Efficiency is constantly crazy low.. why?!

Hey fellas. I need your help to identify the reason(s) my efficiency is consistently so darn low. I brewed about 15 batches in the past year and they all were below 70% efficiency, even for low grain bill recipes. I brewed a couple of higher expected OG beers recently and got about 55-60% efficiency… This is embarrassing! I use BeerSmith for all my calculations and parameters. Can you point out some aspects where I could be making mistakes that are costing me some efficiency points? I would be very grateful!

So here is my routine:
-Condition my grains with 2% water. Let it condition for 15minutes before milling
-Mill grains at Barley Crusher’s factory’s gap (0.039)
-Prepare my Strike water. Depending on recipe, I usually mash at 152F-153F (can take a couple of minutes and addition of cold/hot water to reach my target temperature since I brew in my garage and outside temperature affects ambient temperature) with 1.25-1.5qt/lbs.
-Incorporate grains in MLT by stirring with a grout mixer – let sit for 60minutes.
- Vorlauf (about 1Gallon or until wort is clear)
- Prepare Fly Sparge water. Heat to 170F and start Fly Sparge at an approximate rate of 1qt/minute
- Stop Fly sparge when pre-poil volume is reached (measured with BeerSmith)
- Good boil for 60 (or 90minutes depending on recipe). Add hops, Irish moss and yeast nutrient. Chill with immersion chiller to 30F, whirlpool with grout mixer and let sit for 15minutes.
- Transfer to Fermenter and incorporate rehydrated dry yeast. Take gravity sample and adjust it if wort temperature is not at hydrometer’s calibrated temperature.
- Ferment in my Fermentation chamber at 65F for first 3 days then bump up to 68F until fermentation is over.

My equipment:
-16Gallons Brew Kettle with dip tube and thermometer
-10.7Gallons Mash Tun: Round Cooler with homemade CPVC manifold (used a false bottom – made specifically for my MLT- for 2 batches and I couldn’t get a clean wort and had very poor efficiency so I returned the false bottom to the store and continue using my manifold). I barely loose a degree for an hour long mash.
-3 tiers brewstand with Brew Kettle and HLT sitting on Propane burners

Good to know:
- I am using water from my personal water well. It is very good to drink, no chlorine but is a tiny bit hard.
- I brew in my heated garage so in Canadian winters (like now), it can reach 10F easily. Temperature in the garage is usually kept around 50F.
- I’ve been using a refractometer for a while, but went back to a hydrometer recently as I feared the refractometer wasn’t giving me the exact gravity (I calibrated it and used the formula for fermented wort)

Narrow your mill gap to a carefully measured 0.035" (for starters) and give that a try for a few batches to see if your efficiency goes up. Then if you see benefit, try 0.032" next.

Most credit cards are about 0.030", but I have a few that are 0.032". It seems that the newer ones with the embedded chip are just a tad thicker, and these are the most likely to gauge 0.032".

If you start experiencing stuck sparges you have gone too far.

I agree about the mill gap. Also, you might try batch sparging. I never had much success with fly sparging (this is on me and not really the technique). I found batch sparging to be easier to hit my efficiency consistently and takes less time.

My $0.02:

1. Tighten the gap on your mill. Most efficiency problems are due to grain crush

2. Check SG using both refractometer and hydrometer until you can trust your refractometer. Ensure your numbers are real.

3. When you say your efficiency, do you mean mash efficiency or brewhouse efficiency? If the latter, how much trub do you leave behind? If the former, is the wort stirred VERY week before measuring the sample?

4. Do you make good beer? If so, consider this a VERY minor issue.

I just received my feeler gauge so I'll be able to try that for sure.

But even at 0.039, I feel like my efficiency should be acceptable.. no?

Also, because I milled at 0.040-41 for a recent batch and got stuck sparge (probably because it was an Oatmeal Stout and I used oat and flaked barley). Anyway, I'll try narrowing my gap a bit, but I feel a 55-60% efficiency is pretty low, even for a 0.039 gap.

For example, I brewed a WeeHeavy (high OG) with expected OG (at 70# eff.) of 1.089. I ended up with 1.079

I thought about it, but always heard fly sparge gave you better eff. + my system is more configured for fly sparge.

I guess if I can't bump up the efficiency, I'll have to try that!

oujens said:

I agree about the mill gap. Also, you might try batch sparging. I never had much success with fly sparging (this is on me and not really the technique). I found batch sparging to be easier to hit my efficiency consistently and takes less time.

