Batch Sparging
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.
For anyone interested in batch sparging for their all-grain process, Palmer’s calculations are an essential tool to have. So much so, that I’m going to try putting together a browser-based (Javascript) version that I’ll publish next week.
5 Comments to “Batch Sparging”
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A lot of your efficiency issues could have something to do with the quality of the crush of your grains, the thickness of your mash, loss areas in your system, mash pH, and many other potential areas.
There’s a great thread over at Homebrewtalk that outlines methods for maximizing your batch sparge efficiency….but most important, in my opinion, is knowing what to expect with your system! Once you get a good feel for what your efficiency will be with your system, you can adjust recipes as you need to fit the OG that you want. Cause let’s face it…adding 2lbs of grain to a recipe is pretty cheap over all.
At the end of the day, though, if you miss your numbers you’re still making beer!
I never hear anyone talk in “ppg” for the amount of extract they are collecting, (usually it is referred to in % extract efficiency) but I get 75% using batch sparging, which is what most recipes are calculated for. All of the recipes in Brewing Classic Styles are calculated for 70% efficiency, and Jamil is fly sparging for those. Batch sparging isn’t necessarily any lower in efficiency than fly sparging. The key to hitting recipe numbers is to know what % the recipe is calculated for, what % your process yields, and then adjusting your grist quantity accordingly.
The “ppg” (points/pound/gallon) is the extract potential, in terms of calculating gravity.
Batch sparging has a lower extract potential because the sugar-rich wort isn’t (necessarily) uniformly rinsed out of the grain, like a continuous sparging setup is. Not to say the conversion efficiency is any worse—I believe Palmer’s batch sparging calculations are based on a 75% efficiency assumption—but that the technique itself is where the reduced potential of the yield can be traced to.
[...] week I talked about the batch sparging technique as presented by John Palmer’s How to Brew, and noted that because of the loss in extract [...]