Should a thin, or a thick mash, give higher mash efficiency?

[peterpiper]

Just wondering if a thin mash, with smaller sparge, or a thick mash with larger sparge, should give greater mash efficiency (where final total water volume is the same).
If the ideal water:grain ratio, depends on diastatic power, how do you calculate it for a mix of grains?

During mash, sugar concentration in the saturated grain, will gradually equalise with that in the wort, so a thin mash with more dilute wort, should extract more of any sugars present.
A greater sparge volume, would wash off a higher proportion of the residual (surface) sugars.
But I can't imagine that sparging, even if done slowly, would remove much more sugar from within the grain.

It's said, that a thicker mash can be more efficient (or faster), due to the higher concentration of enzymes. With todays highly modified malts, is that still a factor, or does it only apply when using a high proportion of specialiaty malts or unmalted grain?
And could the enzymes all be washed from malted grain, leaving just starch behind, before there's been time for conversion?

Im guessing, that, given sufficient enzymes, the thin mash would be the more efficient overall. Yet brew software (default settings) often suggest using a thicker mash, with a greater sparge.

Maybe a thick mash, for conversion of any low eznzyme grains, then diluting for last 20 minutes (mashout) should give the highest efficiency.


Also wondering if the eficiency, of all-in-one systems, that have several litres of static/unused/deadspace 'jacket water' (sitting between the maltpipe and outer wall), might be improved by forcing circulation of this unused water. Maybe by occasionally sticking the recirculation hose down one of the pipe lift holes - and perhaps for just the last 20min.
This unused water (not mixed in till the malt pipe lifted), doesn't seem to be factored in (brewfather water/grain ratio). It's around 4l with my average batch size of 23l (in BZ35 g4).

 

[dmtaylor]

These are great questions.

My belief is that if the total water volume stays equal, then the water:grain ratio and thus mash:sparge ratio does not matter, and you should end up with about the same efficiency either way.

Where the thick mash has its advantage is if you also sparge extra and boil longer to achieve the same final volume of wort. The more sparge you can collect and the longer you can boil, the more sugars you can collect and concentrate in the boil. This can have a very significant impact on efficiency. Similarly, reducing the preboil volume and shortening the boil would have the opposite effect.

Today's highly modified malts mean that conversion happens faster now than historically. The impact may be slight, however, beyond a longer mash time of somewhere between 60 & 90 minutes, where just about any mash that does not have a significant amount of adjuncts can be expected to be nearly fully converted regardless of enzymatic content. Adjuncts or more darkly roasted base malts (such as dark Munich) can take longer to convert but maybe not as much as we might imagine.

Interesting that you mention 20 minute mashout. My own theory with step mashes is that the specific temperatures and times at each step do not matter nearly as much as the total mash time. I believe we can usually safely ignore the exact temperatures of each step and simply add up all the times, and if we mash within a Goldilocks zone of reasonable mash temperatures (say 64-73C), then all that really matters is the total time spent in that range. Time spent at 75-76C at the end of the mash can be included in the total mash time since the enzymes have already done the bulk of the work prior, while much of the alpha still remains. But I doubt there is magic at the mashout temperature of 75C or so -- it is simply alpha that is acting at relative warp speed at that temperature whilst also being denatured at a high rate. Extending the mash an extra 10-20 minutes at some lesser temperature of say 70-72C is probably going to have about the same effect, and a wee bit of the beta amylase *might* even still be around for the ride but don't quote me on that, but if I'm right, the beta is working at warp speed right before it denatures at whatever that magic temperature point is for the beta.

I'm not sure what you mean about jacket water. If added to the mash, it will increase the sparge and boil volumes, and would have similar effect to what I mentioned above about collecting and concentrating extra sugars. If not added to the mash, I doubt it would affect anything at all whatsoever.

 

[foxy]

Just wondering if a thin mash, with smaller sparge, or a thick mash with larger sparge, should give greater mash efficiency (where final total water volume is the same).
If the ideal water:grain ratio, depends on diastatic power, how do you calculate it for a mix of grains?

During mash, sugar concentration in the saturated grain, will gradually equalise with that in the wort, so a thin mash with more dilute wort, should extract more of any sugars present.
A greater sparge volume, would wash off a higher proportion of the residual (surface) sugars.
But I can't imagine that sparging, even if done slowly, would remove much more sugar from within the grain.

