Batch Sparge Efficiency Stuck Around 65%...HELP

Hey Everyone!

I'm going on my 10th all grain batch or so and I can't seem to hit efficiency levels higher than 65% to 66%. I've adjusted multiple things over the batches and none have seemed to make a difference. Here's what I'm doing:

• 3-tier brew system all gravity fed with a 10 gallon orange cylindrical cooler with stainless braid manifold for mash tun.
• Use Beersmith to calculate measurements - I sparge using batches that fill 75% of mash tun volume, sparge using equal size batches and drain mash tun before starting batch sparge
• I use the pre-detremined batch sparge mash profiles in Beersmith so I'm usually mashing between 150 and 156 degrees for an hour
• Sparge water temp of 175 degrees
• Grains pre-milled from Austin Homebrew Supply

My preboil and post boil gravities are constantly low and I always adjust the readings for temperature. Any ideas? I've been adding a couple of pounds of base grain for each batch to make up for it, but I'd rather pinpoint the root cause and fix it instead of just throwing a bunch of extra grain into the mix.

Thanks!
Dave

you may want to check out the forum stickies in this section to see if anything there helps you out. also, have a look at this thread in which i've asked similar questions but with a little more detail. already got several helpful answers to try in fine tuning my process for next time.

if none of that is useful i'd post some more specifics about your process. what you have here is good base info but probably not enough to help find the missing 10% or whatever that you're hoping to make up.

How are you measuring your efficiency? You have to account for all liquid left in the kettle and absorbed by the hops to get a proper mash efficiency number.

Or don't go through the hassle and know you are getting 65-66% consistently by the way you measure it and design from there.

Are you sure you're getting complee conversion of your grains?

Sparge water temp of 175 degrees
Grains pre-milled from Austin Homebrew Supply

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These are your two problems.

A. If you are doing a double batch sparge, your first batch sparge should be 190-205* depending on the volume, and the amount of grain to bring the grain bed up to 170*, and the second should be 170-175* to keep the grain bed at 170*.

If you are doing a single batch sparge, your sparge water should be about 180-185*. Again, to bring the grain bed up to 170*. I found when I sparge too cold, my efficiency definitely suffers.

B. The most i've been able to eek out of the Austin Homebrew crush is about 72% while batch sparging. It's not nearly as bad as the crush I get from my LHBS, but it's not what I would call a great crush. They are definitely erring on the side of conservative.

Next time you order from Austin, put in the notes that you would like a very tight crush on your grain. They are very nice people, and will oblige. Just note that you are are increasing your risk for a stuck sparge with a finer crush. If you get worried, you can always throw in a handful of rice hulls

If you are doing a double batch sparge, your first batch sparge should be 190-205*

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I use the same MLT and I only need 182* to get up to 168-169* on the first batch sparge. Although I fill it and add as much water to that first sparge as I can.

After vourlaf I just add the rest of my sparge water at 170* as it drains.

I think it is more of an issue of getting an accurate percentage. If you are consistent with it, why worry?

For a 10 gallon batch 75% eff vs 66% is about 3 pounds of base malt.

scottland said:

These are your two problems.

A. If you are doing a double batch sparge, your first batch sparge should be 190-205* depending on the volume, and the amount of grain to bring the grain bed up to 170*

B. If you are doing a single batch sparge, your sparge water should be about 180-185*. Again, to bring the grain bed up to 170*.

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I'm having a similar problem as the OP, but here is something I did not understand in your quoted answer above.

How 190-205F (A) and 180-185F (B), two very different temperatures, are both supposed to bring the grain bed to 170F like you said???

BendBrewer said:

I think it is more of an issue of getting an accurate percentage. If you are consistent with it, why worry?

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Have to second this. People sometimes (IMO) tend to get too worried about efficiency, when, honestly, it doesn't really matter. Do you like your beer? Than you're kicking ass.

I've gotten to the point where I can predict my efficiency pretty closely depending on where I get my grains. Grains from one LHBS near me usually gets me about 72%. Grains from another, and I usually get 65%. Or I order from BMW, where I get about 75%. I just make sure that I calculate my recipe based on where I'm getting my grains and I'm fine.

Consistent 65% seems totally fine to me. :rockin:

How 190-205F (A) and 180-185F (B), two very different temperatures, are both supposed to bring the grain bed to 170F like you said???

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Initial Grain Bed Temp. When you add first sparge, your grain bed was just at 150ish give or take.

Grain bed during/after sparge is 166-170.

Starting out at different temps.

BendBrewer said:

Initial Grain Bed Temp. When you add first sparge, your grain bed was just at 150ish give or take.

Grain bed during/after sparge is 166-170.

Starting out at different temps.

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Thanks, that makes sense.

Palefire said:

Or I order from BMW, where I get about 75%.

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And, what store is BMW, besides being a nice car?

Yeah I did my first 'double' sparge 2 weeks ago and had it all written out:

6 Gallons 169.5* Mash to hit 153*
6 Gallons 180* Sparge to hit 168*
3 Gallons 180* Add to Sparge as I drain to maintain 168*

Luckily I looked at that long enough to realize that wouldn't work and changed the temp of the last 3 gallons accordingly before adding it.

scottland said:

These are your two problems.

A. If you are doing a double batch sparge, your first batch sparge should be 190-205* depending on the volume, and the amount of grain to bring the grain bed up to 170*, and the second should be 170-175* to keep the grain bed at 170*.

