Beersmith Volume Calculation Question about "Batch Size"

[koopa]

"Batch Size" field question.

What volume do you fill in....
a. The amount that you have at the end of the boil? (while wort is still at boiling temps - post grain absorption loss and boil off evaporation loss)
b. The amount that makes it into the primary fermenter? (post chiller and transfer loss)
c. The amount that makes it into bottles? (post trub removal and transfer loss)

I can think of pros and cons for each. I need to know to properly calculate my efficiency and make future recipes.  My guess is CHOICE B....

[MaltLicker]

I consider the answer to be "B" and there are fields for evaporation and transfer losses in the Equipment Profile. 

It is important that users enter their specific data into these fields, or Garbage In/Garbage Out will occur. 

BeerSmith does not know where you are losing wort on purpose or spilling it.  It calculates everything based on what we tell it. 

So, the top line is the entire amount of wort we make at XXX specific gravity at end of boil.  From that top line, all the adjustments for our system and our process are entered and BeerSmith does the math using our entries.  The end result is Batch Size. 

For example, I make ~5.5 gallons of wort but choose to leave about a gallon in the boiler to have much cleaner wort in the fermenter.  This loss affects my EE% which BeerSmith uses for all this math. 

[jomebrew]

Yea, same as MalkLicker.  B!  I usually do a batch size of 6 gallons and try to get 5.5 in the fermenter.  On my system, if I use 5 or 5.5, I am always off.  You kind of need to know the nuances of your process and system to determine the right batch size for you.

[sbbish]

I do the same as MaltLicker and jomebrew. However, be aware that if you use the built-in Carbonation section on the recipe page, you will need to adjust your Batch Size at bottling time for the amount you are actually bottling/carbonating. Otherwise you will end up over-carbonating.

For example, you may set your Batch Size to 6.00 gallons for brewing and you intend to leave behind .5 gallons of gunk in the boil pot. This means you plan to only collect 5.5 gallons in the carboy.
Then, after fermentation, you leave behind another .5 gallons of trub in the carboy and you collect only 5 gallons in your bottling bucket.
But your Batch Size still says 6.00 gallons.
For a 6.00 gallon batch, the Carbonation (at 2.4) suggests using 5.00 ounces of corn sugar.
But since you really only collected 5.00 gallons in your bottling bucket, you really only want 4.15 ounces of corn sugar.
You'd be over-carbonating if you stuck with the 6.00 gallon Batch Size.
Of course, if you're kegging with forced C02, this doesn't apply.

So Batch Size plays one role while you are brewing and another role when carbonating. Just something to keep in mind.

Scott

[koopa]

Thanks for the initial replies guys and great point ssbsh.  One question though (playing devils advocate):  Maltlicker seems to say that loss shouldn't be factored into effeciency, but why isn't the correct answer A then by that logic?  Why by that logic is it ok to factor in evaportation / grain absorption loss from the mash and boil, but not transfer / trub loss?

I'm still getting a feel for my system but typically I think my volumes have been:  
(I do brew in a bag so all the water is put in at once as strike water)

8 gallons of strike water heated to mash temp
Mash in 13lb grain
Lift out grain bag and let wort drain back into boil kettle
7.25 - 7.5 gallons of wort usually remain after the grain absorption and is then boiled for 60-90 minutes depending on recipe
This usually results in 6 - 6.5 gallons of boiling wort after boil evaporation loss
Then I pump through a plate chiller and into a carboy.
BTW transfer loss through the plate chiller, and volume loss when the liquid is cooled (probably about 5%) I usually end up with btw 5.25 - 5.75g in the primary fermenter
I then usually lose 0.25 - 0.5 gallons to trub loss and transfer from carboy to bottling bucket to bottles resulting in 5  - 5.5g into bottles
 
Based on that, is my "batch size"

7.25 - 7.5 gallons     (post grain absorption loss)
6.00 - 6.5 gallons          (post boil evaporation loss)
5.25 - 5.75 gallons     (post leaving a bit with the most break material in the boiler, chilling the rest, and transferring the chilled wort to primary)
5.0   - 5.5 gallons       (into bottling bucket)
4.75 - 5.25 gallons    (into bottles)

[koopa]

The question really is are we supposed to measure "Mash Conversion Efficiency" or "Brewhouse Efficiency" so to speak? Promash seems to use the former and Beersmith states it does the latter but I think it confuses the two none the less...