It's said, that a thicker mash can be more efficient (or faster), due to the higher concentration of enzymes. With todays highly modified malts, is that still a factor, or does it only apply when using a high proportion of specialiaty malts or unmalted grain?
And could the enzymes all be washed from malted grain, leaving just starch behind, before there's been time for conversion?

Im guessing, that, given sufficient enzymes, the thin mash would be the more efficient overall. Yet brew software (default settings) often suggest using a thicker mash, with a greater sparge.

Maybe a thick mash, for conversion of any low eznzyme grains, then diluting for last 20 minutes (mashout) should give the highest efficiency.


Also wondering if the eficiency, of all-in-one systems, that have several litres of static/unused/deadspace 'jacket water' (sitting between the maltpipe and outer wall), might be improved by forcing circulation of this unused water. Maybe by occasionally sticking the recirculation hose down one of the pipe lift holes - and perhaps for just the last 20min.
This unused water (not mixed in till the malt pipe lifted), doesn't seem to be factored in (brewfather water/grain ratio). It's around 4l with my average batch size of 23l (in BZ35 g4).

1) A thinner mash will improve yield.
2) Starch is in the grain, not sugar. The enzymes are in the wort once one hydrolyses the grain.
3) Sparging will release more sugars from the grain bed, especially after mash-out temperature. The lower viscosity helps the wort run freely. I don't sparge and get 65% efficiency. Sparge and I could expect a 20% rise on the 65%
4) As above enzymes are released from the grain during mash in but they (Alpha and Beta Amylase) work hard to convert the starch to sugar both fermentable and none fermentable sugar. The crush is what makes the starch available, a too coarse a crush and there will be starch left in the grain.
5) You guessed right the thinner mash in a homebrew situation is far more efficient than a thick mash. It is said that a thicker mash protects the beta-amylase which gives us the fermentable sugars but as long as the temperature is uniform in a homebrew vessel then there is nothing to worry about.
6) If you are talking about none fermentable as low-enzyme grains, don't add them to the hop spider as you have suggested in a previous post. Bung them in at mash-out, they aren't in the grain bill to convert, just to add colour, and unfermentable sugar and flavour.
7) You are worrying too much about the liquor around the malt pipe. Just think about the liquor going through the system as a concentrate and when you lift the malt pipe everything becomes equal

 

[The Baron]

I always use a thinner mash and certainly in the first period of mash when many brewers stir the mash quite a lot this will certainly have more grain contact with the wort and yield a higher amount of sugars.
Stirring is also a factor if you are looking for higher efficiency too

 

[Sadfield]

From Brewing: Science and Practice, Briggs 2004.

Starch extract is lower at mash a ratio less than 2.5, and constant after. Probably, of little impact to most homebrewers, AIO and BIAB being common.

 

[MashBag]

For the little gain it gave, I have up sparge altogether.

 

[LeeH]

Me too, 20% eff extra is not something I’ve seen.

 

[JockyBrewer]

My belief is that if the total water volume stays equal, then the water:grain ratio and thus mash:sparge ratio does not matter, and you should end up with about the same efficiency either way.

If you are fly/continuous sparging where you sprinkle/add water continuously over time then I'd think mash:sparge ratio does have an effect on efficiency. As long as you're getting complete conversion, the more liquor you can then sparge with the better as you're maximising the sugar concentration gradient.

 

[The Baron]

I do sparge but jug sparge so the water is in within 10 minutes, I can not see the reason to fly/continuous sparge for a hour plus for what is probably a couple of extra points which in real terms adds very little extra to the beer taste wise all it does is waste a hour of brew day and probably a lot more money as some of the sparge systems I have seen must cost plenty.
I get nothing less than 75% Eff with my method which is good enough for me and as most homebrew recipes are written to 70-75% Eff I just can not see the reason unless you are chasing numbers or anal.
Ps I am not being rude if that's your bag do it but to what real end

 

[Sadfield]

@The Baron are you using a recirculating AIO?

I think it's all relative to the kit. On a 3 vessel set up a good long sparge will return high efficiency. On the other hand, quickly jugging a few litres over a recirculated mash is a complete waste of time. AIO are essentially sparging as they mash and should return good efficiency.

Getting higher than 75% (or whatever number you feel is adequate) brewhouse efficiency might just be a byproduct of equipment, technique or good practices rather than a desire to achieve a number.

