging makes an easier brew day, then why not just batch sparge? The caveat is that your efficiency is lower, so you just have to purchase an extra pound or so of grain. At a buck and a bit per pound, that’s no big deal at all.
I had a 50 quart Coleman XTREME5 cooler hanging around that I’d bought for camping about a year ago, and I found a good video on converting one of these exact coolers to a mash tun.
So Saturday I went up to Lowes and picked up all the parts. I built the mash tun in about an hour and left some water to sit for several hours to test for leaks. All good!
Ball Valve Mounted to Cooler
Inside of mash tun
And yesterday I brewed a “McRed Irish Bastard Ale.” It’s my own recipe and is very experimental. I gave batch sparging a shot.
A few mistakes I made when batch sparging
I didn’t calculate the thermal mass of the mash tun.
I assumed that this mash tun’s thermal mass would be a bit higher than the cylindrical 5-gallon cooler I’ve been using for mashing. So I heated my strike water a bit hotter, around 176F. After doughing-in, the temperature settled around 159F. Too hot. I was shooting for 151F.
So I added some ice and stirred, little by little. Each ice cube removed less than 1F. Eventually, I added some water to bring the temperature down quicker. Too much water. Temperature settled around 146F. Too cool.
At this point, the mash had already been sitting for about 30 minutes too hot as I tried to get the temperature down. I let it be at 146F for another half hour.
I then drained the first runnings out of the mash tun, recirculating the first 2 quarts or so for clarity. I struck the second batch at 154F, and my temperature landed around 151F. Good. I let this sit for another 30 minutes and then drained again.
Pre-boil gravity hit about 1.037, which is just about right for this recipe.
I didn’t intend to do a multi-step infusion
Since my temperatures were so off (as above), I ended up doing a multi-step mash in the opposite order. I intended to do a simple single-step infusion mash.
Roughly, I mashed at about 158F for 20 minutes, then at 146F for about 15 minutes, then at 151F for another 30 minutes. Weird, but the beer is fermenting along just fine today.
I think this batch is going to turn out just fine but with a lot more body than I intended for this recipe, but I think it’ll be plenty drinkable.
I’ll try batch sparging again
Next brew, I think I’ll give batch sparging another shot. This time, I know my tun’s approximate thermal mass, so I should have a much easier time hitting my mash temps.
All in all, batch sparging is much easier than fly-sparging, and my efficiency is nearly the same. Why not make things easier?