Mash Efficiency...when is enough truly enough

[Morrey]

I do propane fired BIAB with a mesh basket and have dialed in my process (including grind) to the point I can nail 87% conversion efficiency like money in the bank. This consistency is key in recipe design and repeatability in results.

I usually do 75 minute mashes in a kettle insulated with a mover's blanket, and only stir once at the mid-mash point to conserve temperatures by limiting the time I uncover my kettle. Given that I am getting 87% as is, how much more efficiency is there to be gained?

I figure to get higher efficiency, some sort of mash recirculation system would be needed. Then temperature control comes into play...and on and on and on. Long story short for those who are willing and able to make recirculation happen, how much more is available? I know 87% is the baseline, and how much more can be added?

Just asking this question knowing full well I seriously doubt it is worth it to make any changes at this point. Curious minds wanting to know...nothing more.

 

[myndflyte]

I guess you got to ask yourself if you want to put in the time and money to fine tune equipment to eek another few percentage points out. Then compare that to how much you'd actually be saving in grain when your efficiency goes from 87% to 92%. In my eyes, not worth it. You've hit quite a high mark so just keep doing what you're doing.

 

[Smellyglove]

You said mash conversion, but I guess you mean preboil efficiency?

If you're happy with your current setup I wouldn't try to chase any more. You have a nice headroom for those bigger beers aswell. It's not all about the efficiency, but also quality. If you don't know what you're doing quality wise a great efficiency can make your beer taste not as good as it could be. It's easier to get just a higher efficiency than it is to implement quality with that efficiency.

 

[schatzke]

If I was you I wouldn't think about conversion any more. 87% is a great figure, sure it could be a bit higher, but having your process that consistent is something that many brewers would envy. Stick with what works and put your time and effort into other aspects of your brewing process.

 

[lump42]

If you have your equipment dialed in, I wouldn't worry about it. 87% is a very respectable efficiency. Personally I'm happy with ~73% average efficiency.

 

[Miraculix]

Sorry, but I have to ask.

Did anyone of you guys who have just given an answer actually read his last paragraph?

 

[Smellyglove]

Sorry, but I have to ask.

Did anyone of you guys who have just given an answer actually read his last paragraph?

Why do you ask? I feel he got his thought confirmed.

 

[Morrey]

You said mash conversion, but I guess you mean preboil efficiency?

Yes, preboil....correct. I call it mash (conversion) efficiency but I may be calling it the wrong thing. I quit messing with BH since I will have some losses in hoses, trub in kettle, etc, so I look at preboil as a way to gauge consistency. I realize BH is probably the biggest report card, but I really have not focused on that in awhile.

Like I figure, it is highly likely I may be able to eek out a few more points recirculating....just wondering how much others that recirculate may consider I could gain over and above my current process. I am close to 100% sure I am not going to start modifying my equipment and process, just wondering what others have gained by recirculation.

 

[day_trippr]

All things equal I don't think recirculation actually matters much wrt extract efficiency. That's more a reflection of mash pH, how homogenous the mash bed was wrt density and temperature, and how effective the sparge is.

Fly sparging in a conventional rig can easily hit in the 90s for extract efficiency, but then run the risk of excessive silicates and tannins in the boil. According to BS2 and CV occasionally my end-of-sparge runnings have been close to cut-off (1.006 SG and/or 5.6 ph) with an expected pre-boil volume with extract efficiencies in the low 90s.

My expectation is BiaB would never get into that situation aside from excessive sparging...

Cheers!

 

[Morrey]

All things equal I don't think recirculation actually matters much wrt extract efficiency. That's more a reflection of mash pH, how homogenous the mash bed was wrt density and temperature, and how effective the sparge is.

Fly sparging in a conventional rig can easily hit in the 90s for extract efficiency, but then run the risk of excessive silicates and tannins in the boil. According to BS2 and CV occasionally my end-of-sparge runnings have been close to cut-off (1.006 SG and/or 5.6 ph) with an expected pre-boil volume with extract efficiencies in the low 90s.

My expectation is BiaB would never get into that situation aside from excessive sparging...

Cheers!

