Help me with Efficiency

[BigJoeBrew]

Just brewed an Dry Irish Stout yesterday and ran into a good problem, but was not ready to deal with it. So, I want to try to learn from this experience.

Dry Irish Stout
8.25lbs. Maris Otter
2.25lbs. Flaked Barley
1.25lbs. Roasted Barley

Predicted OG 1.058 for 5.5 gallons @ 75% efficiency

Actual OG was 1.068 for 5.75 gallons

Questions
1) I calculated efficiency as 91.6%. Which efficiency is this (Brewhouse, Mash, or other)?

2) If I would have topped off to bring OG down to where it needed to be my fermenter would have been way to full. What do you do with the extra?

3. I am using a corona style mill that isn't precise at all. Should I start planning on 80-85% efficiency or still 75% as I have been?

 

[shaky6]

Hey that seems like a good problem to have! I use a corona mill like you do and I'm way down in the 65% efficiency range, but I also account for other brewhouse equipment not being up to snuff. A one time shot isn't going to set your benchmark. I'd try and get 3 consistent batches before I started to worry.

 

[McKnuckle]

The 75% and 91% values would be mash efficiency. But one cannot exceed 100% conversion efficiency; so in order to have such high mash efficiency, your grain absorption would need to be in the 0.05 gal/lb range, which is possible only for very aggressive BIAB bag-squeezers who also leverage an extended drain. I wouldn't think it possible with a traditional mash tun where the grain is just sitting there.

 

[BigJoeBrew]

I think my crush was pretty fine. Should of taken a pic. I squeezed the bee-jesus out of the bag and then did a dunk/batch sparge/ with a good stir, let rest 5 min then drained and squeezed again.

Here were my refract readings

Started with 5 gallons
First runnings - Yield 4 gal @1.081
Second runnings - Yield 2.75 gal @ 1.036
Pre Boil - 6.75 gal @ 1.062


I guess I got lucky this go round with crushing finer.

 

[Cavpilot2000]

Spend less time on the internet.
Your efficiency with everything else will improve significantly.

 

[TheMadKing]

Just add more water until you hit your OG. Being too efficient is never a bad thing.

I'm also slightly suspicious of an efficiency that high. How are you measuring your volumes and specific gravities?

 

[Morrey]

Yep, your OG was well over expected driving your brew house efficiency into the 91% range. As TheMadKing expressed, I'd double and triple check your numbers to make sure all was accurate. I use a refractometer for OG myself, but I typically do a floating hydrometer as well to double check.

While this is certainly a job well done pat on the back, you will want to find some sort of consistency in your efficiencies. With a 91% in the books, do at least a few more brews before you plug that number in and start reducing your recipe's grain bill. It is far better to be a consistent 78% brewer (arbitrary example) than to hit a high one brew day and a low the next.

 

[Cavpilot2000]

Are you taking your gravity readings at approx. 68 degrees F?
Readings will be dramatically altered if your wort is hot when you take the reading (it will read much lower than actual).
If you are taking readings from hot wort (say, coming out of your mash tun into your kettle), you need to use a temperature calibration tool.
Brewers friend has one online that's free. Just plug in your numbers and temps and it corrects for you.

 

[Bowtiebrewery]

Certainly think about getting a refractometer. They are super helpful. Also they make ones that only tell brix, and others that have the conversion for SG on them. I would recommend the latter.

Do you ever have stuck sparges? You might be milling quite fine.

 

[dmtaylor]

With a Corona mill, I believe you actually did in fact get >90% brewhouse efficiency. The Corona mills are known for grinding very fine, which is what it takes for awesome efficiency. I myself used to average >90% brewhouse until I wondered if it was causing a thinness and lack of depth of malt flavor, then I dialed the gap back (on my Barley Crusher mill) to achieve 81% efficiency instead on purpose. But is it possible and likely to get >90% with a Corona? Absolutely! I'm not surprised in the slightest. Yes, with this mill you should plan on higher than average efficiency for every batch. With really big beers like barleywines and imperial stouts, it will fall to the 70s. But for standard gravity beers, it is likely to stay high.

 

[TheMadKing]

With a Corona mill, I believe you actually did in fact get >90% brewhouse efficiency. The Corona mills are known for grinding very fine, which is what it takes for awesome efficiency. I myself used to average >90% brewhouse until I wondered if it was causing a thinness and lack of depth of malt flavor, then I dialed the gap back (on my Barley Crusher mill) to achieve 81% efficiency instead on purpose. But is it possible and likely to get >90% with a Corona? Absolutely! I'm not surprised in the slightest. Yes, with this mill you should plan on higher than average efficiency for every batch. With really big beers like barleywines and imperial stouts, it will fall to the 70s. But for standard gravity beers, it is likely to stay high.