If you are doing a single batch sparge, your sparge water should be about 180-185*. Again, to bring the grain bed up to 170*. I found when I sparge too cold, my efficiency definitely suffers.

B. The most i've been able to eek out of the Austin Homebrew crush is about 72% while batch sparging. It's not nearly as bad as the crush I get from my LHBS, but it's not what I would call a great crush. They are definitely erring on the side of conservative.

Next time you order from Austin, put in the notes that you would like a very tight crush on your grain. They are very nice people, and will oblige. Just note that you are are increasing your risk for a stuck sparge with a finer crush. If you get worried, you can always throw in a handful of rice hulls

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That's helpful to get this sort of feedback about AHS's crush. I may ask them for the tight crush next time to see how that affects things.

However I don't know that missing the intended sparge temperature is a guaranteed reason for efficiency issues. Kaiser did some cold sparge tests where the water was left at room temp and his tests showed no change in efficiency. Lots of factors were pointed out in that thread surrounding why a hot sparge improves people's efficiency in some cases. Check it out: https://www.homebrewtalk.com/f36/cold-water-sparge-110856/

I was also hitting 65% for a long time until I started to adjust my mash pH and waiting longer for conversion.

Using braukaiser's Efficiency analysis spreadsheet helped me discover I wasn't waiting long enough for full conversion.

How I've been calculating my efficiency:I've been using kindof a roundabout way of calculating efficiency. I just take my wort samples at various points in the brew process and compare it to what brewsmith says the gravity should be at certain efficiency levels (for example, at preboil, after sparging, I get my hydroeter sample from the brew pot after I mix it up to combine all runnings and after I check the preboil gravity, I change the efficiency percentage for the recipe in Brewsmith until the estimated gravity readings that it kicks out in the recipe meet mine).
It always ends up right around 65%

Mash / Sparge Schedule:So here's the mash sparge schedule I did for my last batch. This is similar to what I've done for most batches with 65% efficiency. It sounds like I need to increase the temp of the sparge water, correct? Anyone have feedback on whether or not it is better to drain the mash tun before sparging?

-Mash in 4.88 gallons of water at 168.7 degrees
-Hold mash at 154 degrees for 60 minutes
-Drain Mash Tun
-Sparge Round 1 - add 2.86 gallons of 175 degree water
-Sparge Round 2 - add 2.86 gallons of 175 degree water

For each sparge, I add the water, mix it into the grains well with my mash paddle and let sit for 10 minutes before draining.

Any feedback is welcome. Thanks for all of your comments so far!

I drain the MLT before adding sparge water. Then I stir it very well. Let it sit for 10-12 minutes and drain/vorlauf/drain. As it drains I add the second sparge slowly while the sparge water is still above the grain bed. It's just a rinse at that point.

How do you measure your volume when calculating?

And with those volumes, you could just do 1 sparge with maybe a little bit left over to add while you are draining.

I let Beersmith do the volume calculations and I have a site glass on my HLT that is marked at every .5 gallon which I watch when I open / close the ball valve to move the right amound of mash in / sparge water.

Have you measured your loss from the evaporation, absorption and just left behind in the kettle? These would all effect your %.

I leave my Batch Size at 10 gallons as that is what I get to keg. (About 10.5 gallons to fermenter)

When I do this, I end up with about 67% eff. every time.

In actuality, I end up with more like 11.25 gallons of total wort post boil which is really 73%.

I wouldn't worry about what your % is as long as it is respectable as there are many factors whose quantities aren't known precisely. The key is you are consistent and can trust your numbers now without changing anything.

Mash / Sparge Schedule:So here's the mash sparge schedule I did for my last batch. This is similar to what I've done for most batches with 65% efficiency. It sounds like I need to increase the temp of the sparge water, correct? Anyone have feedback on whether or not it is better to drain the mash tun before sparging?

-Mash in 4.88 gallons of water at 168.7 degrees
-Hold mash at 154 degrees for 60 minutes
-Drain Mash Tun
-Sparge Round 1 - add 2.86 gallons of 175 degree water
-Sparge Round 2 - add 2.86 gallons of 175 degree water

For each sparge, I add the water, mix it into the grains well with my mash paddle and let sit for 10 minutes before draining.

Click to expand...

Yes, drain every drop out of you mash tun. Tilt it up on its edge to get all of the fluid out of it.

What is your batch size?

How much grain are you putting into your mash tun?

What is the pH of your mash after 10 minutes?

If you are doing a 10 gallon batch you need to use more sparge water. It looks like you are putting 10.6 gallons total (mash + sparge). I would think that this would put you in the 8-9 gallon range going into the fermenter.

Without more data it is very hard to diagnose where your efficiency loss is coming from. It could be your crush, it could be your water, it could be a bum thermometer or hydrometer. It could be a lot of things.

Also, the way that most of us understand efficiency is as follows:

eff%=(amount of sugar you extracted)/(total amount of sugar available)*100%

or:

eff%=(gravity*volume)/(extract potential*weight of grain)*100%

I don't know how you got your efficiency. But an example goes as follows:

Lets say I made a 5 gallon batch with 10 lbs of 2-row malt. The total amount of sugar available for extraction is 370 gravity points (37 points per pound*10 pounds). If you get an OG of 1.074, thats 100% efficiency (74*5/370=1*100%=100%). 85% efficiency gives you 1.063. etc.