Which efficiency number is most important?

[SpanishCastleAle]

The point is that you shouldn’t be adjusting your grain bill because of something like boiling off too much or too little. If your mash efficiency is in-line and you still have a problem with OG you should be looking somewhere else in your process, not just throwing more or less grain into your tun.

If you use whole hops they will absorb some wort so your brewhouse will ALWAYS be less than your mash efficiency (same gravity but less volume means less total points...i.e. lower efficiency). If you don't account for this your OG will be off. The beauty of brewhouse efficiency is that it won't matter if you boiled off too much (which would cause the OG to be too high)...you can just add water and your OG will be right where it's supposed to be. It has nothing to do with adjusting your grain bill to adjust for boiling off too much/too little...it has everything to do with adjusting your grain bill to account for losses...so your OG is right where you want it at your target fermenter volume.

 

[SpanishCastleAle]

Mash efficiency is important because it is specific to one part of the process. Brewhouse efficiency it too broad and covers too many variables to be used for making adjustments.

Probably a bad analogy but:

You are driving from Atlanta to LA...it would be nice to know how long it takes to get from Atlanta to Birmingham...then Birmingham to the Texas border...and so on so you can plan hotel/motel stays. But the 'bottom line' is how long it takes to get from Atlanta to LA. You might get slowed by a traffic accident or a flat tire or something else. Just adding up the theoretical travel times between cities and adding them all up won't account for these 'losses' (some of which are unavoidable).

Mash efficiency is just one 'stop' along the way (and a very important one). Brewhouse efficiency encompasses the whole process.

 

[Echo2112]

Good God, I come back in to check out my post and WOOSH!

Right over my head.


I am gonna have to go back and re-read all of this stuff a few dozen times to see if I can make sense of some of this.

 

[SpanishCastleAle]

Echo,
In addition to reading it...try to do the math yourself and I think you'll get a better understanding of it. Everybody has their own way of looking at things. I think we ('we'...meaning me and those having this last little discussion) probably agree on more than we disagree on this but we're probably approaching it from different perspectives.

Most of the difference between my mash efficiency and brewhouse efficiency is because I use whole hops. Whole hops absorb a significant amount of wort. If you had 5 gallons of 1.050 wort and then added hops, let them soak, and then removed them...they would absorb some wort and your volume would no longer be 5 gallons. But your gravity would still be 1.050. You just suffered a loss that your mash efficiency did not account for (because it happened afterwards). Now you'll have to add water to get back up to 5 gallons but that will lower your gravity. So you missed your target OG because you didn't account for losses that occured after the mash. Brewhouse efficiency takes ALL of this into account so you get your exact target OG at your exact target volume.

 

[Echo2112]

Thanks, that helps me understand things.

So what do you think is the best method for determining efficiency? Should I go with the numbers that Beer Smith is giving me? Or should I use the numbers and formula from Palmer's "How to Brew"?

I guess I can use both, but I am concerned about which is most accurate.

I realize one mistake I made was taking the pre-boil gravity while the wort was still pretty hot, so that threw the numbers off there, but my other numbers for the OG into the fermenter were dead on for temp, and that gives me an efficiency of 84%. I can live with that for now, next time, I know to refine a few steps.

Now,

As I understand it, you are using the "Into fermenter" gravity to help determine your grain bill, since you have a fixed variable with the volume of liquid, and you then insert the variable that is your target OG, and then use that to determine a grain bill.

That seems contradictory to what I have read, since as I understand it, the efficiency of your mash has an impact upon the amount of sugars in the wort pre-boil, and that during the boil, you are losing volume (Loss of H20) but the end result should be an increase in the concentrations of sugars, since you have not boiled them away, just the water. Which will result in an OG higher than the pre-boil gravity.

I would think that if you are less efficient in the mash, and you are correcting by adding DME to the boil to bring up the pre-boil gravity, you could be better served by correcting your mash schedule and try to get more sugars from the wort, rather than spending more money to cover for the lack of conversion.

Unless, of course I am still not understanding, which is possible.

 

[Echo2112]

Echo,
In addition to reading it...try to do the math yourself and I think you'll get a better understanding of it. Everybody has their own way of looking at things. I think we ('we'...meaning me and those having this last little discussion) probably agree on more than we disagree on this but we're probably approaching it from different perspectives.

Most of the difference between my mash efficiency and brewhouse efficiency is because I use whole hops. Whole hops absorb a significant amount of wort. If you had 5 gallons of 1.050 wort and then added hops, let them soak, and then removed them...they would absorb some wort and your volume would no longer be 5 gallons. But your gravity would still be 1.050. You just suffered a loss that your mash efficiency did not account for (because it happened afterwards). Now you'll have to add water to get back up to 5 gallons but that will lower your gravity. So you missed your target OG because you didn't account for losses that occured after the mash. Brewhouse efficiency takes ALL of this into account so you get your exact target OG at your exact target volume.

