Mash and Sparge efficiency question

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Angus Young

Member
Joined
Oct 23, 2018
Messages
23
Reaction score
13
Location
Seattle
Hi guys,

I just brewed a pale ale with 10.5 lb grains, mashed at 153F for about 80 minutes. First run is 3.5 gallons at 1.070, then I batch sparged with 3.5 gallons of 190F water, grain temp was 168F during the Sparge. I ended up with 7.2 gallons at 1.048 in the kettle pre-boil. My question is am I losing efficiency during the batch Sparge or these numbers are normal for the method I am following? Beersmith says mash efficiency is %88.3 and I'm happy with that but just want to know more about batch Sparge efficiency.

Thanks in advance.
 
The efficiency in batch sparging is how well the sugar that was converted during the mash is rinsed off the grains. If you add the water and stir it up, you get more of the sugar. If you repeat the sparge you get even more but that is about the limit on what sugars you get without chancing raising the pH enough to extract tannins plus the little bit of sugar that you would get with a 3rd sparge will be costly in fuel as you have a very weak solution and need to boil off a lot of water to concentrate that sugar.
 
1.048 is putting you in the 80-85% range...
I don't batch sparge any more, but that seems pretty decent to me.
I agree with the statement above, if you're not stirring your batch sparges you'll probably get a few points by doing it.
 
Last edited:
You're fine. Your first runnings of course have a higher gravity reading than after the sparge because there is less sugar in the second runnings... and more water. Your gravity of 1.048 will go up again after the boil when some of that water boils off.
 
Need to know what your strike volume was in order to do a more complete analysis of your mash and sparge. Also, your volume numbers don't quite add up the way they should. If your first runnings were 3.5 gal, and you sparged with 3.5 gal, your pre-boil volume should have been 7.0 gal, since the grain is saturated at the beginning of the sparge, and should not absorb any additional water. You may not have drained the MLT as well on the initial runnings, or you have some measurement error. To maximize efficiency, you want to drain as completely as possible on initial run-off.

Brew on :mug:
 
Need to know what your strike volume was in order to do a more complete analysis of your mash and sparge. Also, your volume numbers don't quite add up the way they should. If your first runnings were 3.5 gal, and you sparged with 3.5 gal, your pre-boil volume should have been 7.0 gal, since the grain is saturated at the beginning of the sparge, and should not absorb any additional water. You may not have drained the MLT as well on the initial runnings, or you have some measurement error. To maximize efficiency, you want to drain as completely as possible on initial run-off.

Brew on :mug:
Hi Doug,
My strike water was 5 gallons around 164F. I think I used a bit more than 3.5 gallons for batch sparging, that's why ended up with 7.2 gallons in the kettle. I always mash with 1.75 qt/lb to get a bit more efficiency.
 
Batch sparge efficiency is typically a little lower, but its also much quicker. Worth losing the extra few % points in my opinion for the time savings.

Are you also doing a mash out by adding some boiling water at the end of the mash? Stirring gently when you mash in and mash out definately boosts OG. Just make sure to let everything settle and vorlauf.

I basically use Denny's process and it works great for me. My mash tun isn't insulated so I probably lose a little efficiency.

http://www.dennybrew.com/

In a ~1.050 OG batch with all base malt I get about 74% efficiency. If I add specialty malts or increase OG significantly I expect to lose efficiency.

88% efficiency is super high. Are you sure that's right?
 
Batch sparge efficiency is typically a little lower, but its also much quicker. Worth losing the extra few % points in my opinion for the time savings.

Are you also doing a mash out by adding some boiling water at the end of the mash? Stirring gently when you mash in and mash out definately boosts OG. Just make sure to let everything settle and vorlauf.

I basically use Denny's process and it works great for me. My mash tun isn't insulated so I probably lose a little efficiency.

http://www.dennybrew.com/

In a ~1.050 OG batch with all base malt I get about 74% efficiency. If I add specialty malts or increase OG significantly I expect to lose efficiency.

88% efficiency is super high. Are you sure that's right?
Hi there, thanks for your comment! I am not doing a mash out. Just mash and drain, single batch sparge and drain the wort. I am getting %88.5 mash efficiency because I recently bought a grain mill and I mill at 0.025 inch roller gap. I also condition the grains for 10 minutes before milling. It took my efficiency from %65 to %85.5. I will read Denny's process, thanks again!
 
Hi there, thanks for your comment! I am not doing a mash out. Just mash and drain, single batch sparge and drain the wort. I am getting %88.5 mash efficiency because I recently bought a grain mill and I mill at 0.025 inch roller gap. I also condition the grains for 10 minutes before milling. It took my efficiency from %65 to %85.5. I will read Denny's process, thanks again!

That's some serious efficiency! Nice work!

I'm doing 11g batches in a small Manhattan apartment, so conditioning the grain seems like too much of a PITA in my case. Cool to know it works though.

