A few months back I wrote about my initial foray into all-grain homebrewing, building out my mash tun and recommending John Palmer’s How to Brew (which served as motivation to start all-grain brewing). I now have two batches under my belt (both otherwise-identical Porters), and I wanted to highlight this bit about the “batch sparging” method I’m using:
Palmer’s How to Brew outlined “batch sparging”—also the “no sparge” method—which made it clear to me that all I really need is the mash tun, no complications needed. Batch sparging is simple: you mash the grains with the hot water, drain off the hot wort, pour a second “batch” of hot water into the grains, and drain that off. Done. No need for a second tank setup and sparge arm assembly!
One detail I overlooked: when using this batch sparging method, you have to account for your recipe differently than for the standard method of continuous sparging. In particular, you will need more grains.
Palmer mentions this but it was a detail I had overlooked at first: standard recipes assume a points per pound per gallon (ppg) extract of about 36 for all-grain brewing, whereas batch sparging yields 28 ppg. This lower number means you’ll need to add more grain to your recipe to hit your target gravity (because you’re extracting less sugars from the grain).
I figured this out the hard way, of course (if making beer to drink can really be considered “hard”!): my first batch of beer was a Porter (based on a clone recipe I found of Deschutes Black Butte Porter) and, following the standard recipe grain amount, came in low on my original gravity. Puzzled, I fiddled around with the numbers and re-read the section on batch sparging in How to Brew, and realized the mistake—28 vs. 36 ppg.
However, Palmer gives detailed calculations for batch sparging wherein you plug in the standard amount of grain the recipe calls for, add your other inputs (batch size, target gravity), and you’ll get the adjusted numbers you need for grain amount (as well as volume of water for the mash and expected gravities of the runnings).
I built this calculation into a spreadsheet and adjusted my Porter recipe according to it, and brewed it again: this time I was within .004 points of my target original gravity. I was convinced; the proof, as they say, is in the pudding.
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