Once again...volume calculations completely useless

Discussion in 'Recipe Editor' started by J A, Nov 19, 2021.

  1. J A

    J A Well-Known Member

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    I don't know how anyone ever actually uses the pre, post and fermenter volume calculations in the recipe builder. It's complete nonsense. If I select kettle as target and use a figure that I know to be correct for the post boil and hit calculate, it changes both the pre and post boil numbers. If I use a pre boil volume that I know to be correct it still changes both numbers. In either case neither number stays at the input value and neither is correct based on my system profile.
    It's idiotic and I can't say often enough how frustrated and disappointed I am at what this recipe builder has become. Some aspects of it are a complete time suck and don't yield any useful information. Totally over it.
    Fortunately I have my own spreadsheet that calculates my volumes to a tee based on my system (same exact system values that I use, to no avail, in the BF calculator).
     
  2. Donoroto

    Donoroto Well-Known Member

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    I basically don't. I have difficulty making heads or tails of the numbers it delivers, so I just do what I always do in my Brewzilla 35: Start with 8 gallons, add minerals, drain off 2.25 gallons (for the sparge), mash, sparge and boil for an hour. I seem to end up with my 5.5 gallons into the fermenter, so I'm good.
     
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  3. J A

    J A Well-Known Member

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    Yeah...it's a matter of already knowing what you need to know and ignoring the calculations or using false values to try to trick into working with the correct volumes for other calculations.
    The only time I ever use any of it is to double check some values in my spreadsheet and calculate PH and water additions. Unfortunately, based on the inherent inaccuracy of the system, I doubt that I can really trust those.
     
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  4. Pricelessbrewing

    Pricelessbrewing QA Software Tester
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    #4 Pricelessbrewing, Nov 19, 2021
    Last edited: Nov 19, 2021
    @J A

    Hey J A, I'm trying to reproduce this, and am having some difficulties. There's definitely some issues occurring, but not specifically the ones you're pointing out here.

    Can you point to a specific recipe to dig into?
    The irish red recipe for example where you've changed the postboil volume to a lower amount doesn't line up with the batch size (post boil) and your equipment profile.
    11.52 gallons + 3 gallons = 14.52 gallons, but your post boil in the recipe is 14.13 not 14.52.

    This may be a difference of definition of boil off rate? Some books and software define it as the hot preboil volume to cooled postboil volume but this is difficult to measure and not recommended, it's best practice to compare two volumes at the same volume, so Brewer's Friend always uses standard temp volumes unless otherwise noted (mostly just in brew sessions).



    When target = Kettle, the postboil volume is the batch size and the calc button never changes the batch size. It shouldn't, and still doesn't in my testing (in my account, yours, and in donoroto's). Looking at your irish red recipe, and your equipment profile there's an issue specifically occuring where the boil off loss is being doubled.The intended behavior is that the calc button calculates the expected pre/post boil volumes based on the recipe additions, and the equipment profile. There's definitely room for improvement, and it's at the top of the to-do list.

    There's a large update being worked on with our highest priority to resolve and vastly improve the volumes, mash guidelines and equipment profiles behaviors. These are crucial parts of the recipe builder, and without them being accurate and reliable as you say, it's very frustrating to use. It's my main priority.
     
  5. J A

    J A Well-Known Member

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    I'm sure it's just a matter of finding the exact combination of inputs that will yield something accurate. I did find some inaccuracies in my profile but even then, I couln't get the kettle target calculate function to leave one input the same and calculate the other one. I was working on a stout recipe at the time I was having trouble with it.
    For now I just don't want to bother with it. As I mentioned, I have a spreadsheet that I can count on to do the basic math.
    I should probably just keep my thoughts to myself. :)
     
  6. Pricelessbrewing

    Pricelessbrewing QA Software Tester
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    No, please continue to share it's the only way we can improve via user feedback!

    With kettle target, the only thing that should change via the calc button, and tested just now again, is the preboil volume based on the batch size + your boil off rate from equipment profile (plus hop absorptions, and any volume gained or lost via boil sugar additions).

    With target = fermenter both volume do change working from batch size up to post boil then up to preboil working from the recipe losses via ingredients, and the equipment profile.

    We're definitely aware it's not working perfectly as intended though, so we have some significant changes coming. Once they're ready for more user testing, I'll be sure to include you for review. Hopefully we'll be able to get you off that spreadsheet at that time!
     
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  7. J A

    J A Well-Known Member

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    At least a half dozen times that I tried the kettle target calc button in the stout recipe and making several changes to profile settings, both values changed. I may get a chance to look back at it tomorrow.
    And, I'll definitely be keeping my spreadsheet, thanks very much. :D :D It does the simple job of subtracting volumes in the correct sequence so I know exactly how much water I need at each stage of the mash as soon as I put in the desired batch size. As such, I don't have to guess whether the gravity and ABV calculations are coming from an inaccurate volume so I can count on those too. It's simple and accurate and makes it quick and easy to get proper results. :)
     
  8. Trialben

    Trialben Well-Known Member

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    I target fermentor and usually get within half a liter if not smack on in volume.
    Sucks it's not working for you JA.

