Efficiency and flavour extraction

[Agentgonzo]

Efficiency comes up a lot as it's very easy to measure sugar extraction from your mash/sparge/process. But it's a lot harder to measure flavour extraction.
I've been thinking about it for a while and @peebee made a similar comment here

What happened to flavour? Surely for that a low efficiency is better to gain more flavour from more ingredient?

In my mind, there is no clear link between sugar extraction from the mash (what efficiency measures) and flavour extraction. I don't see any particular reason why they should both be directly related.

So does anyone have any idea whether they are linked, and if so in what way?

To put it another way, if you were to do two brews that were identical except for the efficiency (determined by your mash pot, BIAB, sparge etc) and let's say one had a 60% efficiency, and the other had a 90% efficiency, but you compensated for the difference in efficiency by adding more grain (let's say it's a SMASH with just pale malt for sake of argument) to the 60% efficiency brew, would you expect them to taste the same? Would you expect the 60% efficiency brew to have more malt flavour because it had more grain in it even though both ended up at the same OG? Or would you expect the 60% brew to have less flavour because flavour is extracted less than sugar?

I'm expecting very few answers to be based in actual evidence and most in guesswork, but if people have had experience from doing different brews like the above it would be really interesting to hear.

 

[The Baron]

I agree I can not see any relation to flavour and brewhouse efficiency or if there is because of the slightly higher gravity of the wort it must be minimal

 

[dmtaylor]

Many years ago I used to average >90% efficiency. I thought my beers tasted thin. I opened the gap slightly on my mill and have been getting 82% ever since. No longer have a thin flavor IMO. I'll admit I might be imagining all of this. But I might not.

 

[Pennine]

It's a good question, I would think it does impact flavour. And it's making me rethink my recent change to milling the malt twice for efficiency as I have also been feeling like my beers are thin.

 

[Stu's Brews]

My assumption (not at all based on any actual knowledge) would be that the rate of flavour extraction would be different to the rate of sugar extraction and that each flavour compound would have it's own unique extraction rate.

I suspect that temperature, mash thickness, grain crush, pH would all effect the rate of flavour extraction in the same way they effect the mash efficiency; but again I'd assume that it would be a different relationship for each flavour compound.

Haven't a clue as to how different the rates would be and whether there is any way to directly link the flavour and mash extraction rates though.

 

[Sadfield]

Some observations.

Grains are malted whole, so more of the desired flavour compounds created would likely be on the exterior of the grain and extracted quite quickly.

There's a conversion and saccharification process before extraction of sugars, which possibly breaks any relationship between flavour and sugar.

More grain would give more flavour. However, if we assume the above and flavour is extracted quicker, more grain would also retain more of that initially flavoursome liquor.

I suspect there's a sweet spot of not under or over sparging. Sparge too long and there's a diminishing return of sugar whilst diluting flavour.

Ideally close to perfect mash efficiency is desired, getting maximum yield of sugar and flavour. Now, if only there was a way to concentrate flavour and sugars after sparging, by removing H2O?

 

[Hazelwood Brewery]

“Flavour” is complex and there are far too many variables at play to consider the wider question but if you focus on the flavour directly linked to sugars you might stand a chance of coming up with something - probably still tenuous and not necessarily linked to efficiency specifically.

Having said that, I’ll give it a go . If we assume (reasonably) the malt has flavour compounds beyond sugars then more means more and adding more grain to compensate for low efficiency is adding more of those flavour compounds as well as more sugar.

 

[LeeH]

Hop efficiency is also overlooked. And hops can easily be the higher cost.

 

[Sadfield]

more grain to compensate for low efficiency is adding more of those flavour compounds as well as more sugar.

Efficiency decreases with higher grain mass though. More is more, but harder to extract.

 

[Agentgonzo]

Hop efficiency is also overlooked. And hops can easily be the higher cost.

Hops are done separately and don't contribute to the OG/FG. So you tend to not adjust hops based on brewhouse/mash efficiency.

 

[hoppyscotty]

Are you not mixing your drinks to a certain extent?

Mash efficiency is about extraction of starch from the grain. But once you've extracted the starch then the enzymes convert the starch into the simple and fermentable sugars and the complex and non fermentable sugars. Its the latter that really delivers flavour and body in the resulting beer and the former that delivers alcohol...which I guess contributes to flavour too but I never think of the alcohol content in that way.

So the flavour of your final beer is somewhat independent to your mash efficiency in my mind. You're main focus should be not on mash efficiency but on getting the correct blend of simple and complex sugars post conversion which really boils down to mash temperature.

Have I got this wrong?

 

[Agentgonzo]

So the flavour of your final beer is somewhat independent to your mash efficiency in my mind.

That was literally the question I was asking.

