Author Topic: Batch Size Question  (Read 4589 times)

Offline vortex

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Batch Size Question
« on: April 11, 2012, 09:05:25 AM »
I have been using Beersmith for about 8 months or so.  I was just starting to get a handle on what I was doing with my old equipment (cooler with manifold and 30 qt fryer pot) when two buddies and I built a full on brew stand with 3 - ½ barrels and a pump.  Now I am struggling with what would seem to be a simple question.  Batch Size?

I have measured all the volumes that are needed: MLT dead space, loss to trub and chiller, boil off rate, etc.  So, that should be sorted.  I am doing a Brewing Classic Styles recipe, Who's Your Taddy Porter, so that I have good solid starting point for the numbers and know reasonably well what to expect.  The Wort boiling instructions are as follows: All of these recipes are designed to leave 6 gallons of wort in the kettle at the end of the boil. It is assumed 5.5 gallons are transferred to the fermenter and this will yield a full 5 gallons of beer into packaging after loss due to trub. For most recipes, the boil time is 60 minutes at an evaporation rate of 15% per hour.   I have set everything I can find to mimic this in Beersmith.  My loss due to trub and chiller in the boil kettle is .5 gallons. My measured loss due to cooling is .35 gallons. My measured boil off is 1.1 gallons per hour.  My Brewhouse efficiency is set to 70%.  So I should have what I need to get the predicted numbers right.

However, when I input the recipe (9.5# Maris Otter, 1# Crystal 40L, 1# Brown Malt, 10.1 oz Chocolate Malt) and have the Batch size set to 5.5 gallons (what I expect to put in the fermenter) I get an Est Original Gravity of 1.057.  Jamil states an OG of 1.052.  Now when I switch the Batch Size to 6 gallons (the expected volume in the boil kettle after cooling) I end up with  an Est Original Gravity of 1.052.  I may have just answered my own question, but it runs contrary to other answers to this question that I have seen here.

So, could someone let me know which volume I should be using for the batch size, the volume I expect in the boil kettle after cooling or the volume going into the fermenter? Oh, and the reasoning.  As you all know this plays a big role in all the calculations that Beersmith does.

Offline tom_hampton

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Re: Batch Size Question
« Reply #1 on: April 11, 2012, 08:02:34 PM »

http://www.thebrewingnetwork.com/forum/viewtopic.php?f=2&t=27329

You also need to scale Jamil's recipes for your efficiency.  He's said that he designs around 70%.  I would reduce the base-malt to get the target OG.

-tch



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Offline vortex

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Re: Batch Size Question
« Reply #2 on: April 12, 2012, 11:37:23 AM »
After reading the link I found that post 12 by ChrisNH was the most help in recommending a course of action.  He suggests to remove the Trub and Chiller loss from the equipment and put it in the fermenter loss, setting my Batch Size to 6 Gallons.

As I have brewed with my current set up only 3 times and only gotten good numbers for calculating efficiency once, things like pumping sparge water into the boil kettle while boiling and a malt bill mix up tend to throw off the numbers a bit, I don't yet have a good handle on the efficiency of my setup.  I have set it to 70% in beersmith, which should be the same as the recipe parameters.