 

[The Baron]

Yes I am Sadfield. You are correct in that a re-circulation AIO will yield good Eff (more than a standard 3 vessel)without a long sparge but a jug sparge is part of the Eff as it rinses the sugars from the grain no matter how short the sparge is so it is not a waste of time.
No jug sparge will result in lower efficiency even in a AIO system just not as much difference as a standard 3 vessel system which will suffer from no re-circuation.
I would not spend over one hour trickling water through the grain bed of a 3 vessel set up but would rather add a little more grain at a slightly higher cost and write the recipe to suit the Eff but even a jug sparge will improve the Eff maybe not as much as a slow rinse.
If you are a aficionado of that method do what suits

 

[Sadfield]

That was all very contradictory. No point in sparging on 3 vessel, make it up with grain and recipe design. Sparging with a jug gets me more efficiency on a self sparging machine. Why not use a bit more grain?

Sparging on a 3 vessel ýields far more than a couple of % efficiency unless you're doing it wrong.

It's very weird that not being wasteful with ingredients is viewed negatively in brewing. The complete opposite to cooking.

 

[The Baron]

I did not say that what I said was what I would rather do and the reason I jug sparge is it takes me a matter of minutes not hours of my time watching a trickle through system. It really is as easy as jugging the water into the AIO and letting it drain. The mash can be lifted from the AIO and placed over a bucket to further drain while setting the AIO to boil any further sparge collected from the bucket can be added to the AIO while it is reaching boiling.
I also pointed out that using a 3 vessel system I would rather add more grain to the recipe than sit over a hour to get a higher EFF and that using a jug sparge which is minutes of time will add some Eff and not a waste of time as you suggested.
No where did I say it was a couple of % in Eff also it is not viewed negatively about using more grain to counter the lack of spending time and money on sparging equipment it is what most BIAB brewers do.
What I was trying to get across is that some brewers will spend 5/10 minutes to rinse through sugars even some BIAB brewers jug or dunk the bag to rinse out sugars as it is not a waste of time and time is more precious for some brewers than sparging for hours to get more Eff.
The amount of difference in Eff is reduced with a standard 3 vessel system by doing a simple jug rinse so it is not as much difference as doing no sparge at all and the amount of extra grain is not a big expense in the big picture compared to the cost of time spent and the cost of buying a efficient sparge system, you would have to brew many many brews before the extra grain cost is more than a efficient sparge system plus somebody's time which has no real monetary value.
If some brewers want do that as part of their brewday so be it that is want they enjoy but many AG brewers have busy lives and may not have the time to extend their brewday by 1 to 2 hours not to mention the issue of over-sparging and tannin extraction etc unless you want to take PH and further gravity readings to prevent this again further time to the brewday.
I will say if you want to or have the time to do the long sparge process do it but that is where the anality of chasing Eff may start which then overtakes the process of brewing beer and enjoying the brewday
Ps sorry to the OP as I think we may have diverted away from the original question
.

 

[Sadfield]

It really is as easy as jugging the water into the AIO and letting it drain. The mash can be lifted from the AIO and placed over a bucket to further drain while setting the AIO to boil any further sparge collected from the bucket can be added to the AIO while it is reaching boiling.

Turning an AIO into a two vessel system for a few extra percent efficency. A bit anal.

Anyhow, let's get back to thread about chasing efficiency. Which mash thickness is best?


Similar recipes.

3 Vessel - 3.27l/Kg - 82.8% Mash Efficiency - Fly Sparged.

AIO - 7.03l/kg - 80.7% Mash Efficiency - No Sparge.

If you run your system properly, @dmtaylor point correlating total water and efficiency holds true in my experience.

 

[jambop]

Turning an AIO into a two vessel system for a few extra percent efficency. A bit anal.

Anyhow, let's get back to thread about chasing efficiency. Which mash thickness is best?


Similar recipes.

3 Vessel - 3.27l/Kg - 82.8% Mash Efficiency - Fly Sparged.

AIO - 7.03l/kg - 80.7% Mash Efficiency - No Sparge.

If you run your system properly, @dmtaylor point correlating total water and efficiency holds true in my experience.

