brewtarget-devs team mailing list archive

[Ben Werbowyj <ben.werbowyj@xxxxxxxxx>]

Speaking as a user of software tools and estimators - it's the mash/lauter
efficiency that interests me most in the recipe formulation and on brewday,
as it's the one that tends to be variable depending on the recipe. For
example if you are packing your mash tun full to make a big beer then you
tend to lose numbers in the mash/lauter process when compared to a lower
gravity beer (system dependent of course).

I certainly agree that just about everyone has their own boundaries that
they determine their efficiency within, and by defining separate
mash/lauter (or to the kettle) and brewhouse (or to the fermenter) we can
cover just about all the bases. The only other step would be out of the
fermenter (or to the package), but for most homebrewers and hobbyists this
isn't really a big concern.

Ben


On 10 March 2013 04:01, Philip Lee <rocketman768@xxxxxxxxx> wrote:

> Welcome Tim!
>
> You are right about the can of worms. Storing multiple efficiency numbers
> definitely sounds like a good idea to me, and adjusting loss/efficiency
> numbers for recipe ingredients could be interesting.
>
>
> On Fri, Mar 8, 2013 at 3:21 PM, Tim Payne <swstim@xxxxxxxxx> wrote:
>
>> Efficiency is indeed a can of worms.  BeerSmith picks the nit by
>> reporting two efficiencies - mash efficiency (conversion + lauter or
>> to-the-kettle) and total brewhouse efficiency (to-the-fermentor).  But as
>> you mention BeerXML uses "total brewhouse efficiency" in the
>> recipe/equipment definitions.  I think the typical way of calculating here
>> is all fundamentally flawed - efficiency is a function of both the
>> equipment and the recipe; trub loss can be significantly higher with a high
>> hop load if you filter before the fermentor (needed with plate chillers) or
>> use leaf hops.  Also lauter efficiency varies with OG and sparge method.
>> This is a hot button issue for me and it's one of the top items on my
>> personal todo list to try to rectify, or at least decouple the issues
>> somehow.
>>
>> Just off the top of my head I propose adding equipment parameters for
>> "mash efficiency", "vol loss per pellet hop oz/g", "vol loss per leaf
>> oz/g", and maybe "mash efficiency loss per OG point".  Existing trub loss
>> would be a constant across recipes and would be chiller/deadspace/break
>> loss.  Zeroing the loss fields would keep things the same for the folks who
>> don't filter anything or just don't care.  I will add a blueprint for this
>> soon.
>>
>> Adding more confusion is that definition of "brewhouse efficiency" varies
>> depending on who you talk to.  There's a bit of discussion here:
>> http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency and
>> there's lots more if you search homebrewtalk.  So, I like to use "total
>> brewhouse efficiency" to clarify when possible.
>>
>> Tim
>>
>> PS Hey all, another new guy here.
>>
>> On Fri, Mar 8, 2013 at 8:43 AM, Philip Lee <rocketman768@xxxxxxxxx>wrote:
>>
>>>
>>>
>>> On Thu, Mar 7, 2013 at 9:12 PM, mik firestone <mikfire@xxxxxxxxx> wrote:
>>>
>>>> In a small word, the brewnote efficiency calculations are rather messed
>>>> up. I'm using the postboil gravity when I should be dealing with the
>>>> preboil. I'm trying to unwind this right now but I keep running into weird
>>>> things.
>>>>
>>>> I am specifically looking at Recipe::recalcBoilGrav() and trying to
>>>> figure out why the boil gravity (aka, SG) is worried about trub/chiller
>>>> losses. Trub/chiller loss shouldn't have anything to do with the preboil
>>>> gravity, should it?
>>>>
>>>
>>> You'd think it wouldn't have anything to do with it. However, there is a
>>> nit to be picked...
>>>
>>> BeerXML says the recipe efficiency is brewhouse efficiency, which is
>>> "to-the-fermentor" efficiency. Meaning, if I have 5.00 kg grain with 76%
>>> yield (3.80 kg sugar), and my brewhouse efficiency is 70%, I get 5.00 kg *
>>> 0.76 * 0.70 = 2.66 kg into the fermentor. Now, how would you go about
>>> finding how much sugar is in the kettle? Since the recipe's efficiency is
>>> "to-the-fermentor", we can't use that number directly; we need
>>> "to-the-kettle" efficiency. Since you are always losing some amount of
>>> sugar at each step of the brewing process, it must be the case the your
>>> "to-the-kettle" efficiency is somewhat higher than your "to-the-fermentor"
>>> efficiency. How much more?
>>>
>>> eff_tokettle = eff_tofermentor / (1 - trubChillerLoss/finalVolume)
>>>
>>> To extend the previous example, suppose my final volume is 20 L and I
>>> lose 1 L in the transfer from kettle to fermentor.
>>> eff_tofermentor = 0.70
>>> trubChillerLoss = 1 L
>>> finalVolume = 20 L
>>>
>>> sugar_kettle = 2.66 kg / (1 - 1L/20L) = 2.80 kg (73.7% efficiency to
>>> kettle)
>>> sugar_lost = 1L/20L * 2.80 kg = 0.14 kg
>>> sugar_fermentor = 2.80 kg - 0.14 kg = 2.66 kg (70.0% efficiency to
>>> fermentor)
>>>
>>> I highly doubt any other software is picking this nit, but it definitely
>>> exists. You can see for this typical example that all your OG-related
>>> numbers would be off by about 4% if you don't calculate the kettle
>>> efficiency to be different from the brewhouse efficiency.
>>>
>>> --
>>> Philip G. Lee
>>> rocketman768@xxxxxxxxx
>>>
>>> --
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>>>
>>>
>>
>> --
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>>
>
>
> --
> Philip G. Lee
> rocketman768@xxxxxxxxx
>
> --
> Mailing list: https://launchpad.net/~brewtarget-devs
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>