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In my experience, there was no difference between batch and fly. Most people find fly to be slightly more efficient.

max384 said:

My $0.02:

3. When you say your efficiency, do you mean mash efficiency or brewhouse efficiency? If the latter, how much trub do you leave behind? If the former, is the wort stirred VERY week before measuring the sample?

4. Do you make good beer? If so, consider this a VERY minor issue.

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I guess I speak about brewhouse efficiency, considering I take gravity right before incorporating the yeast in the fermenter?

How much trub do I leave behind.... in the kettle? I guess a good amount of trub is left in the kettle, as I whirlpool before transfering ... BUT I have to admit there is an abnormally thick (approx. 2.5in) trub cake in the bottom of my carboy right now (not much hops - only added 2oz to boil, probably yeast and mostly stuff from the unclear wort after failed vorlauf with my awful false bottom). Does trubs affect gravity readings?

I would guess it's related to your water. If you aren't adjusting your mash pH, start there. Second to that, consider calcium additions.

From Palmer's Water (page 147) : "Calcium is the friend of all brewers who brew with alkaline water. The reaction with malt phosphates is one of the primary mechanisms for the mash pH drop. It is remarkably flavorless. It protects, stabilizes, and promotes enzyme activity in the mash. It aids in protein coagulation, trub formation, oxalate precipitation, yeast metabolism, and yeast flocculation. The calcium levels in the water need to be high enough to carry sufficient levels through the boil and fermentation. A range of 50-200 ppm in the water for the mash is recommended."

I'll verify my pH (I ordered test strips but never received them, thanks eBay!) but I am under the impression that my water, being hard, already contains a good amount of calcium..? I'll verify that it is between 50 and 200ppm!

Going to beat a dead horse a little but there are a few main methods of improving efficiency:

Tighter crush
Longer mash
Stir during mash
Slower fly sparge (it should take 30-40 minutes) or batch sparge

Tighten your crush and batch sparge with a 15-30 minute soak in the 170F water. That will be the easiest way to significantly boost your efficiency.

jojacques said:

I'll verify my pH (I ordered test strips but never received them, thanks eBay!) but I am under the impression that my water, being hard, already contains a good amount of calcium..? I'll verify that it is between 50 and 200ppm!

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I recently started to dabble with pH to increase efficiency. My first step was getting the water tested. Only to find out that my water is terrible! Should not be used for brewing!

Just the other day I ordered a 20 gallon drum and an RO system. Altogether about $300.

It just seems to me that pH is your issue because the malts usually associated with IPAs don't have that much acid to bring down the pH. Of course I do full volume batches and no sparge so my pH is generally going to need to get brought down anyway.

With harder water, acidifying your sparge water as well can help. I worked for a commercial brewery with hard well water. We used phosphoric acid to lower mash pH and also acidified our sparge water. We knew our calcium content to be high. The beers we brewed that were primarily base malt would hit 90%+ efficiency. Obviously commercial systems are designed to be a little bit more efficient, but these types of problems are typically water related. As for the pH strips, it can be very difficult to distinguish small differences on the ones I have used. If it's at all possible to buy a decent portable pH meter, it's worth the splurge. Happy brewing friends, Cheers!

Tighter crush - I'll try a bit tighter, around 0.035 see if I get any stuck mash (cross fingers)
Longer mash - Longer than 60minutes?
Stir during mash - I stir once during Mashing, after 30minutes. I don't always do it though!
Slower fly sparge (it should take 30-40 minutes) or batch sparge - I would say I am close to that, maybe a bit too quick. I'll slow down my sparge a bit!

"Batch sparge with a 15-30 minute soak in the 170F water" - Do you mean I complte fly sparge and end the process with a 15-30minute soak batch sparge?

TheMadKing said:

Going to beat a dead horse a little but there are a few main methods of improving efficiency:

Tighter crush
Longer mash
Stir during mash
Slower fly sparge (it should take 30-40 minutes) or batch sparge

Tighten your crush and batch sparge with a 15-30 minute soak in the 170F water. That will be the easiest way to significantly boost your efficiency.

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Perhaps the 15-30 minute rest at 170 degrees suggestion is actually referring to doing a mash-out stage and rest before the initiation of the sparge?

jojacques said:

Longer mash - Longer than 60minutes?

