Brau Kaiser Batch Sparge Calculator - Efficiency

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Douglefish

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Alright, so I'm sure that I'm mixing up some terminology somewhere, but hopefully someone can help me out. I plugged in the following to Kaiser's spreadsheet. I'm calculating efficiency for a single batch sparge, and assuming that i get 15% boil off the spreadsheet says that I should have 1.045 wort when I'm done and that would be 84.6% efficiency for 1st and 2nd runnoff (1.038.6 before boil).

------------------------------------------------
11.5 gallon recipe - 1.3 gal/hr boil off - 90 min boil
------------------------------------------------
grain weight 21.2 lbs
extract potential 80%
moisture content 4%
mash water 8 gal
conversion efficiency 97%

grain absorption (apparent) 0.12 gal/lb
dead spaces 0

Sparge Water 8 gal
--------------------------------------

I then plug the same recipe in iBrewMaster and set it up for 80% efficiency and it says that my gravity comes out to be 1.052 with a pre-boil gravity of 1.045.

Obviously the efficiency numbers aren't calculated the same, what am I missing?
 
At a guess, I would say that iBrewMaster is calculating efficiency on the basis of something like as-is coarse-grind (AICG, i.e. real-world efficiency) and I know for a fact that Kai's calculations assume dry basis fine-grind (DBFG, i.e. laboratory efficiency). The iBM documentation may be able to confirm.
 
I wrote iBrewMaster and also compared this to tastybrew.com's online calculator. What they are doing makes perfect sense, they use the specific gravity/lb measurements of each grain and sum them up. They then take the total gravity points after boil and divide the two for brew house efficiency. I can manually do this and it looks correct.

Kai's spreadsheet takes the total weight of the grain, then figures in the extract potential by %. From this he calculates the weight of the extract, and then figures in conversion efficiency. Finally he calculates sparge/lauter efficiency by how much water he puts in each infusion.

I'm still getting a suggested higher efficiency from the spreadsheet and a lower final gravity?

Anyone else use Kai's batch sparge simulator?
 
I use Kai's simulator and it's always spot on. One thing I notice is that Beersmith and some of the others don't take dead space in the tun into account. Kai's spreadsheet gives you a loss in gravity based on that. The other programs will only tell you to add more top up water due to the dead space, but do not calculate the runnings any different.
 
I don't have dead space in my mash tun, and I don't use it in either my brewing software or Kai's spreadsheet.

TheMan, what do you use for extract potential, moisture content, grain absorption, etc?

If I was doing an 11.5 gallon batch, 8 gallons mash, 8 gallons sparge.

80% extract
97% conversion efficiency
.12 gal/lb absorption

Spreadsheet - How can I get 1.045 OG with 84.5% efficiency?

Manual Calculation -
Assuming it's all 2-row at 1.036 per lb (11.5 gal), that's 766 points total.
That puts 100% efficiency at 1.066
70% would be 1.046, which is still higher than the spreadsheet suggests at 84.5%?
 
I use 100% conversion efficiency, so should you. A 1 hour mash is long enough to convert just about any grainbill 100%. 4% moisture content and .12 gal/lb absorption.
 
extract potential should be whatever you typically get. If you get 80% then you put that. You are only doing two runnings, the sparge simulator is telling you what you will get with exactly what you tell it. You are taking your mash runnings and then doing one sparge, the simulator will be correct. It's never failed me.

The brew programs don't take any of that into account, they kind of assume only one method as far as I see. That's the difference I think you're seeing. Try setting it up for 3 runnings and you might be closer to the programs number.

I only use beersmith, so I don't know about the one you use. But no matter how many sparge rounds I tell beersmith to calculate for, it gives me the same gravity. Kaiser's simulator adjusts for this and has not been wrong in 6 brews.
 
I was understanding that the extract potential is not extract efficiency, but rather the percentage of grain weight that is actually dissolve-able in the mash? So if you set it do 80%, it would be that 80% of the grain's weight could be converted to sugar in theory. This should be determined by the maltster not anything I do right?

Setting up 3 running gives me a bump in efficiency by 3% as you would expect.

I have no doubt that the spreadsheet and brewing software are both right. I'm sure it's either user error or terminology. I still can't wrap my head around how the Kai's spreadsheet is giving me a higher efficiency and lower OG?

extract potential should be whatever you typically get. If you get 80% then you put that. You are only doing two runnings, the sparge simulator is telling you what you will get with exactly what you tell it. You are taking your mash runnings and then doing one sparge, the simulator will be correct. It's never failed me.

The brew programs don't take any of that into account, they kind of assume only one method as far as I see. That's the difference I think you're seeing. Try setting it up for 3 runnings and you might be closer to the programs number.

I only use beersmith, so I don't know about the one you use. But no matter how many sparge rounds I tell beersmith to calculate for, it gives me the same gravity. Kaiser's simulator adjusts for this and has not been wrong in 6 brews.
 
I get what you mean, but where it says extract potential I have been putting I've been putting my brewhouse efficiency...and conversion efficiency I have been putting 100%. If I am doing it wrong then I'll keep doing it because i've been getting near pinpoint accuracy with it lol.
 
Speaking of Kai, anyone know what's up with this? I checked and the domain doesn't expire until next year...


OhWWY.jpg
 
I about mentioned the same thing about his domain.

As far as the issue noted, I actually figured it out. There is a miscalculation in the 1st plus 2nd runoff section. The wort gravity is not correct. However, even if you don't have a 3rd runoff that section appears to be correct.
 
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