So could you not compensate for your whole hops by adjusting how much volume is left at the end of the boil? If you know that the hops are going to remove a certain amount of volume, wouldn't be better to adjust the boil times to allow for the loss, so when you transfer to the fermenter, you hit both the target OG and the target volume?

 

[AnOldUR]

Brewhouse efficiency is an important general tool that lets you know that there may be a problem in your process. Mash efficiency specific tool that lets you know if you are on the right track.

If I had the choice of only knowing only my mash or brewhouse efficiency I would choose to know the mash number.

If the mash efficiency is good and you adjust your boil for the correct OG the only potential problem is less volume. This could be due to hop absorbsion, excess break or loss of volume when trying to strain your wort into the fermenter. Although your brewhouse efficiency may suck and you have less beer, you still have good beer.

If you only look at brewhouse efficiency and adjust your boil for your desired OG, you still have the potential for over sparging and bad beer. Or you may be only fooling yourself with tons of break material and hop residue that will settle to the bottom of your fermenter and won’t actually give you any more beer in the end.

 

[AnOldUR]

If you use whole hops they will absorb some wort so your brewhouse will ALWAYS be less than your mash efficiency (same gravity but less volume means less total points...i.e. lower efficiency). If you don't account for this your OG will be off.

No. Your volume will be off. Your OG will only be off if you are foolish enough to use top off water.

The beauty of brewhouse efficiency is that it won't matter if you boiled off too much (which would cause the OG to be too high)...you can just add water and your OG will be right where it's supposed to be

Or you could adjust your boil for a reasonable amount of loss.

It has nothing to do with adjusting your grain bill to adjust for boiling off too much/too little...it has everything to do with adjusting your grain bill to account for losses...so your OG is right where you want it at your target fermenter volume.

So you would risk over sparging or wasting grain to get your desired OG.

Probably a bad analogy but:

No, actually a good one. Your choice is to leave earlier to make up for any problems that might be encountered along the way. I’d rather adjust my route to avoid delays.

 

[AnOldUR]

. . . wouldn't be better to adjust the boil times to allow for the loss, so when you transfer to the fermenter, you hit both the target OG and the target volume?

No, you need a set boil time to get proper hop utilization and to remove unwanted compounds. If you want to hit the right volume you have to increase both your grain bill and the amount of sparge water used so that you have more going into the kettle. You have to keep that ratio right for proper mash efficiency. Your brewhouse efficiency may suck, but you'll have the right amount of beer and you'll have good beer.

 

[Echo2112]

Brewhouse efficiency is an important general tool that lets you know that there may be a problem in your process. Mash efficiency specific tool that lets you know if you are on the right track.

If I had the choice of only knowing only my mash or brewhouse efficiency I would choose to know the mash number.

If the mash efficiency is good and you adjust your boil for the correct OG the only potential problem is less volume. This could be due to hop absorbsion, excess break or loss of volume when trying to strain your wort into the fermenter. Although your brewhouse efficiency may suck and you have less beer, you still have good beer.

If you only look at brewhouse efficiency and adjust your boil for your desired OG, you still have the potential for over sparging and bad beer. Or you may be only fooling yourself with tons of break material and hop residue that will settle to the bottom of your fermenter and won’t actually give you any more beer in the end.

Thanks!

And just to be sure I have this set right, over sparging can lead to tannin extraction, which will give me flavors I don't want in my wort. And that normally will occur only after the pre boil gravity has gotten fairly low, under 1.010 or so correct?

I figured that you had to get the mash right, and shoot for a good efficiency in order to get the wort right for the type of beer you were making. While it is good to know how efficient you were at the end of the boil, the quality of the mash is a more important factor in determining the quality of the final product.

 

[SpanishCastleAle]

AnOldUR,
I think we are just going round and round and I'm pretty sure we agree on more than we disagree.

No. Your volume will be off. Your OG will only be off if you are foolish enough to use top off water.

Right...less volume means there was a loss. And mash efficiency did not account for it. So using just mash efficiency you either have less volume (but correct OG) or you had to add water to get your volume (but then your OG is off). If you had used brewhouse efficiency then BOTH your gravity AND your volume will be correct. If you happen to boil too much then your gravity WILL be too high using brewhouse...but you could just add the amount of water to get your volume and presto...your OG is right on target. Not so when using mash efficiency.

Side note: when I say 'add water' or 'boil longer' I'm just using them as an example.

Or you could adjust your boil for a reasonable amount of loss.

A haaaaa! THAT IS brewhouse efficency at work! You just fudged your numbers to get you closer to your actual brewhouse efficiency. Why fudge the numbers when you can determine exactly what it is and use that?

So you would risk over sparging or wasting grain to get your desired OG.