Stir during mash - I stir once during Mashing, after 30minutes. I don't always do it though!


"Batch sparge with a 15-30 minute soak in the 170F water" - Do you mean I complte fly sparge and end the process with a 15-30minute soak batch sparge?

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I do 90 minute mashes on bigger beers, just to boost the efficiency a little. I've even heard of people mashing overnight, though it's not common.

I stir every 15-20 minutes during the mash just to make sure things stay mixed up

EDITED: No, sorry, I mean that IF you batch sparge, you would essentially just drain off your first runnings, then pour in a portion of your sparge water, let it sit for 15-30 minutes, then drain off the sparge water, and repeat until you hit your pre-boil volume or low wort gravity of 1.010.

I'll keep that in mind if I end up trying the batch sparge method.

I guess a longer Mash could have been used for my Wee Heavy (Which will probably be closer to a Strong Irish Ale after the low OG)

bulldogbrewhaus said:

With harder water, acidifying your sparge water as well can help. I worked for a commercial brewery with hard well water. We used phosphoric acid to lower mash pH and also acidified our sparge water. We knew our calcium content to be high. The beers we brewed that were primarily base malt would hit 90%+ efficiency. Obviously commercial systems are designed to be a little bit more efficient, but these types of problems are typically water related. As for the pH strips, it can be very difficult to distinguish small differences on the ones I have used. If it's at all possible to buy a decent portable pH meter, it's worth the splurge. Happy brewing friends, Cheers!

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Thanks for the Info. I'll probably end up getting my water tested by the city (I got it tested two years ago but lost the report). I'll post my new results once I get em!

Also, make sure you have sufficient base malts with high diastatic enzyme power to convert all of the starch to sugar. Insufficient diastatic enzymes is a sure way to get lousy efficiency. Some UK and European base malts have noticeably lower enzymes than do domestic base malts.

you could consider stirring in a half tsp of amalyse enzyme to your mashes.

http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency

This should help

Silver_Is_Money said:

Also, make sure you have sufficient base malts with high diastatic enzyme power to convert all of the starch to sugar. Insufficient diastatic enzymes is a sure way to get lousy efficiency. Some UK and European base malts have noticeably lower enzymes than do domestic base malts.

you could consider stirring in a half tsp of amalyse enzyme to your mashes.

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This is a good point and a variable not yet discussed on this thread.

I usually use at least 80% base malt (right now, using OiO Canadian Base Malt) in my recipes. But good to know, I wasn't aware!

Been said several times, but I would give batch sparging a try. Re-brew a recipe that gave you low efficiency and keep EVERYTHING else the same. Drain off first runnings, add sparge water and stir like it owes you money for a couple of minutes (credit to @Yooper for that expression). Vorlouf and drain. (Calculate so that first runnings and sparge volume are equal or close to it.) Finish brew and check SG. Calculate your efficiency and see how you did. This will tell you if it is your sparge technique or not. But it is important to only change ONE thing or else you won't know what made the change.

I suggest this first because fly sparging can easily have channeling which will decrease efficiency, and because it is one of the easiest changes to make.

Good luck and report back!

Ditch the fly sparge. A batch sparge will save time and probably increase your efficiency. A poor fly sparge will wreck you and it may not be your fault so much as the equipment. Not sure what your manifold looks like but channeling is a concern with a fly sparge. How you're adding the water, how close the manifold is to the wall, how close each rung of your manifold is, etc. these things affect a fly sparge and not a batch sparge.

Batch sparge:
mash as usually
remove wort tip the MLT and get it all out
heat your sparge water to 180 ish and dump it in the MLT
stir and drain
tip the MLT get it all out

A mash out isn't necessary with a batch sparge don't waste your time. Get you your first runnings into the pot and start the heat while you run off the sparge. Very quick process. The reason you mash out with a fly sparge is to stop conversion while you're conducting the possibly very lengthy fly sparge. Just because the starch is converted doesn't mean that there won't be work done on the dextrines produced during your mash. Essentially breaking them down further into fermentables. Essentially, its to "lock in" the characteristics you achieved in the mash.

When I made the change to a batch sparge I was very pleased. A little annoyed about the time I wasted trying to get my fly sparging to work well but whatever. If I ever go bigger than 5 gallons I'll return but until then I'llt ake the easy road. I think you should give it a try. I went from efficiency ranging in the 50s to 82% repeatably which is nice to know when building recipes.

