I’ve read that in order to perform an ideal batch sparge, one should collect his pre-boil volume of wort from two (fairly) equal run-offs. Since I have a 5-gallon MT, I run into the problem of not having enough room in the tun to get enough volume from the first run-off. For example, if I mash in 12# of grain with 3.5 gallons of water, I only have enough room for about a half gallon top-up at the end of the mash. So my run off is about 2.5 gallons. That means my batch sparge needs to be 4.5 gallons to acheive a 7 gallon pre-boil volume.
So…how important is the “2 equal run-offs” rule? Should I just drain the mash and do two equal sparges? Is there some other way (that doesn’t involve me buying a bigger mash tun)?
The “equal runoff” may be the “ideal” but even if they’re unequal, it’s not going to make all that huge a difference. You might get slightly lower efficiency but, as long as you’re consistent, you can account for whatever efficiency you regularly achieve.
That said, if 3.5 gallons is all you can get in your cooler with 12 pounds of grain, that comes out to 1.167 quarts/pound. That puts you at the lower end of the range (thicker mash) of the normal 1 - 2 quarts/pound. Since at least 1.25 and probably, even better, 1.5 quarts/pound is an “ideal” ratio, you might seriously consider a new cooler. Get a cheap rectangular 36 to 48 quart (or even maybe larger) cooler and use Denny’s “braid system” and you can have a brand new mashtun for very little money.
2 equal runoffs (1 drain, sparge, drain again) is how most everyone performs a batch sparge. 3 runoffs (drainings of the tun) is what could potentially incur a slight boost in efficiency. ;D
I guess I should have emphasized the “equal” runoffs part. So, to clarify (or confuse things further), 2 equal runoffs may give you a bit better efficiency than 2 close-to-equal (like within a gal.) runoffs. Doing a 2nd batch sparge (3 runoffs in total ) may give you a bit better efficiency than 2 runoffs. For me, it becomes a point of diminishing returns thing. If I my 2 runoffs are within a gal. of each other, there’s not enough difference for me to worry about equalizing them. And unless I’m using so much grain that I can’t fit all the sparge water in the tun at once, there isn’t enough gain in doing a second sparge addition for me to mess with it.
Thanks for all the replies, guys! I’ll do a little experiment with the next 2 batches, trying each of the methods. I’m really not concerned with super good efficiency (grain isn’t that expensive), but rather a smooth brewing experience that is fun.
The equal runoff theory also works when considering more than one sparge. Three equal runoffs of 2.25 gallons each is slightly more efficient than three completely different volumes. Denny is right, these are diminishing returns and just add more time to brew day. Things like crush and minimizing dead space are much more important.
For example, if I mash in 12# of grain with 3.5 gallons of water, I only have enough room for about a half gallon top-up at the end of the mash. So my run off is about 2.5 gallons. That means my batch sparge needs to be 4.5 gallons to acheive a 7 gallon pre-boil volume.
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Aren’t you forced to do 3 run offs? If you only have space for 4 gallons and run off 2.5 that means the next sparge you can only fit and run off another 2.5 gallons. If you are looking to collect 7 gallons based on above id to this:
Mash with 3.5 gallons and run off what I expect would be 2 gallons. Then do two batch sparges adding 2.5 gallons each time. The extra vourlaf and drain is extra work, but would will not lose time in your brew day if you start heating the other run offs while doing the sparges.
I thought the common method, and the one I use, is to mash in at your preferred grain to grist ratio, nominally 1.3 qts per pound. After draining, you do two equal size sparges (letting each rest ~15 minutes while stirring occasionally) to collect the rest of your wort. This is also the method that Kai describes in his article showing increased efficiency from equal size sparges.
Me, when I am not brewing a monster I usually batch sparge. I’m worried about how much water to add because my first step is to drain the mash tun into my kettle. Then I measure (dip stick, actually my mash paddle, calibrated) to see what I have then I add half the remaining, drain, then add what I need to hit my preboil volume. Don’t care if it’s precise, it’s close enough.
I’ve always understood the standard batch sparge to be what MDixon describes. Dough in, mash (wait), optionally add mashout water, vorlauf, drain, add water, vorlauf, drain, done.
Although some conversion could occur if temps are maintained during that time, I think the rationale for waiting a period of time after stirring is to allow sugar diffusion from the husks and for the husks to settle towards the bottom (and create an effective filter bed) before lautering is begun. I don’t wait 15 minutes either. I do wait about 5 and then open the valve a little bit, vorlauf, and then gradually open it up a little more to avoid grainbed compaction (10 gallon batches with an Igloo cooler).
Kai, what if you added your first sparge say 10 minutes before taking any runnings, would it have the same effect as a single batch no-sparge with a severe hit in efficiency?