I found a thread on the promash forum and the creator of promash says that "batch size" = end of boil volume prior to transferring to a fermenter so on promash transfer loss and trub loss are not factored into efficiency. This makes more sense to me as I thought efficiency was more about starch conversion and less about starting volume vs. bottled volume. In poking around Beersmiths help guide I think I found that Beersmith claims to work the opposite way...

Batch Size - "The finished batch volume - i.e. the amount of beer you hope to brew. Batch size is used in calculating most of the elements in the beer profile."

So that suggests ANSWER C...

Beersmith Help feature has this to say as well:

Brewhouse Efficiency: "It represents the percentage of potential sugars extracted from the grains during the mash process plus accounts for losses during the process such as trub losses."

So that suggests ANSWER C TOO because....

Efficiency isn't solely your mash conversion rate on Beersmith. Beersmith does factor losses into efficiency. Trub loss occurs post primary fermentation, as does transfer losses during bottling. Now that I'm noticing its called "Brewhouse Efficiency" and not "Mash/Conversion Efficiency" it all makes sense. All but one part...why would adjusting your batch volume change your estimated OG then?

OG is a concentration of sugar in the water so loss of overall volume does not change concentration. While I understand why such losses factor into the concept of "Brewhouse Efficiency" they shouldn't play a role in the estimated OG in my opinion.  The OG of your beer is the same post boil, post transfer losses to the primary via the chiller, post transfer losses from fermenter to bottling bucket and to bottles.  So why should the expected OG change when I change such loss factors by changing the "Batch Size" on Beersmith then?

I use brew in a bag with no sparge so I don't top things off with water to get volumes where I want them...I have to work it all out in advance and add the correct amount of strike water all in one shot and balance it with my estimated Mash Conversion Efficiency to hit my target gravity marks. So I need to accurately be able to measure my mash conversion efficiency to do that.  I now question if I can accomplish this with Beersmith or if I will have to start using promash because it doesn't taint Mash Conversion Efficiency with various post boil losses (as per its FAQ). Of course I will still use Beersmith for recipe calculations and I hope the designer might offer some feedback to let me know if their is any way to accomplish solely measuring Mash Effeciency with Beersmith.

[jomebrew]

In my experience, Batch size refers to the amount you plan to put in the fermenter.  In my case, it really means how much wort I have left in my kettle that could theoretically go into my fermentation vessel.   

I see brewhouse efficiency based on this value.  I measure gravity from the wort left in the kettle before I transfer. 

[koopa]

Still hoping for feedback from Beersmith on this question......

SG is a concentration of sugar in the water so loss of overall volume does not change concentration. While I understand why such losses factor into the concept of "Brewhouse Efficiency" they shouldn't play a role in the estimated OG in my opinion.  The OG of your beer is the same post boil, post transfer losses to the primary via the chiller, post transfer losses from fermenter to bottling bucket and to bottles.  So why should the expected OG change when I modify such loss factors by changing the "Batch Size" on Beersmith then?

[MaltLicker]

So why should the expected OG change when I modify such loss factors by changing the "Batch Size" on Beersmith then?

I think the expected OG is directly tied to Batch Size and the EE%, with any losses already factored in. 

I leave 1.2 gallons in the boiler and enter that as loss.  Batch size is 4.25 gallons.  That tells BSmith I need to finish with 5.45 gallons post boil.  My evap rate tells BSmith what my collected wort pre-boil target must be to have 5.45 gallons left post-boil. 

That 1.2 gallons I don't ferment still gets sparged and still gets concentrated by the boil.  My lautering efficiency is usually 79%, but my overall efficiency is bad, like 57%, because I 'choose' to lose 20% by leaving it in the boiler.  If I did not "modify such loss factors" in BeerSmith, my calculations would be way off.  With a "lossless system" my brewhouse efficiency would be around 79%. 

Let's assume a loss-less system and batch size of 5 gallons.  Plan to collect six, boil away one, finish with five.  Spill one on floor.  If you don't enter the loss as lost, your EE% looks horrible.  As a loss, it is accounted for, and your performance looks better. 

Not unlike mega corp taking a one-time accounting charge for some failed merger or other nonsense.  If it is accounted for, regular operations look better. 

[acacko]

... to go one step further...

I know I'm going to leave 1 gallon of trub in the boil pot,
so I scale all receipes up 1 gal., and I enter the 1 gal in the
'trub loss' field