If you are grinding the grains that fine I would be wary of stirring as you may be susceptible to clogging issues, i.e. grain sneaking through the false bottom. I would stir gently and with care. You'll probably be fine, but just be careful.

Whats your mash tun and false bottom setup like?

P.S. nice username...Let there be Rock! And amazing beer!
 
I have a 10 gallon Igloo cooler with a false bottom. I stir a lot during the batch sparge and vorlauf until it runs clear. Never had a stuck sparge while I'm milling my grains very fine. I believe conditioning grains really helps. If you have your own mill, conditioning the grain is extremely simple and takes only 10 minutes. All you need is a spray bottle.
Thanks for the comment about my username, yes big fan of AC/DC :)
 
My mash efficiency jumped by 8 to 10% after I started malt conditioning and dropped my mill gap to .022" . Never had a stuck runoff either. Sounds like my process is the same as yours. I am also a lifetime AC/DC fan. Also LOVE Seattle. Lived there for 3 years back in the early 80's.
 
I have a 10 gallon Igloo cooler with a false bottom. I stir a lot during the batch sparge and vorlauf until it runs clear. Never had a stuck sparge while I'm milling my grains very fine. I believe conditioning grains really helps. If you have your own mill, conditioning the grain is extremely simple and takes only 10 minutes. All you need is a spray bottle.
Thanks for the comment about my username, yes big fan of AC/DC :)

Why do you vorlauf until the wort runs clear. All you need to vorlauf is until grain and husk pieces stop coming out. There is no relationship between clear wort and clear beer.
 
If I may add one thing about batch sparging in particular. When I used to mash indoors and boil on a Blichmann burner outdoors and had a Monster Mill 2 with a tighter than average gap setting my efficiency was a consistent 86%. With my new setup in an apartment my efficiency lowered, now have a Monster Mill 2 Pro, same gap setting but my efficiency has gone to 77%-83% mainly due to having less sparge water to use as my boil off in the Robobrew v3 is one gallon per hour less than what I used to boil off. Anyhoo, the point I want to add is when doing my new setup I went with a half inch ball valve on my cooler whereas I used to have the 3/8" valve. Denny recommends opening the valve all the way for maximum flow to set the grain bed quickly. I never did that before but this time went by that advice and personally I don't agree with it at all. I'm finding, at least with my 1/2" valve, that the runoff is too fast and compacts the grain bed in a negative way. As a result I'm seeing some wort still sitting in puddles after I've runoff. That means that wort isn't getting through the grain bed. I'm brewing tomorrow and will go back to slowing the flow like I used to and report back if that stops this from happening.


Rev.
 
Why do you vorlauf until the wort runs clear. All you need to vorlauf is until grain and husk pieces stop coming out. There is no relationship between clear wort and clear beer.
That's what I tried to say actually :) Thanks for clarification!
 
My mash efficiency jumped by 8 to 10% after I started malt conditioning and dropped my mill gap to .022" . Never had a stuck runoff either. Sounds like my process is the same as yours. I am also a lifetime AC/DC fan. Also LOVE Seattle. Lived there for 3 years back in the early 80's.
Rock on! I am pretty happy with my mash efficiency but while I have 7 gallons of wort in the kettle, I always end up with 5 gallons in the fermenter. Brew house efficiency is around %70. I am not even boiling hard, just a rolling boil to strip DMS and other stuff.
Seattle is the reason I became a homebrewer. Mostly because of the amazing beer culture and long dark winter days :)
 
If I may add one thing about batch sparging in particular. When I used to mash indoors and boil on a Blichmann burner outdoors and had a Monster Mill 2 with a tighter than average gap setting my efficiency was a consistent 86%. With my new setup in an apartment my efficiency lowered, now have a Monster Mill 2 Pro, same gap setting but my efficiency has gone to 77%-83% mainly due to having less sparge water to use as my boil off in the Robobrew v3 is one gallon per hour less than what I used to boil off. Anyhoo, the point I want to add is when doing my new setup I went with a half inch ball valve on my cooler whereas I used to have the 3/8" valve. Denny recommends opening the valve all the way for maximum flow to set the grain bed quickly. I never did that before but this time went by that advice and personally I don't agree with it at all. I'm finding, at least with my 1/2" valve, that the runoff is too fast and compacts the grain bed in a negative way. As a result I'm seeing some wort still sitting in puddles after I've runoff. That means that wort isn't getting through the grain bed. I'm brewing tomorrow and will go back to slowing the flow like I used to and report back if that stops this from happening.


Rev.
Rev, that's great info!

I never boiled on a burner outdoors since it rains in Seattle all the time. I might look for a big umbrella solution. I also read about craking the valve open for setting the grain bed and have been doing it but never tried a slow runoff during batch sparge. I might try fast runoff during the vorlauf and continue with slow during the sparge and compare the numbers. I will try it and report here after my next brew.
 