So using an all in one system what would be your suggested grain to liquor ratio be ? I use a 1kg to 2.7 L ratio but still require to sparge with quite a large volume of liquor to reach the preboil volume specified by most brew calculators. I find sparging only takes me about 20 mins for say a 15L sparge volume . Could I just do a full volume mash and still get a good conversion and do no sparging ? Seams like a big ask. For example if I do a standard mash I would mash with about 21 L of liquor if I go full volume I would use 35 L . I don't think I would want to boil for less than 60 mins and normally boil for 90 mins .
one other thing I only crush my grain at about 1.4 mm which greatly helps with recirculation not sure how this ties in with greater mashing ratio. Could be a very interesting experiment but the Scotsman/ scientist in me says there are sugars to be harvested there in those mashed grains
edit
sorry I see you say about 1kg/7 L so that is more than double my normal ratio .

 

[MashBag]

I am recirculating all the time, so I really think sparge is pointless. I boil for 45mins

 

[Sadfield]

I'd stick with what you are doing. At 2.7l per Kg, you can't really go any thicker (lowering mash in and increasing sparge volume) without hitting extract issues as shown in the graph earlier. 2.7 is what Grainfather suggest as the most efficient for their systems.

What mash and brewhouse efficiency figures are you getting?

As general observation, needing some form of sparge water vessel does appear as a failure of principal, of systems that claim to be All In One.

 

[peterpiper]

From Brewing: Science and Practice, Briggs 2004.

View attachment 94556
Starch extract is lower at mash a ratio less than 2.5, and constant after. Probably, of little impact to most homebrewers, AIO and BIAB being common.

 

[peterpiper]

Good graph, interesting that extract falls off at the thicker end, but not at the thinner.
Did Briggs say what mash time was used?

Maybe a graph, of extract vs time for the different starches, is needed.

G. Wheeler suggests the water range can be 1.5-3.5 L/kg, but 2 - 2.5L/kg is normal.
I've been trying brewfather, but not sure why it's default water ratio should vary between equipment. For BZ_35l_gen4 3.2l/kg; BZ3.1.1_35l 3L/kg; grainfather_G30 2.7L/kg.

I tend to go with around 3.5L/kg, or 2L/kg at start of multi-step mashes. So happy now to stick around that.

With my typical 5 - 6kg grain bill, my system couldn't fit 7L/kg.

Thanks for everyone else's suggestions, I'll not try replying to all.
Main aim is an enjoyable brew day, so thinner mash and a fairly quick sparge suits me.


Temperature and denaturing time is interesting. Now having a BZ35_g4, and working from the Bluetooth probe thermometer, I'm seeing just how far the grain bed temperature is below/behind that reported from the inbuilt sensor (so ends up mash now taking much longer): I don't like stirring too much after dough in, so top of grain always starts cooler, as well as cooling more during initial grain bed rest (before recirculation). And any temperature step, done by the heater rather, than a hot addition, takes ages.

Brews prior to BT probe, always came out fine, correct OG, but often ended at SG below target. But I've had a couple recently (OG still correct) but maybe too high in dextrins (taste & final gravity ending on high side). So I'm beginning to wonder if mashing at accurate 'correct' temperatures is actually too hot.

 

[foxy]

I do sparge but jug sparge so the water is in within 10 minutes, I can not see the reason to fly/continuous sparge for a hour plus for what is probably a couple of extra points which in real terms adds very little extra to the beer taste wise all it does is waste a hour of brew day and probably a lot more money as some of the sparge systems I have seen must cost plenty.
I get nothing less than 75% Eff with my method which is good enough for me and as most homebrew recipes are written to 70-75% Eff I just can not see the reason unless you are chasing numbers or anal.
Ps I am not being rude if that's your bag do it but to what real end

The main reason Baron for a slow gentle sparge is to prevent channeling and to prevent washing tannins into the wort.

From Brewing: Science and Practice, Briggs 2004.

View attachment 94556
Starch extract is lower at mash a ratio less than 2.5, and constant after. Probably, of little impact to most homebrewers, AIO and BIAB being common.

Totally irrelevant in the homebrew scenario. Commercial brewers keep the mash temperature uniform, throughout the mash, and the grain bed.

@The Baron are you using a recirculating AIO?

. AIO are essentially sparging as they mash and should return good efficiency.

AIO is not in any way shape or form sparging, more of a vorlauf. Depositing debris from the mash onto the top of the grain bed.

AIO - 7.03l/kg - 80.7% Mash Efficiency - No Sparge.

Whoever told you that is pulling your chain. BIAB will, but the AIO's are limited by crush