Brewing Classic Styles Efficiency and DBFG Questions

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jmichalicek

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I've been revisiting some of the details in my books... things I've just glossed over, accepted as "this is weird but its working for me", etc. to see if anything clicks for me which didn't when I first started brewing. One thing I noticed is that my recipes from Brewing Classic Styles come out with a lower (sometimes MUCH lower) OG in software such as Brewtarget (which I'm close to abandoning anyway) and Brewfather.

In the book Jamil states that the recipes target 6 gallons into the fermenter with a 70% efficiency and extract based on the maximum dry basis fine grind for grains. I have to assume efficiency is mash efficiency and not brewhouse efficiency. What I have noticed is that in every spec sheet I have looked at only the minimum dbfg extract, or in one case (I already forgot who) they said it was something along the lines of "average brewers actually see", rather than the maximum. I'm wondering if this is what is throwing things off or if I'm just still misunderstanding something.
 

hottpeper13

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You're looking at the fine grind dry basis and that's what is used for a congress mash and gives the potential of the malt. Brewers use the course grind as is to figure out what they can expect for gravity units per pound.
 

hotbeer

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You adjust the efficiency value in Brewtarget and other beer software to match what you are actually getting.

If the number is too low for you then you have to figure out where to improve your mash process and other things.

I'm getting over 90% efficiency. I don't think the efficiency value listed with the recipe is intended to match any of the brewing efficiencies that many calculate. It's there mostly just to allow you to match what your typical actual OG obtained is with the recipe.
 
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jmichalicek

jmichalicek

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I think you're misunderstanding. This is not about my real world results. When I plug the numbers from the book into an app such a Brewtarget, Brewfather, etc. with the correct target final volume, specified mash efficiency, etc. the OG the apps say should be expected is always lower than what the book specifies. Sometimes fairly significantly, such as being an entire .010 under - 1.055 as opposed to 1.065, etc.

That suggests to me that either the 70% efficiency is something else or the potential extract the book is assuming to get 70% of is higher than what these apps have in, which has been within 1% of official spec sheets whenever I have looked.

The coarse grind vs fine grind may be it. The book specifies using maximum extract fine grind dry basis. If the "extract % dry basis" shown for example on Finest Pale Ale Maris Otter - Simpsons Malt on the ASBC and EBC tabs is coarse grind that would reduce calculated numbers slightly, but based on Understanding Malt Spec Sheets - Brew Your Own, it should not be much difference
 

kevin58

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I think you're misunderstanding. This is not about my real world results. When I plug the numbers from the book into an app such a Brewtarget, Brewfather, etc. with the correct target final volume, specified mash efficiency, etc. the OG the apps say should be expected is always lower than what the book specifies. Sometimes fairly significantly, such as being an entire .010 under - 1.055 as opposed to 1.065, etc.

That suggests to me that either the 70% efficiency is something else or the potential extract the book is assuming to get 70% of is higher than what these apps have in, which has been within 1% of official spec sheets whenever I have looked.

The coarse grind vs fine grind may be it. The book specifies using maximum extract fine grind dry basis. If the "extract % dry basis" shown for example on Finest Pale Ale Maris Otter - Simpsons Malt on the ASBC and EBC tabs is coarse grind that would reduce calculated numbers slightly, but based on Understanding Malt Spec Sheets - Brew Your Own, it should not be much difference
Forget the final target volume and focus on the efficiency. The 70% figure is what Jamil gets on his system. Your software is set to a certain equipment profile that assumes a certain efficiency. You need to make the adjustments to your software to match what the recipes is getting. More importantly that equipment profile in the software has to match your real world results.
 
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jmichalicek

jmichalicek

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Right, but in software if I (made up numbers here) plug in 13 lbs pale ale malt with a DBFG of 81%, 70% mash efficiency, and a 6 gallon target volume then should that should always show the same OG every time.

The book says "The malt yields are based on 70 percent efficiency of the maximum yield. The maximum yield is the fine grind, dry-basis number for total soluble extract on the malt analysis sheet" and "All recipes are designed to leave 6 gallons of wort in the kettle after boil". So on paper, the same weight of grains should result in the same OG.