Hi Doug,
My strike water was 5 gallons around 164F. I think I used a bit more than 3.5 gallons for batch sparging, that's why ended up with 7.2 gallons in the kettle. I always mash with 1.75 qt/lb to get a bit more efficiency.
5 gal (20 qts) of strike water with 10.5 lbs of grain is 1.9 qt/lb. If this is what you actually used, your first runnings max SG is limited to about 1.066 - 1.067, whereas at 1.75 qt/lb the max SG is about 1.071 - 1.072. So, with your 1.070 first runnings SG, your mash thickness was more likely 1.75 qt/lb, or 10.5 * 1.75 / 4 = 4.6 gal of strike water. I've tried to use the volume, weight and SG numbers you provided in my mash and sparge simulator, but cannot come up with any self consistent results. This usually indicates that there are one or more measurement errors in the input values. Getting accurate efficiency measurements is dependent on having accurate weight, volume, and SG measurements.

Brew on :mug:
 
If I may add one thing about batch sparging in particular. When I used to mash indoors and boil on a Blichmann burner outdoors and had a Monster Mill 2 with a tighter than average gap setting my efficiency was a consistent 86%. With my new setup in an apartment my efficiency lowered, now have a Monster Mill 2 Pro, same gap setting but my efficiency has gone to 77%-83% mainly due to having less sparge water to use as my boil off in the Robobrew v3 is one gallon per hour less than what I used to boil off. Anyhoo, the point I want to add is when doing my new setup I went with a half inch ball valve on my cooler whereas I used to have the 3/8" valve. Denny recommends opening the valve all the way for maximum flow to set the grain bed quickly. I never did that before but this time went by that advice and personally I don't agree with it at all. I'm finding, at least with my 1/2" valve, that the runoff is too fast and compacts the grain bed in a negative way. As a result I'm seeing some wort still sitting in puddles after I've runoff. That means that wort isn't getting through the grain bed. I'm brewing tomorrow and will go back to slowing the flow like I used to and report back if that stops this from happening.


Rev.
A lower boil off means lower pre-boil volume for the same post-boil volume. A lower pre-boil volume for the same grain weight results in a lower lauter efficiency. The metric the characterizes this is the grain weight to pre-boil volume ratio (note this is not the same as mash thickness, or its inverse.) The higher the ratio, the lower the lauter efficiency, all else being equal. The following chart shows this effect. A typical MLT has a grain absorption rate of about 0.12 gal/lb, so the solid lines apply.

Efficiency vs Grain to Pre-Boil Ratio for Various Sparge Counts.png


Let's look at a couple of cases. Both are 11 lb of grain, and 5.5 gal post-boil volume. The first case we assume 2 gal/hr boil off, which implies a 7.5 gal pre-boil volume. In this case the weight to volume ratio is 11 / 7.5 = 1.47 with a single batch sparge lauter efficiency of about 88.5%. The second case we assume 1 gal less boil off than the first case, for a pre-boil volume of 6.5 gal. Here the weight to volume ratio is 11 / 6.5 = 1.69 with a single batch sparge lauter efficiency of about 86%. Mash efficiency equals conversion efficiency time lauter efficiency, so in the case of 100% conversion efficiency, mash efficiency = lauter efficiency. If conversion efficiency is less than 100% then mash efficiency is less than lauter efficiency.

I think Denny's advice on run off rate should be modified to "run off as fast as your equipment will let you, without excessive grain bed compaction." It may be with Denny's equipment, he could not hit a run off rate high enough to over compact the grain bed. I think a good way to determine max run off rate for your equipment, crush, etc. is to calculate the grain absorption ratio, which is given by:

Absorption Ratio = ((Strike Water Vol - MLT Undrainable Vol) - First Runnings Vol) / Grain Wt
The MLT undrainable volume is the volume of liquid left in the MLT after draining water from the MLT with no grain in the MLT. Ideally this volume is zero, as the larger this volume, the lower your lauter efficiency. A typical MLT grain absorption ratio is about 0.12 gal/lb. As long as your ratio doesn't increase from that, you are not draining too fast. If that ratio goes above 0.12 gal/lb, then your MLT is no longer draining freely and completely, so draining too fast.

Brew on :mug:
 
5 gal (20 qts) of strike water with 10.5 lbs of grain is 1.9 qt/lb. If this is what you actually used, your first runnings max SG is limited to about 1.066 - 1.067, whereas at 1.75 qt/lb the max SG is about 1.071 - 1.072. So, with your 1.070 first runnings SG, your mash thickness was more likely 1.75 qt/lb, or 10.5 * 1.75 / 4 = 4.6 gal of strike water. I've tried to use the volume, weight and SG numbers you provided in my mash and sparge simulator, but cannot come up with any self consistent results. This usually indicates that there are one or more measurement errors in the input values. Getting accurate efficiency measurements is dependent on having accurate weight, volume, and SG measurements.

Brew on :mug:
To be exact, I brewed lake walk pale ale and there was also 0.5 lb flaked wheat, which makes the total grain bill 11lb. Beersmith said, strike water should be 19.76qt but I rounded up to 5 gal, it comes close to 1.80qt/lb.
 
Back
Top