Have I got this wrong?

I think so.
The mash (and sparge) doesn't just convert sugars and extract them into the wort. It also extracts a whole host of other flavour compounds. And I was wondering to what degree the various different processes (which we normally measure in mash/brewhouse efficiency) affect the amount of these other flavours that you extract from the grain.

 

[hoppyscotty]

Ah gotcha. But you also need to be careful as there are also, I believe, some nasties in the grain you don't want, or at least want to keep at relatively low concentrations. I was talking to a chap a few weeks ago who's had a career with the big beer companies and he said in their systems they would sparge until sparge runnings got to 1.030 and they would stop. the reason they stopped at that point is that below 1.030 you start pulling out some undesirable compounds from the grain husks that are detrimental to flavour and other downstream processes. I mentioned to him I usually don't go beyond 1.010 sparge runnings and he said for homebrew that is probably correct, though without proper lab analysis it is hard to establish what the correct level is for any given process, but said I shouldn't go much lower than 1.010. More recent batches I've been hitting pre-boil volume and getting down to about 1.012 or 1.025 gravity sparge runnings so have been leaving it at that and not being tempted to continue the sparge and get more volume.

 

[Pennine]

Ah gotcha. But you also need to be careful as there are also, I believe, some nasties in the grain you don't want, or at least want to keep at relatively low concentrations. I was talking to a chap a few weeks ago who's had a career with the big beer companies and he said in their systems they would sparge until sparge runnings got to 1.030 and they would stop. the reason they stopped at that point is that below 1.030 you start pulling out some undesirable compounds from the grain husks that are detrimental to flavour and other downstream processes. I mentioned to him I usually don't go beyond 1.010 sparge runnings and he said for homebrew that is probably correct, though without proper lab analysis it is hard to establish what the correct level is for any given process, but said I shouldn't go much lower than 1.010. More recent batches I've been hitting pre-boil volume and getting down to about 1.012 or 1.025 gravity sparge runnings so have been leaving it at that and not being tempted to continue the sparge and get more volume.

I think that is what Agent is getting at, @foxy mentioned in another thread rather than sparging, just increasing grain and then adding as much water to the mash as your unit allows and then pull the malt once the mash is done. This would lower efficiency but hopefully extract more positive flavour compounds. Might be worth trying out.

 

[Sadfield]

Surely it should be possible to get both high efficiency and flavourful beer? Isn't that what many commercial breweries do?

 

[Agentgonzo]

I think that is what Agent is getting at, @foxy mentioned in another thread rather than sparging, just increasing grain and then adding as much water to the mash as your unit allows and then pull the malt once the mash is done. This would lower efficiency but hopefully extract more positive flavour compounds. Might be worth trying out.

Thank you @Pennine - this is exactly what I was getting at.

eg,
you could brew Batch A with your normal mill gap, fly-sparge and have an efficiency of 80% and end up with an OG of 1.050
or you could brew batch B with a wide mill gap and do no-sparge and have (say) an efficiency of 60%, but compensate for this with a higher grain bill and get an OG of 1.050.


Two beers, same OG, same percentage of each grain in the grain bill (and you could do many many different processes with the same grain bill proportions and an OG of 1.050). But how would the batch A and Batch B (or C, D...) differ in flavour.
I don't think many people have tried this or know for sure.

Might be worth trying out.

Indeed. I was wondering whether anyone had done this (rather than just 'guessing' that it might be the case)

 

[hoppyscotty]

Of course brulosophy has done an experiment on this or something along these lines. Unsurprisingly the results were that you can't tell the difference.

 

[Agentgonzo]

Of course brulosophy has done an experiment on this or something along these lines. Unsurprisingly the results were that you can't tell the difference.

I know they've done ones with mash temperature etc, but I wasnt' aware that they had done one on this topic where you aim for the same OG but modifying the efficiency.
A lot of their experiments end up not showing significance. I guess that all the minor tweaks that people make to their processes don't end up having a noticeable difference over the end product. It doesn't spoil the fun though!

 

[foxy]

Of course brulosophy has done an experiment on this or something along these lines. Unsurprisingly the results were that you can't tell the difference.

True he also states that when making a beer below a gravity of 1,055 he uses the full volume mash. George Fix and John Palmer also prefer the no sparge stating that there is a difference. As mentioned before, sparging in the history of brewing is new, saves time and effort getting a full volume of a set beer first crack instead of carrying on with 2nd 3rd and even 4th runnings.
I suppose at the end of the day the yeast plays a big role in the final end product of flavour through the esters and the transforming of the sugar to alcohol.

 

[Pennine]

And then there is the partigyle which seems like brewer's were mixing first and second runnings to get the right flavour which would also indicate something was missing in the straight second runnings.