This isn't about my efficiency being higher or lower than his when actually brewing. This is a specified efficiency, amount of grains, and end volume. That should always be the same gravity on paper. Now I assume the OGs in this book are really for the malt extract versions, but the book's own substitutions for all grain should be way closer.

I'm not trying to argue with you guys about process. If my process has lower efficiency then yes, I just need to adjust for that. But the math for same grain + same efficiency + same volume should always be the same. So some number I've got is not the same as the book's. In the end, every recipe I've ever made from the book has been great, so they work, but I'd love to understand which number in the book means something different than anything I've got available.
 

hotbeer

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Might be the database for the fermentable stuff has different values associated with the specified malts. I noticed that in Brewtarget the info about the yeast I use is way off from what the website for those yeast say and what I actually get.

Brewtarget is not maintained AFAIK and very likely all the database info is subject to errors for what malts actually give today.

If you know the analysis of the malts and stuff you use in your recipe then change them in Brewtarget to match. But then again you really don't know what your recipes creator was using and whether any of their database info was correct either.

That's part of why you have to just go with the flow. And accept your first tries at different recipes might be.... different.

That's why, TMK, they give you all the flexibility in beer software to change things to let you match your results and for the changing analysis of malts of different harvests.
 
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Bobby_M

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The extract figures for any given malt/malster varies from lot to lot so the only way to 100% nail the numbers every time is to update the extract potential in whatever software you use. I'm not that anal about it so I don't do it, but that's what it would take.
 

doug293cz

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Bobby, isn't that what a congress mash is for?
Yes, the Congress mash is the test that Maltsters use to determine both the DBFG and DBCG grain potentials. You could do one yourself, if you can't get the data for grain you have. There is a modified procedure that is even easier than the ASBC method.

Brew on :mug:
 

hotbeer

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In Brewtarget, each of the malts in its data base has a "yield" listed as a percentage. And it is a editable field.

You could look at your malts analysis and decided if you need to adjust it. For the malts I buy, they have a value for fine crush and coarse crush.

But likely if your aren't getting near the OG of the recipe, then something about your processes are drastically different than the recipe creators.
 

VikeMan

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Ya know, this discussion could be more fruitful with actual examples and actual numbers. OP, why not pick your simplest example from the book and post the specs, along with what your software is telling you for that recipe.
 
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jmichalicek

jmichalicek

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Hey, sorry for the delays. I felt like people might think I was just being an *******, so rather than risk angering everyone I just stepped back for a bit.

Wrote a bunch of stuff up here, ran through calcs several times, etc. I think I found it. Brewtarget is being weird. It appears sometimes it is not calculating the pre-boil volume correctly, and if you force it, it's still getting confused and so that is throwing off numbers. Interestingly, I found Brewfather to have the same issue with the same recipe. Both were calculating way too high initial boil volume and then the rest of the numbers were based off of that volume combined with boil off rate rather than the specified ending volume.

Very weird, but glad I've (sort of) figured it out. It's not consistent from recipe to recipe... some calculate correctly, some are off by as much as 9 points due to both pieces of software deciding I'm going to start with 0.5 gallons or so more water than I should.

So in the cases where it's high, I specify 1.050 gallon/hr boil off rate, but it still starts me at 7.5+ gallons of water. Some recipes start me at just over 7 gallons, as expected with all of the same settings and automatic calculations in place.
 

VikeMan

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So in the cases where it's high, I specify 1.050 gallon/hr boil off rate, but it still starts me at 7.5+ gallons of water. Some recipes start me at just over 7 gallons, as expected with all of the same settings and automatic calculations in place.

Are you talking about pre-boil volume or about total water volume? They are (should be) different.

Wrote a bunch of stuff up here, ran through calcs several times, etc. I think I found it. Brewtarget is being weird. It appears sometimes it is not calculating the pre-boil volume correctly, and if you force it, it's still getting confused and so that is throwing off numbers. Interestingly, I found Brewfather to have the same issue with the same recipe. Both were calculating way too high initial boil volume and then the rest of the numbers were based off of that volume combined with boil off rate rather than the specified ending volume.

So, two different softwares are giving you the same wrong answer? Hmm...

Ya know, this discussion could be more fruitful with actual examples and actual numbers. OP, why not pick your simplest example from the book and post the specs, along with what your software is telling you for that recipe.
 
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