    This is what I've done in past is adjust my boil off to hit my final fermenor volume.
    But I've got near 0 dead space losses in my unit single vessel so I feel it's easier to measure these losses if so.
     
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  9. Donoroto

    Donoroto Well-Known Member

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    I'll poke at it soon for a good example.
     
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  10. Pricelessbrewing

    Pricelessbrewing QA Software Tester
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    Thanks!

    Any more datapoints we can gather will make sure the updates we roll out in the near future are addressing all the varied scenarios and known issues.
     
  11. Nosybear

    Nosybear Well-Known Member

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    Throwing my 2 cents in.... The volume calculations (the ones mentioned) are simply wonky. I ignore them and add my own values based on experience in brewing. My beef is with the volumes when scaling recipes: I scaled one last week from five gallons down to 3.5 and brewed it as normal.... And ended up with a gallon too much wort. It wasn't a particular problem for the beer, the recipe had way too much extract, but when I scale, I have to do my water calculations by hand. What I get from the site inevitably works out to too much water when scaling down, not enough when scaling up. I'll attach the recipe I used for reference:

    https://www.brewersfriend.com/homebrew/recipe/view/1216239/schneider-weisse-clone/409993

    I'm using the same equipment profile for 5 gallon and 3.25 gallon batches so that's not an issue. I'm using the same procedure and equipment for both batch sizes.
     
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  12. Donoroto

    Donoroto Well-Known Member

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    A closer look told me I don't understand all the numbers. I am using This Recipe for my examples. I've made it public, but I don't recommend it as it did not come out well.

    My manual calcs based on my equipment profile shows that if I start with 33 quarts (25 mash, 8 sparge) I end up with 19 quarts into the fermenter, from a desired 22 quarts, clearly 3 quarts short. (My calcs are at the end of this post)

    In the recipe editor, my batch size is 5.5 gal (22 qt) at the fermenter. Clicking the Calc button at Boil Size delivers 7.2 gal pre-boil, 6.08 post. I don't understand where these numbers come from, especially the 6.08. 7.2 seems to be coming from an assumption that I'll add sparge water to the mash to hit my mash thickness (next paragraph). (FWIW, I don't concern myself with mash thickness, mostly).

    I look at the quick water requirements when I select 'Print' and the numbers there confuse me even more. Why does this include an addition of 1.78 gallons (Apparently from my sparge water) to the strike water? I also get a warning that my mash tun volume is exceeded. But in practice I mash with 25 qt (6.25 gallons), my losses (except boil off) are 8.675 qt, I add 8 qt at sparge to end up with 24.325 qt in the boil pot pre-boil.

    I agree, I should be adding 3 quarts to the whole system to get my 5.5 gallon batch at the fermenter. And in practice, I am often around 2 quarts short with only 5 gallons. Part of that i think is that my misc. losses are much less than 1 qt (I need to change the equipment profile) and perhaps the rice hulls are not as absorptive as we think. Not sure. So for my next batch I will start with 6.5 gallons in the tun and sparge with 2.5 gallons, and see what happens. I did not change the recipe to reflect this

    My conclusion is: The water calculator is probably pretty close and working as intended, but I don't exactly understand why it is doing some things and where some of the values come from. I am not asking for an explanation - I don't want to waste anyone's time because I have not yet read and digested all the documentation for the recipe editor - but will come back here if there's something in the docs that i just can't wrap my head around.

    Thanks,
    Don



    My Calculations:
    8.25 * 4 = 33 qt
    -4.5 boiloff = 28.5 qt
    - 6.375 grain = 22.125 qt
    - 0.3 hops = 21.825
    - 1 kettle & -1 misc = 19.825 qt
    *.96 shrinkage = 19.032 qt into fermenter
    =4.758 gal into fermenter
     
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  13. Sunfire96

    Sunfire96 Well-Known Member

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    I've also been using my own excel spreadsheet for water calculations. The recipe calculator does not adjust for hitting a target preboil/post boil, it just uses the equipment profile. When I brew a 3 gallon partial mash batch the calculator just assumes a full volume boil and there is no way to override this. At this point I just use the calculator for projected OG, which I could also use an excel spreadsheet for. The water/pH calculator has also been difficult to use lately and I've downloaded Bru'N water to use instead.

    Hate to be a Debby downer here, but it'd be nice if the software was working correctly instead of pushing an app that's only half working :confused:
     
  14. Donoroto

    Donoroto Well-Known Member

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    I'm sure they agree. But bugs do crawl in, we'll get 'em sooner or later.
     
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  15. AHarper

    AHarper Well-Known Member

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    I do my best but haven't looked at the water calcs yet lol.
     
  16. Sunfire96

    Sunfire96 Well-Known Member

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    Alan's here, always fighting the good fight :)
     

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