I might be wrong, but I think you are referring to your mash efficiency not your brewhouse efficiency.

Brewhouse efficiency is very unlikely to be that high unless you had a high conversion and lauter efficiency (90%+) AND wasted virtually zero water in your process from beginning to fermentor (including almost no grain absorption or boil-off). Brewhouse takes into account the overall efficiency of your system and it's ability to make your target gravity and target volume with minimal loss of sugars or water. Mash efficiency just describes what percentage of available sugars in your grain ended up in your wort.

If you have a true brewhouse efficiency much higher than 80% I would be very surprised/impressed.

 

[Morrey]

With a Corona mill, I believe you actually did in fact get >90% brewhouse efficiency. The Corona mills are known for grinding very fine, which is what it takes for awesome efficiency. I myself used to average >90% brewhouse until I wondered if it was causing a thinness and lack of depth of malt flavor, then I dialed the gap back (on my Barley Crusher mill) to achieve 81% efficiency instead on purpose. But is it possible and likely to get >90% with a Corona? Absolutely! I'm not surprised in the slightest. Yes, with this mill you should plan on higher than average efficiency for every batch. With really big beers like barleywines and imperial stouts, it will fall to the 70s. But for standard gravity beers, it is likely to stay high.

Dave, let me apologize in advance to the OP for this semi-hijack question on his thread.

However we are discussing efficiency and I personally feel that milling the grains is a big part of the efficiency equation. I use a Kegco 3 roller mill powered by a hand held variable speed 10 amp drill. I always get my wife to pour the grain in the hopper, and we have pretty well gotten our groove down with the speed I run the drill and the flow of the grain into the hopper. I run the drill at a low-medium speed so the grain flow is slow so the rollers keep moving w/o too much grain weight on top bogging them down. About 2" of grain in the hopper works well for my drill speed. With all of this grinding description, I have gotten 81% efficiency (brew house into fermenter) like clockwork for my last 10 or so average SRM beers. In other words, I feel that running a mill with speed and technique consistently is translating into efficiency consistency in the end. Have you or others found this to be true, or is this my imagination? However, something is dialed in to repeat efficiency this often.

 

[pricelessbrewing]

A good crush does one main thing, and one secondary thing for some people.

1) Ensures adequare gelatinization and speeds up conversion rate. If mash ph is managed, and a good dough in is performed, you can all but guarantee >92% CONVERSION efficiency. Crushing finer may speed it up slightly, and may gain you an additional 2-3%, but not likely to be higher. 97% conversion is a pretty hard upper bound.

2) If you're FLY sparging, crushing as fine as possible can have a negative affect as it may cause the grain bed to promote channeling. However the people that crush super fine usually do BIAB, and at most do a batch sparge, very few people do BIAB + fly sparge.

I have a small intuition that a fine crush may impact the way that the grain bed releases wort when squeezing and improve lauter efficiency, but I'm still trying to plan an experiment for that.

 

[dmtaylor]

If you have a true brewhouse efficiency much higher than 80% I would be very surprised/impressed.

I am seriously fairly certain that at one point in time, both my mash and lauter efficiencies were in the 94-96%, which when multiplied took my brewhouse efficiency to the 90-92% average that I was seeing. You are quite correct about not wasting a drop. I typically BIAB, AND always sparged, AND let the bag drip all during the boil, adding any drippings to the boil every few minutes, so that nothing indeed was wasted. By the end there's pretty much nothing left in the spent grains but empty husks -- almost zero pieces of white starch, nothing left to convert. Yep, pretty sure.

 

[dmtaylor]

Dave, let me apologize in advance to the OP for this semi-hijack question on his thread.

However we are discussing efficiency and I personally feel that milling the grains is a big part of the efficiency equation. I use a Kegco 3 roller mill powered by a hand held variable speed 10 amp drill. I always get my wife to pour the grain in the hopper, and we have pretty well gotten our groove down with the speed I run the drill and the flow of the grain into the hopper. I run the drill at a low-medium speed so the grain flow is slow so the rollers keep moving w/o too much grain weight on top bogging them down. About 2" of grain in the hopper works well for my drill speed. With all of this grinding description, I have gotten 81% efficiency (brew house into fermenter) like clockwork for my last 10 or so average SRM beers. In other words, I feel that running a mill with speed and technique consistently is translating into efficiency consistency in the end. Have you or others found this to be true, or is this my imagination? However, something is dialed in to repeat efficiency this often.