Nothing of the sort...I have no idea where you're going with that.

Your choice is to leave earlier to make up for any problems that might be encountered along the way. I’d rather adjust my route to avoid delays.

Now THAT would be analagous to wasting grain to get your target OG. So you just add a bunch of extra grain (analagous to 'leaving earlier') to avoid delays (analagous to 'losses')?

If you are adding some sort of 'adjustment' for any losses in your boil then you ARE using brewhouse efficiency...maybe you just don't know it.

 

[Echo2112]

No, you need a set boil time to get proper hop utilization and to remove unwanted compounds. If you want to hit the right volume you have to increase both your grain bill and the amount of sparge water used so that you have more going into the kettle. You have to keep that ratio right for proper mash efficiency. Your brewhouse efficiency may suck, but you'll have the right amount of beer and you'll have good beer.

Ok, this leads me to another question.

Everything I have read when it comes to brewing talks about an hour boil. The reasons seem to be hop utilization and a hot break to clarify the beer. But I have read some posts here where brewers have gone with 90 minute boils. Are the hops not being added until the boil has run for 30 minutes?

I have seen that mash times can vary, from either 60 to 90 minutes for better attenuation in the mash, but what about the longer boils? Bad idea, or just a matter of adjusting when you pitch your hops?

 

[SpanishCastleAle]

So could you not compensate for your whole hops by adjusting how much volume is left at the end of the boil?

Echo,
That's exactly what brewhouse efficiency does for you...and it also includes ANY other losses you may encounter. That's why I use brewhouse efficiency to determine my grain bill.

Any of these 'adjustments' being done to account for any loss after the mash are attempting to do the exact same thing as brewhouse efficiency. By making these 'adjustments' you are accounting for losses during the boil/chill/aeration/pour into the fermenter/etc. That's EXACTLY what brewhouse efficiency is...it takes ALL losses into account.

EDIT: Pils malts in particular need longer boils to drive off DMS. You can add the hops at 60 or 90...it will make a difference but utilization levels off quite a bit @ around 50-60 minutes (that's why 60 minutes is used so much...you don't get that much more utilization 'bang-for-your-buck' as you go over 60 minutes).

 

[AnOldUR]

I have read some posts here where brewers have gone with 90 minute boils. Are the hops not being added until the boil has run for 30 minutes

It can be done either way as long as you get the desired bitterness, but boiling the hops longer may add harshness. There is something to be said for not adding your hops until after hot break. It just means that you’ll need more hops. And don't overlook first wort hopping.

I have seen that mash times can vary, from either 60 to 90 minutes for better attenuation in the mash, but what about the longer boils? Bad idea, or just a matter of adjusting when you pitch your hops?

Grains like Pilsner need a longer boil for DMS removal, but some brewers just think they get a better end product with a longer boil. That's a whole different debate.



Edit:
Echo, if you have any questions and respect my opinion feel free to PM me. My patience has run out here. Otherwise, good luck with your brewing. You’re asking all the right questions and are off to a good start.

 

[Buford]

I do 90 minute boils myself. I add the hops 30 minutes into the boil. I was having DMS issues before with 60 minute boils. It means that you have to start with a greater volume, though, to account for boil-off.

 

[Kaiser]

This is a nice discussion and I’m glad I took a peek.

Until now I haven’t really understood why many brewers see the efficiency into the fermenter as more important as the efficiency into the kettle. Bobby did a good job explaining that to me. But to me the losses that make up the difference between the two are obvious and can easily be accounted for. I guess it largely depends how you set up your process.

But one big problem is the confusion that happens when we discuss efficiency problems. What efficiency are we discussing mash or BH? My opinion is that it should be mash efficiency by default b/c that provides a common reference which is only effected by mashing and lautering and not by amount of hops and practice of wort transfer. But b/c many brewers see BHE as most important they assume that BHE is discussed and may feel that their 70% BHE doesn’t stack up to someone else’s 85% ME.

I personally like to walk backwards from the fermenter volume/gravity and add the amount that I expect to leave in the kettle to get post boil. Then I know what ME I have gotten in the past on similar strength beers and know how much grain to use. I don’t like to use the boil-off to compensate although I have done that in the past. I’m also leaving a lot behind in the kettle to use for starters later. This alone makes it impractical for me to work with BHE.

Another problem with BHE is that it now also depends on the type of hops and hopping rate. So you can’t really assume the same BHE for an IPA with leaf hops and a Bock even if the gravity for both these beers is about the same and the expected ME is also the same. In this case I rather use the ME and adjust the amount of wort lost in the kettle by previous experiences with the amount/type of hops I’m going to use.

Kai

 

[GilaMinumBeer]

It can be done either way as long as you get the desired bitterness, but boiling the hops longer may add harshness. There is something to be said for not adding your hops until after hot break. It just means that you’ll need more hops. And don't overlook first wort hopping.

