Hello, Double Batch Sparge

I have been having troubles with my efficiencies since I began all-grain brewing roughly 8 months ago. During this time I was doing single batch sparging and hitting 60-65% efficiencies. After talking with a local brewer, he recommended I try double batch sparging or fly sparging. Since I dont quite have the equipment yet for fly sparging I chose to do try double batch sparging first.

Yesterday, brewday of a big milk stout yielded me with an 84% efficiency! A 20%+ jump, which I am very satisfied with. All mechanical variables were the same as prior mashes with the exception conducting a double batch sparge vs. single batch sparge.

So, if anyone is having trouble with low efficiencies and has not tried to step up to a double batch sparge - it's a must! Don't wait as long as I did

Did you just split your single sparge water volumes in half for a double sparge

It's baffling to me how this happens for some and still others (such as Denny) have experimented with it heavily and saw no appreciable increase in efficiency with double-batch sparging...

The same thing happened to me. I was consistently hitting 60% on the dot with a single batch sparge. When I split up my sparge water I immediately started hitting 80-85% on each batch.

My last two beers I have gone to a single batch sparge. I have noticed I lost about 10% on each batch. I thought I was just doing something wrong. I think next time I'll go back to a double batch sparge and see what happens.

I don't understand how this could be possible.

Each subsequent sparge will extract less and less sugar; to suggest that efficiency can increase 20-25% with a second sparge sounds just plain crazy to me. I don't have my numbers in front of me, but I always measure the gravity of my first and second runnings, and on "normal" 5-6% ABV beers (pale ales, ESBs, and the like), I'm pretty sure my second runnings are in the 1.012 range. Yet another sparge wouldn't get me much more than about 1.006, which is almost pure water at that point.

I used to double-sparge, but saw maybe a 3-4% difference in efficiency. Since I typically get about 75% with a single batch sparge, I see no reason to double it.

tre9er said:

It's baffling to me how this happens for some and still others (such as Denny) have experimented with it heavily and saw no appreciable increase in efficiency with double-batch sparging...

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I'm in this boat as well. I went to a double batch sparge and am still only at around 65%. I'd love to take the time to pick it apart and see why I'm only hitting that.

Who said 20-25%? 4-5% is typical. If one gains more than that, it causes me to consider the longer rest times and ramped temps are completing what is normally incomplete conversion.

I also always get 72-75% using a single batch sparge on a typical recipe. Tried double sparge on two different batches and yielded about 2-3% better efficiency. About the same increase I observed with fly sparging. Wasn't worth it so I went back to single batch sparge.

Another reason I don't do double sparges is that the pH starts to climb to a level that can start extracting unwanted tanins from the grain bed (unless you adjust the pH of the sparge water).

However, I'm going to throw a second sparge in my next brew (an AB Jr Rebrew) and collect separately just to see how much I get.

One other factor to consider is deadspace. Since batch sparging works on the principal of dilution of the trapped wort in the grain (absorption) it also applies to wort trapped below the drain height. Conclusion: multiple batch infusions will show a greater efficiency gain the more deadspace you have.

Some mash tun designs have a lot of dead space. if this volume isn't known and made up for, double batch sparging can seem to make a huge difference in mash efficiency, when its really flushing lost wort through the system.

Single batch sparging works very well for me.

@Steber
I did split the sparge into two equal additions, I believe both were 10.4 qts.

I measured my mash tun deadspace to be 2.8 qts, which I accounted for in the sparge. Pretty soon though I am going to do a double brew day with two identical grain bills and do single vs double batch sparge. I am planning on it being 65% & 84%, so it will be an American IPA & Imperial IPA, respectively. I'll collect the identical amount of wort & take a preboil refractometer reading. Anyone interested in hearing back the results?

Over last 20 years, I've done both and see about 5 points difference. My guess, with all respect to poster, is that he did a stout and the mash Ph may have been right and it jacked up the efficiency. This is a guess of course

IMO Efficiency is most impacted when batch sparging by (in order)

Crush
Ph
Mash time
Sparge technique/system

This all assumes.your measurements are right and thermometer is calibrated.

tre9er said:

It's baffling to me how this happens for some and still others (such as Denny) have experimented with it heavily and saw no appreciable increase in efficiency with double-batch sparging...

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Yeah, I'm totally baffled. I can only assume that if you get that much increase from 2 sparges that you must be doing something wrong!

asdtexas said:

Over last 20 years, I've done both and see about 5 points difference. My guess, with all respect to poster, is that he did a stout and the mash Ph may have been right and it jacked up the efficiency. This is a guess of course

IMO Efficiency is most impacted when batch sparging by (in order)

Crush
Ph
Mash time
Sparge technique/system

This all assumes.your measurements are right and thermometer is calibrated.

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I applaud you!

I routinely hit 75% brewhouse efficiency with the usual Denny batch sparge method, and this is using my LHBS's grind. I often do the 1 gal or so (depending on whats called for) boiling infusion for a mahout attempt, but I wonder if that's even completely necessary.

Double batch sparging? Nah... Sounds like more work than just batch sparging, which helps keep me lazy... Or pragmatic as I've heard it called.