Morrey,

I'm trying to figure out exactly what it is you're asking... if you are talking about my statement about how really big beers lower the brewhouse efficiency, I have found this to be true. Even if efficiency is consistent at some number (81% or whatever) for standard grain bills, even if you do exactly the same crush for a really monster grain bill, the spent grains will permanently soak up so much of that sugar that only a commensurately monster sparge volume and mega-long boil for like 2.5-3 hours or more will keep your efficiency consistent. But if you only sparge a couple gallons and keep to the standard 60-90 minute boil, you just cannot get there. When I make a barleywine of say 1.115 original gravity and do this all-malt, no extract, it's possible, but I have to plan for at least enough pre-boil volume from sparging that I can boil for a good 2.5 hours at least. Then it is achievable. Otherwise, efficiency falls to the 60s or 70s, even with an awesome crush. It's just that with say 22 lb of grains for a 5-gallon batch, the spent grains will want to hang onto way more sugar than your typical 11-12 lb mash would, based on volumes alone really.

I hope this is making some sense and answered your question(?).

 

[Morrey]

Morrey,

I'm trying to figure out exactly what it is you're asking... if you are talking about my statement about how really big beers lower the brewhouse efficiency, I have found this to be true. Even if efficiency is consistent at some number (81% or whatever) for standard grain bills, even if you do exactly the same crush for a really monster grain bill, the spent grains will permanently soak up so much of that sugar that only a commensurately monster sparge volume and mega-long boil for like 2.5-3 hours or more will keep your efficiency consistent. But if you only sparge a couple gallons and keep to the standard 60-90 minute boil, you just cannot get there. When I make a barleywine of say 1.115 original gravity and do this all-malt, no extract, it's possible, but I have to plan for at least enough pre-boil volume from sparging that I can boil for a good 2.5 hours at least. Then it is achievable. Otherwise, efficiency falls to the 60s or 70s, even with an awesome crush. It's just that with say 22 lb of grains for a 5-gallon batch, the spent grains will want to hang onto way more sugar than your typical 11-12 lb mash would, based on volumes alone really.

I hope this is making some sense and answered your question(?).

I have a close friend who owns a local micro-brewery and he showed me his grain bill and efficiency % for his high gravity beers. Even with the latest and greatest new brewing equipment available, he simply can't get the efficiencies with big beers as he can with 1.050 beers. Plus he can't show the numbers to offset the cost of boiling 2.5-3 hours to concentrate the wort, so he takes a loss in the efficiency category. He showed me how much this HG beer cost to make, then he asked if I can now see why he charges about double for a pint of HG beer in his tap room. It was obvious why.

I figure as home brewers, we may actually have a bit of advantage over the larger operations at least in this one small regard since we may be able to boil longer at lower costs, but not sure about that. Unless you boil insane lengths to boil off insane sparge volumes, the loss is going to plague us all with big beers.

 

[BigJoeBrew]

Spend less time on the internet.
Your efficiency with everything else will improve significantly.

I am sure that would do us all some good!

Just add more water until you hit your OG. Being too efficient is never a bad thing.

If I would have added anymore water there wouldn't have been enough room in the fermenter. What do others do with the extra wort that doesn't fit?

I'm also slightly suspicious of an efficiency that high. How are you measuring your volumes and specific gravities?

Are you taking your gravity readings at approx. 68 degrees F?
Readings will be dramatically altered if your wort is hot when you take the reading (it will read much lower than actual).
If you are taking readings from hot wort (say, coming out of your mash tun into your kettle), you need to use a temperature calibration tool.
Brewers friend has one online that's free. Just plug in your numbers and temps and it corrects for you.

Certainly think about getting a refractometer. They are super helpful. Also they make ones that only tell brix, and others that have the conversion for SG on them. I would recommend the latter.

Do you ever have stuck sparges? You might be milling quite fine.

I do have a refractometer and I made sure to double check before pitching with my hydrometer. Also, since I do BIAB I did a batch sparge this time around. My grind was definitely finer than I think it has been before.

 

[BigJoeBrew]

LOL! Great info on the HG beers. I will have to keep that in mind if I give one a try.

Morrey,

Do you find that your mill bogs down if you just fill the hopper and hit the drill with it?

Dave, let me apologize in advance to the OP for this semi-hijack question on his thread.