Excellent information and lots of what you just said made me realize I may not get any gains with recirculation...at least with BIAB as my process. Not that I plan to change anything...I just wanted to know what would be out there if I looked around.

Some time ago, Mongoose33 prompted me to experiment with a "pour over" rinse type sparge with BIAB. I use full volume strike water (adjusted with Bru'n Water) and my grains (ground with MM3) are mashed in an Arbor Fab mesh basket. I raise the basket with a chain hoist, press with a press plate...rough up the grain bed, then slowly pour over 1/2 gallon of distilled water back over the grain bed to rinse. A final press leaves less than .5 gallons of absorption in a 10# grain bill, so I think I am reclaiming all of the wort I can squeeze out. Our tests showed there are enough sugars in the rinse sparge to make this process worthwhile, so I increase my boil time slightly to get rid of the excess sparge water so I can mash full volume.

I outlined all of this since you mentioned that sparging may have more of an impact than recirculation. I'm glad you pointed this out to me and I appreciate your input. With 87% eff in the bank consistently, I am content.

 

[Dcpcooks]

You’d probably loose a point or two in BH efficiency with the additional pump, coil and hoses attached. That would likely offset any gains picked up from recirculation.

When you figure in a coarser grind to allow for safe easy recirculation you may see a bit more loss as well.

When you calculate the cost of the equipment upgrade vs the cost of grain you’d probably never recoup the cash outlay.

If it ain’t broke.....

 

[Morrey]

You’d probably loose a point or two in BH efficiency with the additional pump, coil and hoses attached. That would likely offset any gains picked up from recirculation.

When you figure in a coarser grind to allow for safe easy recirculation you may see a bit more loss as well.

When you calculate the cost of the equipment upgrade vs the cost of grain you’d probably never recoup the cash outlay.

If it ain’t broke.....

....I am on the same page with you, DCP.

 

[Lefou]

If you have your equipment dialed in, I wouldn't worry about it. 87% is a very respectable efficiency. Personally I'm happy with ~73% average efficiency.

Extending my mash and keeping better track of the temperatures bumped my efficiency up almost 10 points. When first starting out with all grain, I was getting 68-70.
Between 70 and 78 on a regular basis would satisfy me, but the biggest issue is my grind consistency.

 

[Miraculix]

In a recent experiment I went above 90% brewhouse efficiency by mashing for two hours. Don't know if it is worth it though as I was at 85% before anyway.

 

[Morrey]

In a recent experiment I went above 90% brewhouse efficiency by mashing for two hours. Don't know if it is worth it though as I was at 85% before anyway.

Interesting. I have basically upped my mash time to 75 minutes to get more flavor from the grain thinking that complete conversion may require only 30 minutes or so. RM-MN had some pretty detailed threads on this so we should revisit his review and add our findings once complete.

I think on my next mash on a "standard or house" beer in which I get 87% like clockwork, I am going to try a 120 minute mash and compare conversion efficiency numbers. Cant hurt a thing to try, and with warmer weather aiding temps stability in my insulated kettle, I can hold temps close for that long. I am interested in seeing if a 120 minute mash brings me up from 87% which is very standard for me with a 1.050 - 1.060 range beer.

Thanks for the post!

 

[Miraculix]

Interesting. I have basically upped my mash time to 75 minutes to get more flavor from the grain thinking that complete conversion may require only 30 minutes or so. RM-MN had some pretty detailed threads on this so we should revisit his review and add our findings once complete.

I think on my next mash on a "standard or house" beer in which I get 87% like clockwork, I am going to try a 120 minute mash and compare conversion efficiency numbers. Cant hurt a thing to try, and with warmer weather aiding temps stability in my insulated kettle, I can hold temps close for that long. I am interested in seeing if a 120 minute mash brings me up from 87% which is very standard for me with a 1.050 - 1.060 range beer.

Thanks for the post!

People (including myself) often make the mistake that a conversion of the starch in solution (iodine test negative) means that all starch is converted.

It just shows you that the starch in solution is converted. All the starch that is still not gelatinized doesn't show up in this test and surely isn't converted. This explains the poorer efficiency of 30min mashes compared to longer mashes.