Grains like Pilsner need a longer boil for DMS removal, but some brewers just think they get a better end product with a longer boil. That's a whole different debate.



Edit:
Echo, if you have any questions and respect my opinion feel free to PM me. My patience has run out here. Otherwise, good luck with your brewing. You’re asking all the right questions and are off to a good start.

Another reason behind the 90 minute boil practice is to allow for break formation. Many believe that by allowing the break to form prior to hopping it will reduce the potential for hop compounds to get trapped up in the protein blobs.

 

[Kaiser]

I figured that you had to get the mash right, and shoot for a good efficiency in order to get the wort right for the type of beer you were making. While it is good to know how efficient you were at the end of the boil, the quality of the mash is a more important factor in determining the quality of the final product.

That is a good point that is often overlooked when comparing even mash efficiencies. You want to get a high efficiency from the conversion process and not so much from the lauter process. A high lauter efficiency has the potential of over sparging and with that excessive tannin extraction.

As I see it brew house efficiency can be written as the following equation:

BHE = ME * TE

ME is mash efficiency or efficiency into kettle
TE is transfer efficiency and I just made this up. It is the percentage of extract in the kettle that makes it into the fermenter and depends on your process, equipment and for many also the amount of trub.

Breaking this down further mash efficiency can be written as:

ME = CE * LE

CE is the conversion efficienct, A metric that I introduced here and which can easily be determined from the mash thickness and the gravity of the first runnings. It tells you how many percent of the starches have been converted to soluble extract. It depends on your mash parameters. (including quality of crush). You want this close to 100%. But for many brewers this is where most of the efficiency is lost.

LE is the lauter efficiency and it measures how many percent of the extract converted in the mash made it into the kettle. It depends on your sparging practice and parameters that effect how well the grain is rinsed. You want this to be reasonably high but not too high (85-90% for batch sparging and 90-95% for fly sparging are good numbers).

Just as an example from my last brewday. I made a pilsner with 4.3 kg of malt, 25 liter @ 11 Plato preboil and 17l @ 12.5 Plato in the fermenter. The BHE was 65% and here is where I lost the extract:

5% - didn’t get converted in the mash (95% conversion efficiency)
2 % - were left in wort that didn’t fit into the brew kettle (I’ll have to use less water next time)
11% - were left as extract in the wort that was held back by the spent grain (86% lauter efficiency)
17% - were left in the kettle and I froze this for later use in starters (so it’s not really lost)
65% - ended up in the fermenter.
------
100%


Kai

 

[Echo2112]

Wow, thanks for the post Kaiser!

Yet more info I need to try and wrap my head around.

 

[BierMuncher]

That's our Kaiser.

Doesn't speak up often...but when he does....:rockin:

 

[Kaiser]

Thanks,

I didn’t want to make things more confusing as this subject is already confusing enough. The point I wanted to make is that it should be less about what the final efficiency is but more where efficiency is lost and what would it take to fix that if there is a need for fixing it.

Kai

 

[SpanishCastleAle]

Great posts Kaiser.

But one big problem is the confusion that happens when we discuss efficiency problems. What efficiency are we discussing mash or BH? My opinion is that it should be mash efficiency by default b/c that provides a common reference which is only effected by mashing and lautering and not by amount of hops and practice of wort transfer. But b/c many brewers see BHE as most important they assume that BHE is discussed and may feel that their 70% BHE doesn’t stack up to someone else’s 85% ME.

Totally agree here...better to compare things that have less variables than more. As you pointed out, BHE is just ME with more variables...collectively calling them 'TE' works.

Another problem with BHE is that it now also depends on the type of hops and hopping rate. So you can’t really assume the same BHE for an IPA with leaf hops and a Bock even if the gravity for both these beers is about the same and the expected ME is also the same. In this case I rather use the ME and adjust the amount of wort lost in the kettle by previous experiences with the amount/type of hops I’m going to use.

Exactly...this was something I tried to point out but wasn't very successful I guess. Just changing your hops/hopping rate changed your BHE but not your ME. But as I was saying earlier...I think your "adjust(ing) the amount of wort lost in the kettle by previous experiences with the amount/type of hops I’m going to use." is just another way of saying BHE. You are adjusting your recipe/grain bill not because your ME changed but because your BHE changed. You basically estimated your term TE and multiplied it by your ME to get your 'adjusted ME'. I think this is were me AnOldUR were getting mixed up...he uses that equation like ME=BHE/TE where I use it like BHE=ME*TE. Same equation but we're after different variables in it.

 

[gxm]

An excellent discussion.
I've been calculating efficiency using a spreadsheet, and I just now realized that ME and BHE are different. I'd noticed that I've been losing sugars between the mash and the fermenter, and now it is more clear. Thanks all!