That's my 2 cents. Good luck.

jojacques said:

I guess I speak about brewhouse efficiency, considering I take gravity right before incorporating the yeast in the fermenter?

How much trub do I leave behind.... in the kettle? I guess a good amount of trub is left in the kettle, as I whirlpool before transfering ... BUT I have to admit there is an abnormally thick (approx. 2.5in) trub cake in the bottom of my carboy right now (not much hops - only added 2oz to boil, probably yeast and mostly stuff from the unclear wort after failed vorlauf with my awful false bottom). Does trubs affect gravity readings?

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If you leave, for example, a gallon of trub in the kettle, that's a lot of gravity points that are then left unaccounted for. This is only true, however, if you only consider the volume in the fermenter when determining efficiency. You could have great mash efficiency, but if your volumes are off, it will affect your brewhouse efficiency.

If you're hitting your OG, but having low efficiency, that may be your problem. If your OG is also consistently low, this is unlikely to be the issue. But, of course, this could be a minor part that is contributing to your overall brewhouse efficiency.

I would check your pre- and post-boil gravities to determine your mash and brewhouse efficiencies, respectively. This will at least let you know where you stand.

Its a good point.
Just to make sure my setup allows for batch sparge: Is it ok if I cannot dump all the sparge water real fast to the mash (so the water stirs the grains)?

I am using a 3 tiers brewstand, so I open my HLT valve and can drop 5 gallons of water in my mash tun in about 1 minute. I would need to stir the mash myself... is this a big deal?

In the end, though, if you have to adjust your recipes to account for low efficiencies, and you still make good beer, I wouldn't worry about it. Nobody's going to drink your beer and tell you it tastes like you have low efficiency.

max384 said:

In the end, though, if you have to adjust your recipes to account for low efficiencies, and you still make good beer, I wouldn't worry about it. Nobody's going you drink your beer and tell you it tastes like you have low efficiency.

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Ahah I agree with that, and beer is coming out amazing. But still, I would love to spend less on grains and/or get higher alc %

max384 said:

Nobody's going you drink your beer and tell you it tastes like you have low efficiency.

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Sig material, that. Kudos!

The 90 minute mash has always intrigued me - I start checking my mashes 20 minutes in - and sometimes they're completely converted in 20 minutes. Most of the time they're completed in 30 to 45 minutes.

I'm with the majority here - tighten up your mill.

There are many different efficiencies defined for the brewing process:
Conversion Efficiency: The actual amount of sugar created in the mash divided by the potential amount of sugar in the grain bill.
Lauter Efficiency: The amount of sugar that makes it into your boil kettle divided by the amount of sugar that was created in the mash.
Mash Efficiency: a.k.a. Pre-Boil Efficiency. The amount of sugar that makes it into your boil kettle divided by the potential amount of sugar in the grain bill. Mash Efficiency equals Conversion Efficiency times Lauter Efficiency.
Transfer Efficiency: The amount of sugar in your fermenter divided by the amount of sugar in your boil kettle. Also equal to the fermenter volume divided by the post-boil volume.
Brewhouse Efficiency: The amount of sugar that makes it into your fermenter divided by the potential amount of sugar in the grain bill. Brewhouse Efficiency equals Mash Efficiency times Transfer Efficiency. Also equals Conversion Efficiency times Lauter Efficiency times Transfer Efficiency.
All of the above definitions are for fractional efficiency. You can convert any fractional efficiency to percentage by multiplying by 100%. However, if you are multiplying efficiencies together, you need to do that with fractional efficiencies.

The first thing to do is determine if your low efficiency is due to low conversion efficiency, poor lauter efficiency, or poor transfer efficiency (if it's your brewhouse efficiency that you think is low.) They are caused by different mechanisms, and require different actions to improve them.

Conversion efficiency can easily be measured just by measuring the SG of the wort in the mash. Turns out the maximum SG of the wort in the mash (at 100% conversion) is almost totally dependent on the mash thickness. Kai Troester provides a table of mash thickness vs. max SG here, and describes how to use that, and your measured SG, to determine conversion efficiency. If your conversion efficiency is less than about 95%, you should try to improve it. Things to do to improve your conversion efficiency:

• Crush finer.
• Mash longer.
• Stir the mash more.
• Make water adjustments to keep mash pH in the range of 5.2 to 5.7.
• Add more diastatic power to the mash.