By extending the mash length we basically provide a longer time for the starch to be gelatinized and converted afterwards.

 

[Hwk-I-St8]

I'm no expert, but I do have thoughts on efficiency.

First, while knowing your conversion, lauter, etc efficiency is important for trouble shooting efficiency issues, brewhouse efficiency is what really matters in recipe building and planning.

Second, consistency is key. If you're never going to brew anything above 6% and you can consistently nail 55% brewhouse efficiency, you'll be fine. You'll probably spend an extra $5 per batch, but it's not a big deal. That being said, it's not hard to get much better efficiency than that.

Third, if you want to brew big beers (12% RIS for example), you need to have decent efficiency. If you can brew a 6% IPA at 70% or a little higher (BH), then you can brew the big beers. Trying to brew a huge stout when you're only getting 60% on your IPAs is can be a problem. The issue is that the larger grain bill drops your efficiency, which is already low. So you add even more grain to compensate and that drops your efficiency more, so you add more grain and the cycle continues. You can get into a situation where you can't get there from here without making significant process changes or supplementing with extract.

So for those reasons, anything 70% or higher brewhouse efficiency is high enough in my opinion. If you never want to brew big beers, you don't even need that high.

 

[RM-MN]

Extending my mash and keeping better track of the temperatures bumped my efficiency up almost 10 points. When first starting out with all grain, I was getting 68-70.
Between 70 and 78 on a regular basis would satisfy me, but the biggest issue is my grind consistency.

Extending the mash period is a method of dealing with a less than adequate milling. More time lets more starch become gelatinized.

In a recent experiment I went above 90% brewhouse efficiency by mashing for two hours. Don't know if it is worth it though as I was at 85% before anyway.

Same answer as the above. If you can hold the mash temperature steady you can get good mash efficiency by extending the time or you can reduce the grain particle size to make the starches more readily available to the water. I prefer the finer milling.

People (including myself) often make the mistake that a conversion of the starch in solution (iodine test negative) means that all starch is converted.

It just shows you that the starch in solution is converted. All the starch that is still not gelatinized doesn't show up in this test and surely isn't converted. This explains the poorer efficiency of 30min mashes compared to longer mashes.

By extending the mash length we basically provide a longer time for the starch to be gelatinized and converted afterwards.

This is an important point. The conversion of starch to sugar is very quick so if your starch is gelatinized, it converts. The only time you should have starches in the wort is if your grains don't have sufficient diastatic power to do the conversion. Iodine tests should be done both with just wort and then with mostly grains. If you have starch in the wort it tells a different story than if you only have starch in the grains.

 

[Hwk-I-St8]

Extending the mash period is a method of dealing with a less than adequate milling. More time lets more starch become gelatinized.



Same answer as the above. If you can hold the mash temperature steady you can get good mash efficiency by extending the time or you can reduce the grain particle size to make the starches more readily available to the water. I prefer the finer milling.



This is an important point. The conversion of starch to sugar is very quick so if your starch is gelatinized, it converts. The only time you should have starches in the wort is if your grains don't have sufficient diastatic power to do the conversion. Iodine tests should be done both with just wort and then with mostly grains. If you have starch in the wort it tells a different story than if you only have starch in the grains.

I've never done an iodine test. I've read about them, but never felt the need to do it. Can you elaborate on your comments about starch in the wort vs starch in the grains? This is looking like one of those great opportunities to expand my knowledge....

 

[RM-MN]

I've never done an iodine test. I've read about them, but never felt the need to do it. Can you elaborate on your comments about starch in the wort vs starch in the grains? This is looking like one of those great opportunities to expand my knowledge....

Normally when the starch is gelatinized and the water is in the proper temperature range the conversion from starch to sugar is done by the enzymes nearly instantaneously. However, not all grains have sufficient enzymes left after the kilning to complete the conversion or if the temperature is outside the limits for the enzymes to work it is possible to extract the starch without conversion.

We expect our grains to be milled suitable to our style of mashing. If the grains are milled too fine for the conventional tun you may experience a stuck mash or stuck sparge. For this reason the grain is often milled a bit more coarse. Now you don't have a stuck mash but because of the size of the grain particles the water cannot get to all the starches to gelatinize them and those starches remain unconverted. This is where the mash efficiency comes from, the potential conversion to sugars compared to the actual conversion. With the grains milled for a conventional tun, there is likely unconverted starch left. This is where iodine will show you the color change.