However we are discussing efficiency and I personally feel that milling the grains is a big part of the efficiency equation. I use a Kegco 3 roller mill powered by a hand held variable speed 10 amp drill. I always get my wife to pour the grain in the hopper, and we have pretty well gotten our groove down with the speed I run the drill and the flow of the grain into the hopper. I run the drill at a low-medium speed so the grain flow is slow so the rollers keep moving w/o too much grain weight on top bogging them down. About 2" of grain in the hopper works well for my drill speed. With all of this grinding description, I have gotten 81% efficiency (brew house into fermenter) like clockwork for my last 10 or so average SRM beers. In other words, I feel that running a mill with speed and technique consistently is translating into efficiency consistency in the end. Have you or others found this to be true, or is this my imagination? However, something is dialed in to repeat efficiency this often.

 

[BigJoeBrew]

A good crush does one main thing, and one secondary thing for some people.

I have a small intuition that a fine crush may impact the way that the grain bed releases wort when squeezing and improve lauter efficiency, but I'm still trying to plan an experiment for that.

Totally agree! That is why I decided that instead of doing a full volume BIAB mash that I would hold back 2.75 gallons when the grain was already saturated to batch/dunk sparge with a good stir, long hang, and death grip squeeze. I feel like most of my points came from the squeeze. I just got a great pair of hot hand oven gloves from BBB and they worked awesome.

 

[Morrey]

LOL! Great info on the HG beers. I will have to keep that in mind if I give one a try.

Morrey,

Do you find that your mill bogs down if you just fill the hopper and hit the drill with it?

It sure does, BigJoe. If I fill up the hopper first, the drill has to really torque hard and jumps hard into the grind. Then I have to stay hard into the power band to keep the grind going w/o bogging down. I have found that if I start the rollers very slowly as wife starts grain flow into hopper, it all starts smoothly. It is kind of an art knowing how fast to run the drill and she has learned how fast to feed grains into the mill. If we go slowly and don't get too fast, the grind is perfect meaning my efficiency is consistently high.

 

[doug293cz]

Just brewed an Dry Irish Stout yesterday and ran into a good problem, but was not ready to deal with it. So, I want to try to learn from this experience.

Dry Irish Stout
8.25lbs. Maris Otter
2.25lbs. Flaked Barley
1.25lbs. Roasted Barley

Predicted OG 1.058 for 5.5 gallons @ 75% efficiency

Actual OG was 1.068 for 5.75 gallons

Questions
1) I calculated efficiency as 91.6%. Which efficiency is this (Brewhouse, Mash, or other)?

2) If I would have topped off to bring OG down to where it needed to be my fermenter would have been way to full. What do you do with the extra?

3. I am using a corona style mill that isn't precise at all. Should I start planning on 80-85% efficiency or still 75% as I have been?

I think my crush was pretty fine. Should of taken a pic. I squeezed the bee-jesus out of the bag and then did a dunk/batch sparge/ with a good stir, let rest 5 min then drained and squeezed again.

Here were my refract readings

Started with 5 gallons
First runnings - Yield 4 gal @1.081
Second runnings - Yield 2.75 gal @ 1.036
Pre Boil - 6.75 gal @ 1.062


I guess I got lucky this go round with crushing finer.

Unfortunately, your numbers are too good to be true. For a grain bill with a typical composite extract potential of 80.1% (fine grind, dry basis) equivalent to 37 ppg, the highest possible first runnings gravity for 11.75 lbs in 5 gal of strike water is just under 1.073. To get 1.081 with 5 gal of strike water would require a grain extract potential of 90.8%, or 41.9 ppg. Some wheat malts have potentials of 39 ppg, but barleys top out at 38 ppg (including Maris Otter.) With your grain bill you are likely to be in the 36 - 37 ppg range. To get 1.081 first runnings from 11.75 lbs of grain @ 37 ppg, your strike water volume would have to have been only 4.41 gal. I outline how to calculate max first runnings gravity here: https://www.homebrewtalk.com/showpost.php?p=7625876&postcount=9

So, you must have measurement errors in volumes and/or SG's. One thing you have to watch when using a refractometer is water evaporation from small, hot samples. Evaporation will cause the reading to be higher than the bulk of the wort. One way to avoid this is to take a sample of about 1 oz, place it in a closed container to cool to where evaporation won't be too rapid, and then use a dropper to put a sample on the refract.

Brew on

 

[dmtaylor]

I hadn't done the math previously, but I can see now what doug is saying and I agree.... something got measured wrong someplace, whether it's the gravity or the volumes or who knows what. It is still likely that your efficiency was quite high, but just not quite as high as we originally thought. Maybe mid 80s? That's just a guess. Data from more subsequent batches will be needed before you can totally dial this in. But no worries, you'll get there.

Brew on indeed!

 

[TheMadKing]

If I would have added anymore water there wouldn't have been enough room in the fermenter. What do others do with the extra wort that doesn't fit?