Mash efficiency can be obtained using on-line calculators using either post-boil volume and post-boil SG measurements, or pre-boil volume and pre-boil SG. It's easier to get accurate SG measurements post-boil, since pre-boil wort can have significant stratification if you sparge, and it's difficult to mix well enough to completely eliminate the stratification. However, you cannot use the post-boil measurements if you added any sugar during the boil. Once you have your mash efficiency, divide by the conversion efficiency to determine your lauter efficiency. Then compare your lauter efficiency to the chart below. A traditional MLT should have a grain absorption rate of about 0.12 gal/lb, so use those curves in your comparison (unless you are BIAB'ing and squeezing the bag.) If you are fly sparging, and your lauter efficiency is less than that for batch sparging, then you are wasting your time by fly sparging. Factors that negatively affect batch sparge lauter efficiency:

• Inadequate stirring. Need to stir well before vorlauf and drain for each run-off.
• Excessive undrainable volume in the MLT. Undrainable volume in the MLT should be minimized, and ideally less than a pint (0.125 gal.)

Factors that negatively affect fly sparge lauter efficiency:

• Channeling. This can be caused by poor false bottom or manifold design, or sparging too fast.
• Sparging too fast, thus not allowing enough time for diffusion to move sugar into the sparge water.

If your conversion and lauter efficiencies are both acceptable, but your brewhouse efficiency is low, then look at your equipment to find and eliminate places that retain wort, and thus keep it from ending up in the fermenter.

Brew on

max384 said:

Nobody's going you drink your beer and tell you it tastes like you have low efficiency.

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Yup totally stealing that.. hilarious!

Hahaha. Thanks guys.... I only wish I hadn't made the autocorrect error!

max384 said:

Hahaha. Thanks guys.... I only wish I hadn't made the autocorrect error!

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Nothing a little quotoshop can't fix [emoji23]

doug293cz said:

There are many different efficiencies defined for the brewing process:
Brew on

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Amazing info, thanks a bunch!!

jojacques said:

Its a good point.
Just to make sure my setup allows for batch sparge: Is it ok if I cannot dump all the sparge water real fast to the mash (so the water stirs the grains)?

I am using a 3 tiers brewstand, so I open my HLT valve and can drop 5 gallons of water in my mash tun in about 1 minute. I would need to stir the mash myself... is this a big deal?

Click to expand...

Just drain your sparge water in, give it a good stir, vorlauf, drain into the kettle.

For mill gap, when I last batch sparged (I now do full volume BIAB) my mill was set at .033 with no stuck sparges. I imagine .035 would get you some improvement with no stuck sparge. Be sure that if using any wheat malt you mill those separately on a tighter setting and add rice hulls to your mash.

Read my blog post on troubleshooting efficiency.

Take more measurements to separate lauter efficiency and conversion efficiency. (details in blog post). Take a look at my mash calculator for an estimate on sparge efficiency, which basically compares your lauter efficiency to that of an ideal batch sparge. If it's not at least 130%, I would recommend not fly sparging.

I have been dealing with very low conversion efficiency as well. I finally called public works, got a water report, and spoke to the guy who runs the treatment plant! Apparently we have total dissolved solids around 212-235 but almost 0 calcium and about 110 of that TDS is dissolved silicate. I know the calcium is a huge factor, but I suspect that silicate has to be having an effect as well. Does anyone know what effect if any silicate has and how to address it?
And what would you use to add calcium and in what amounts?

TANSTAAFB said:

I have been dealing with very low conversion efficiency as well. I finally called public works, got a water report, and spoke to the guy who runs the treatment plant! Apparently we have total dissolved solids around 212-235 but almost 0 calcium and about 110 of that TDS is dissolved silicate. I know the calcium is a huge factor, but I suspect that silicate has to be having an effect as well. Does anyone know what effect if any silicate has and how to address it?
And what would you use to add calcium and in what amounts?

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That sounds like terrible brewing water. Just adding calcium won't get rid of the other crap in it. What else is in there that makes up the other 110 - 120 of TDS? I wouldn't be surprised if it had other bad stuff, like iron for example. If I had water like that, I would just go with straight RO water, and build up the ions to a reasonable profile. You can buy RO water at most grocery stores, or install your own RO water generation system at home.

Brew on

My beer tastes great but I'm sure it would taste even better with good water! I used to brew with really hard but really good Texas well water. Damn... I was hoping to avoid screwing with water and building up from scratch...