When grains are milled extra fine or double milled the particle size is much smaller and more of the starch is exposed. If all of it gets gelatinized and converted, the iodine placed on the grains at the end of the mash will not change color. That would indicate complete conversion and the mash efficiency would be maximized.

 

[corax]

while knowing your conversion, lauter, etc efficiency is important for trouble shooting efficiency issues, brewhouse efficiency is what really matters in recipe building and planning.

Everyone's system and methods are different, but assuming I know what you mean by "brewhouse efficiency" (and I might not), then for me the opposite is true.

First, the terms as I use them:

Mash or System Efficiency: the actual pre-boil extract (points per pound per gallon) divided by the maximum possible pre-boil extract for the amount of grain used.
Brewhouse Efficiency: the actual extract going into the fermenter divided by the maximum possible extract for the amount of grain used.

There are a large number of variables that determine mash efficiency -- type of grain, coarseness of crush, mash conditions and methods, lautering methods, etc, etc -- and these can vary greatly from batch to batch. Wrangling these variables to the point where I can get batch-to-batch predictability is the key to successful recipe design for me.

If and when I get mash efficiency dialed in and predictable, then estimating brewhouse efficiency is trivial, because there are only two additional variables needed: the concentration of the wort due to boiling, and the amount of wort lost between kettle and fermenter-- both of which are batch-to-batch highly reproducible and predictable.

 

[Hwk-I-St8]

Everyone's system and methods are different, but assuming I know what you mean by "brewhouse efficiency" (and I might not), then for me the opposite is true.

First, the terms as I use them:

Mash or System Efficiency: the actual pre-boil extract (points per pound per gallon) divided by the maximum possible pre-boil extract for the amount of grain used.
Brewhouse Efficiency: the actual extract going into the fermenter divided by the maximum possible extract for the amount of grain used.

There are a large number of variables that determine mash efficiency -- type of grain, coarseness of crush, mash conditions and methods, lautering methods, etc, etc -- and these can vary greatly from batch to batch. Wrangling these variables to the point where I can get batch-to-batch predictability is the key to successful recipe design for me.

If and when I get mash efficiency dialed in and predictable, then estimating brewhouse efficiency is trivial, because there are only two additional variables needed: the concentration of the wort due to boiling, and the amount of wort lost between kettle and fermenter-- both of which are batch-to-batch highly reproducible and predictable.

I would agree, but when I build a recipe in Brewer's Friend, I'm looking at how much grain goes in, how much water goes in, how much wort goes into the fermenter. That's brewhouse efficiency. Sure, the boil off and kettle/trub losses are pretty easy to manage and predict, but the bottom line is that they're still relevant and need to be accounted for so taht is what I'm looking at when building a recipe.

The intermediate values are good to know if the brewhouse efficiency is less than optimal, but I don't look at conversion efficiency, lauter efficiency, or mash efficiency when building a recipe, which was my point when I said "brewhouse efficiency is what really matters in recipe building and planning"

 

[corax]

I would agree, but when I build a recipe in Brewer's Friend, I'm looking at how much grain goes in, how much water goes in, how much wort goes into the fermenter. That's brewhouse efficiency. Sure, the boil off and kettle/trub losses are pretty easy to manage and predict, but the bottom line is that they're still relevant and need to be accounted for so taht is what I'm looking at when building a recipe.

The intermediate values are good to know if the brewhouse efficiency is less than optimal, but I don't look at conversion efficiency, lauter efficiency, or mash efficiency when building a recipe, which was my point when I said "brewhouse efficiency is what really matters in recipe building and planning"

Fair enough -- the difference is mainly in our planning methods.

I do my own calculations, and focus on hitting the target pre-boil gravity. Two reasons for this: first, as mentioned before, everything downstream of that is pretty much constant from batch to batch. But second, and importantly, it's a critical control point, and IMO the best point to make adjustments to hit your desired final gravity (eg, more water or adjusted boil time).