Full Volume Efficiency Questions

[#brewlife]

Hi All,

Recently thought id try my hand at full volume brewing as something to try and as a way to save time by cutting out the sparge all together.

Ive read lots of old threads online of people saying they're getting 75%+ efficiency and im just trying to figure out how this works in a full volume, no sparge environment.

I have been using formulas or tables on braukaiser to estimate my first runnings for ages so in know when conversion is complete and i can start sarging, and its usually spot on +/- a point or 2.
http://braukaiser.com/wiki/index.php/Understanding_Efficiency

In beersmith when i set my BH efficiency to 70% it predicts a preboil gravity of 1.051 for a simple grain bill at 6l/kg. However the sg based on 100% conversion efficiency from braukaiser is 1.046 at 6l/kg. How can these be different?

When i brewed this, i mashed at 64 for 60min and the gravity of the mash was 1.044, then mashed out to 76 for 10min drained to the kettle and the first runnings were 1.046. if i tweak beersmith BH efficiency till i get 1.046 it shows 63%.

So essentially im wondering how people get higher efficiency on full volume no sparge brewing when they are essentially limited to the conversion efficiency of the grain (effectively the sg of the first runnings being the pre boil gravity). Your OG will be what it will be based on boil off rate and volume

 

[wide eyed and legless]

I set my efficiency to 60% which is what I get or close to, on other forums I have read of 80% efficiency, I also don't see how it can be possible. Either the efficiency is not being calculated correctly or someones having a lend.

 

[#brewlife]

There is a lot of bad information around I agree.

and to make it worse every book has a different definition of efficiency.
I will continue to play with this full volume mash and see what happens but I don’t see the numbers jumping considerably as I can usually get 100% conversion in the mash.

 

[razz]

Hi BL. I started doing no sparge on my braumeister a while back and I got a drop in efficiency. I started stirring the mash 2-3 times during the main rest, that helped my efficiency get back up.

 

[MHB]

Going to depend on where you start, there are two schools of thought that give different answers: -
Efficiency is expressed as a percentage of the mass of malt used.
if we mashed 1kg of malt and got 4.5L of sweet wort with a gravity of 1.040 (10oP) we would have (as Plato (oP) is %WW sugar equivalent in solution), 4.5L at 1.040 would have a mass (weigh) 5.616kg, that wort would be 10% solids so, 5.616*0.10 = 0.5616kg or 56.16% of the 1kg of malt.
Efficiency is expressed as a percentage of the potential of malt used.
If we looked at the specks of the malt and worked out that the CGAI (coarse grind as is) potential of the malt was 74% "available" the rest being unsmashable bits, water (3-5%), silicates... we could say we have a potential of 0.74kg of solids. given the same recovery as above we would have recovered 0.5616 out of 0.74kg so 75.9% of the potential.

Different answers, same outcome and both equally valid, just depends on your starting assumptions. German books often use the % of grist, most other people use % of potential.

There is a handy little equation that I use
oP first running's = Potential/(L:G+Potential)
Using your L:G of 6:1 and the potential of 0.74, remembering that about 1L/kg of water will stay in the grist while about 5L is recovered, you would expect in the kettle
oP = 0.74/(6+0.74), = 0.1095 (remember Plato is percent WW) so expect around 5L @ 10.95oP or from SG=(4*oP)/1000+1 an OG of 1.0438 (meh 1.044)
I find this works every time on my system where I know exactly what I'm doing, if that helps.

Mark

 

[mongey]

I do full volume and it never made sense to me until I changed my settings to kettle ending efficiency rather than Brewhouse.

I get 75 %pretty regularly but again that is including my losses in the kettle. So my BH is lower.

I think allot of people boost their numbers in recipes. Why you would bother I’m not sure.

 

[MHB]

mongey
75% measured into the fermenter is actually pretty good! The term used is Overall Efficiency, as it includes all your losses.
Brewhouse Efficiency is used to refer to the amount of extract in the kettle (before or after the boil it should be the same - unless you have a boil over)

razz
If you are having to stir the grist in a Baumeister I suspect your milling is too fine. Any continuous recirculating system needs a fairly coarsely crushed, free flowing grain bed to work properly, might be worth playing around with your mill settings.

Mark

 

[#brewlife]

Going to depend on where you start, there are two schools of thought that give different answers: -
Efficiency is expressed as a percentage of the mass of malt used.
if we mashed 1kg of malt and got 4.5L of sweet wort with a gravity of 1.040 (10oP) we would have (as Plato (oP) is %WW sugar equivalent in solution), 4.5L at 1.040 would have a mass (weigh) 5.616kg, that wort would be 10% solids so, 5.616*0.10 = 0.5616kg or 56.16% of the 1kg of malt.
Efficiency is expressed as a percentage of the potential of malt used.
If we looked at the specks of the malt and worked out that the CGAI (coarse grind as is) potential of the malt was 74% "available" the rest being unsmashable bits, water (3-5%), silicates... we could say we have a potential of 0.74kg of solids. given the same recovery as above we would have recovered 0.5616 out of 0.74kg so 75.9% of the potential.

Different answers, same outcome and both equally valid, just depends on your starting assumptions. German books often use the % of grist, most other people use % of potential.

There is a handy little equation that I use
oP first running's = Potential/(L:G+Potential)
Using your L:G of 6:1 and the potential of 0.74, remembering that about 1L/kg of water will stay in the grist while about 5L is recovered, you would expect in the kettle
oP = 0.74/(6+0.74), = 0.1095 (remember Plato is percent WW) so expect around 5L @ 10.95oP or from SG=(4*oP)/1000+1 an OG of 1.0438 (meh 1.044)
I find this works every time on my system where I know exactly what I'm doing, if that helps.