I have only done two all grain brews and have hit 65% on the first and 64% on the second using a single batch sparge. I used 65% on my recipe so it hasn't been a problem but I would like to get closer to 75% as long as I don't have to get crazy. On my first batch (12.5lbs grain bill) I got 1.060 on my first runnings (3.75g strike-2.25g drained) and 1.020 on my second runnings (4.25g sparged). I wonder if I could benefit for a double sparge? It doesn't seem like it should improve much from doing so but maybe there's something in my process that would benefit from a double.
I'm using a rectangular cooler with a PVC manifold. Wonder if that could make a difference?
I'll try a double next brew day and see what happens.

duckmanco said:

I routinely hit 75% brewhouse efficiency with the usual Denny batch sparge method, and this is using my LHBS's grind. I often do the 1 gal or so (depending on whats called for) boiling infusion for a mahout attempt, but I wonder if that's even completely necessary.

Double batch sparging? Nah... Sounds like more work than just batch sparging, which helps keep me lazy... Or pragmatic as I've heard it called.

Click to expand...

Being....er.."pragmatic" I decided I wanted to find a way to skip that pre mash run off addition. I simply started using a higher mash ratio, like 1.6-2 qt./lb. Works great, may have even increased my efficiency a bit, and saved me a step!

Dilligaf76 said:

I have only done two all grain brews and have hit 65% on the first and 64% on the second using a single batch sparge. I used 65% on my recipe so it hasn't been a problem but I would like to get closer to 75% as long as I don't have to get crazy. On my first batch (12.5lbs grain bill) I got 1.060 on my first runnings (3.75g strike-2.25g drained) and 1.020 on my second runnings (4.25g sparged). I wonder if I could benefit for a double sparge? It doesn't seem like it should improve much from doing so but maybe there's something in my process that would benefit from a double.
I'm using a rectangular cooler with a PVC manifold. Wonder if that could make a difference?
I'll try a double next brew day and see what happens.

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Try a finer crush first, or run it through the mill twice. That's more likely to increase your efficiency.

Denny said:

Being....er.."pragmatic" I decided I wanted to find a way to skip that pre mash run off addition. I simply started using a higher mash ratio, like 1.6-2 qt./lb. Works great, may have even increased my efficiency a bit, and saved me a step!

Click to expand...

I've been doing this as well and am usually in the mid 70's for BH efficiency. I'm still dialing-in my loss factors with a new system, too.

Denny said:

Being....er.."pragmatic" I decided I wanted to find a way to skip that pre mash run off addition. I simply started using a higher mash ratio, like 1.6-2 qt./lb. Works great, may have even increased my efficiency a bit, and saved me a step!

Click to expand...

Really??? No attempted mashout using the gal or so of boiling? I'll be sure to give this a shot next go round. I've been doing every beer under 1.050 as a no sparge, but leaving the final 2 gal as a boiling infusion to hit mashout and have seen 75% efficiency with ease. Thanks for the info Denny. I'm helping a buddy go AG this weekend with a trip to the local for tubing and the valve for the mashtun.

Well... Tried the double batch sparge today on a Pale Ale. Got the same $hitty efficiency I always get. 3.75g strike water. First runnings: 1.75g @ 1.084 corrected. Second runnings: 2g @ 1.056 corrected. Third runnings: 2.25g @ 1.023. Per boil was 1.051 corrected. At 65% efficiency I should have gotten 1.053. Guess I'll stick to single sparring and start warming up SWMBO to buying a grain crusher.

Dilligaf76 said:

Well... Tried the double batch sparge today on a Pale Ale. Got the same $hitty efficiency I always get. 3.75g strike water. First runnings: 1.75g @ 1.084 corrected. Second runnings: 2g @ 1.056 corrected. Third runnings: 2.25g @ 1.023. Per boil was 1.051 corrected. At 65% efficiency I should have gotten 1.053. Guess I'll stick to single sparring and start warming up SWMBO to buying a grain crusher.

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Try more water in the mash and a finer crush. Trust me

Tried a double crush this time and had the same results. Didn't bother with the double sparge. Going to try and cut my water with RO water for the next batch. It only makes sense that that would solve the problems since it makes a brew day more expensive.

Dilligaf76 said:

Tried a double crush this time and had the same results. Didn't bother with the double sparge. Going to try and cut my water with RO water for the next batch. It only makes sense that that would solve the problems since it makes a brew day more expensive.

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Have you ever cooled the hydrometer samples before taking them? The temp corrections make me nervous.

There's no reason you shouldn't at least get in the 70's with a good crush, tons of stirring at dough-in and before run-off, and enough hot water to get soluble sugar.

I have let my samples cool. Not down to 60* but closer than straight out of the mash.

My difference between single and double was about 5%, or in other words, not enough to make me want to double sparge. I was in the low 80s to begin with, so I just factor a slightly lower efficiency and add a bit more grain.

My efficiency jumps around a bit as my equipment and method is still evolving though. If I score low I just add boil time. Score high and add a bit of water to the boil.

Homercidal said:

My efficiency jumps around a bit as my equipment and method is still evolving though. If I score low I just add boil time. Score high and add a bit of water to the boil.

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This is where having a refractometer with ATC helps a ton. It's on my wish-list for sure.

tre9er said:

This is where having a refractometer with ATC helps a ton. It's on my wish-list for sure.

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Oh, yeah. I forget not everyone has one.

Okay I have been watching the forums for months, still can't figure out with SWMBO stands for. I know it basically means wife but what does it Stand for?

In before this one blows up and gets locked

drawdy10 said:

Okay I have been watching the forums for months, still can't figure out with SWMBO stands for. I know it basically means wife but what does it Stand for?

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I bet even a simple google search would turn up that result.

SWMBO

Say, What Makes Bacon Om-nommy?

She Wacked My B@//$ Off.