That by itself is a problem. If your fermentor is so full you can't add ANY water to it, you don't have enough headspace and will eventually have a blowout. Get yourself a 6 gallon bucket, or a big mouth bubbler, and you should always have enough headspace. It doesn't take much water to drop your gravity significantly, only a couple quarts will do it.

On my system, I make 5.3 gallon batches and ferment in a 7 gallon big mouth

 

[BigJoeBrew]

That by itself is a problem. If your fermentor is so full you can't add ANY water to it, you don't have enough headspace and will eventually have a blowout. Get yourself a 6 gallon bucket, or a big mouth bubbler, and you should always have enough headspace. It doesn't take much water to drop your gravity significantly, only a couple quarts will do it.

On my system, I make 5.3 gallon batches and ferment in a 7 gallon big mouth

Mad King I added 2 quarts of top off water at the end which brought me down to my 1.068 gravity. I was hovering around 5.5-5.7 gallons (don't have clear markings for those) in the 6.5 gallon fermentor and I thought if I don't quit this sucker is gonna blow and make a mess. I agree that a bigger fermentor would solve that problem.

Unfortunately, your numbers are too good to be true. For a grain bill with a typical composite extract potential of 80.1% (fine grind, dry basis) equivalent to 37 ppg, the highest possible first runnings gravity for 11.75 lbs in 5 gal of strike water is just under 1.073. To get 1.081 with 5 gal of strike water would require a grain extract potential of 90.8%, or 41.9 ppg. Some wheat malts have potentials of 39 ppg, but barleys top out at 38 ppg (including Maris Otter.) With your grain bill you are likely to be in the 36 - 37 ppg range. To get 1.081 first runnings from 11.75 lbs of grain @ 37 ppg, your strike water volume would have to have been only 4.41 gal. I outline how to calculate max first runnings gravity here: https://www.homebrewtalk.com/showpost.php?p=7625876&postcount=9

So, you must have measurement errors in volumes and/or SG's. One thing you have to watch when using a refractometer is water evaporation from small, hot samples. Evaporation will cause the reading to be higher than the bulk of the wort. One way to avoid this is to take a sample of about 1 oz, place it in a closed container to cool to where evaporation won't be too rapid, and then use a dropper to put a sample on the refract.

Brew on

Doug that makes sense. I will have to use your system next time and take a reading, and then try what I did and see if there is a difference, which I am sure there will be. I did measure with my refractometer and hydrometer right before pitching yeast. 66ish degrees and both were reading 1.068. I measure my strike water in my Ale Pail bucket, with the manufacturers markings, so how ever accurate those are, and I am sure I can be off pretty significantly. I bet it was a combination of all of my calculation together. I was just really astonished that I was getting such high gravity readings for the amount of wort I felt like I had. Before this point I have always fell short of my gravity reading or full volume or both. So, I was glad have the opposite problem this time around.

Much appreciated for helping improve my techniques.

 

[doug293cz]

Mad King I added 2 quarts of top off water at the end which brought me down to my 1.068 gravity. I was hovering around 5.5-5.7 gallons (don't have clear markings for those) in the 6.5 gallon fermentor and I thought if I don't quit this sucker is gonna blow and make a mess. I agree that a bigger fermentor would solve that problem.



Doug that makes sense. I will have to use your system next time and take a reading, and then try what I did and see if there is a difference, which I am sure there will be. I did measure with my refractometer and hydrometer right before pitching yeast. 66ish degrees and both were reading 1.068. I measure my strike water in my Ale Pail bucket, with the manufacturers markings, so how ever accurate those are, and I am sure I can be off pretty significantly. I bet it was a combination of all of my calculation together. I was just really astonished that I was getting such high gravity readings for the amount of wort I felt like I had. Before this point I have always fell short of my gravity reading or full volume or both. So, I was glad have the opposite problem this time around.

Much appreciated for helping improve my techniques.

I wouldn't trust the pail markings, as those are only approximate. Best (easy) way to measure volumes is get a 24" steel ruler or make your own dipstick. Add a half gallon of water at a time to your BK from a calibrated measuring vessel, and mark your dipstick. With a ruler you can just add a known number of gallons to your BK, and divide the depth measurement by the number of gallons to figure out the inches/gallon calibration for your ruler (this only works for straight sided vessels.) If you don't have a know calibrated measuring vessel, but have an accurate scale (which is also handy for weighing grain), then you can weight out a 1/2 gal or a gal at a time to do you dipstick/ruler calibration. Water weighs 8.33 lbs/gal at 68˚F.

Brew on