Mark

Thanks for the replies gents,

I built my setup as a 4V HERMS so i did go the recirculating route. Turns out from my recent googling it was more of a K-HERMS as i had the volume split over the HLT/BK and MT, recirculating through the HEX. Both HLT/BK and MT are converted keggles. Essentially did a vorlof first to set the bed then recirculated, I didn't want to stir as i was worried about grain getting into the HLT/BK but did cut the top of the bed a couple of times.

Mark, this formula for firs runnings is what i use also, though i had assumed 80% potential and i rounded up to 6L/kg from 5.96L/kg:
=259/(259-(0.8/(5.96+0.8)*100))
=1.044

Pretty much spot on every time, occasionally it wont fully convert 100% at lower mash temps but a mash out will get it there there will just be more body in the finished wort. Ive just always found that it worked and used it to time my mash over the iodine test. Can i ask how you got the 5.616kg in the above example?

Mongey,

Setting the trub loss to 0 in BS, kettle end efficiency now makes sense. Sitting at 65% BH and see the first runnings at 1.044. I dont see how it can be higher than this unless your getting over 80% out of the grain potential.

Cheers,

 

[MHB]

As oP is %WW, you need the mass of wort, not the volume, mass is Volume * Density the numbers I uses were just a "what if" 4.5L*1.1040 = 4.68kg, 5.616 just proves I can be a fat fingered fumble bum sometimes to!

 

[mongey]

Thanks for the replies gents,

IMongey,

Setting the trub loss to 0 in BS, kettle end efficiency now makes sense. Sitting at 65% BH and see the first runnings at 1.044. I dont see how it can be higher than this unless your getting over 80% out of the grain potential.

Cheers,

I did some tinkering with the numbers from my last 3 brews looking at my BH and 2 were 63% and one 64% So pretty much on par with what you are getting.

 

[Cian Doyle]

I tried 65% and it has never quite cut it, probably differences in grain crush an systems.

 

[Coalminer]

Grain crush is very important

 

[mongey]

I tried 65% and it has never quite cut it, probably differences in grain crush an systems.

I just do single vessel biab and a while ago ago I started asking my home brew shop to run the grains through the milll twice.

it hasn’t made a massive difference but I think my numbers have been a bit better since. More consistent

 

[Reg Holt]

I have the Guten and have been doing no sparge, the loss of efficiency is taken up by the addition of more grain. I would tend to go along with WEAL, if someone says they get the same efficiency without the addition of extra grain they are telling porkies.

 

[MHB]

Efficiency is about the amount of extract you get from the malt compared to the amount available, expresses as a percentage.
Here is a snip from an old Weyermann COA, full document at end.

We can see the potential is 81.1% that is the FGDB (fine grind dry basis) fine grind is 0.2mm, so way finer than we or even a commercial brewer would use.
The moisture content is given as 4.5% and there is one other factor to take into account. The Coarse/Fine difference, the difference between a sample crushed at 0.2mm and 0.7mm and subjected to the Congress Mash (a world wide agreed standard test)
What is left is called the CGAI (coarse grind as is) potential.
Take the FGDB (81.1) subtract the moisture content (4.5) leaves 76.6%. There is still the C/F difference to take into account, generally it is less than 2% for a well modified malt, less than 1% can indicate problems with the malt, lets call it 1%, so the CGAI would be 75.6%.

If you mashed 1kg of the above malt and got 756g of extract (it doesn't matter how much water that is dissolved in) you would have achieved 100% Efficiency! It isn't going to happen.

Lets say we want to make reasonably strong beer and at full volume no sparge...mash at 6:1
The amount of water retained by the grist is between 0.65 and 0.8L/kg, depending on the fineness of the grind. lets call it 0.7 for this case.

Using the standard equation to determine first running's (in this case all the running's)
oP Wort = 0.7569/(6+0.7569) = 0.7569/6.7569 = 0.112, or 11.2oP
We put in 6L/kg and got back 5.3L at 11.2oP or an SG of 1.0448 (I doubled checked this time)
The mass of wort recovered is 5.3*1.0448 = 5.53744‬kg
At 11.2oP we have 5.53744*0.112 = 0.620kg of extract (solids)
The malt had a potential of 0.756kg so we recovered 0.620/0.756 = 0.82 or 82%, the rest is still in the grist and you need to sparge to get more of it out.

Having a quick play with the L:G (it takes ~2:1) to cover the grist in water. Is pretty clear that the more water you use the more efficient your extraction is. Naturally we pretty quickly run into the problem of having a very thin wort and needing to boil for a long time to get back to the OG we are looking for.

Pretty easy to rearrange the equation so you can predict what L:G you need to hit a target OG.

Interesting that back in the old days before sparging brewers made three beers from a grain bill. The first being a Strong Beer, then the grain bed was refilled with hot water, allowed to rest, drained to give Table Beer, and again to give Small Beer. Overall Efficiency would have been pretty high.

Full Volume mashing can be very easy, there is going to be a cost in efficiency but if you wanted to do a Party Gyle that can be mostly recovered. If you wanted to make a low ABV Farm House Saison or the like it would be the way to go.
100% extraction/efficiency is never going to happen.
Mark

 

[#brewlife]

Great answer Mark. Thanks for taking the time to educate.