Can't for the life of me figure this out...

Hello all,

OK - I've done some searching and am still lost.

I've just completed my 3rd AG batch and I'm trying to figure out what amount of grain I need to hit my required gravity.

I've done a pretty good job of keeping all my stats:

Measured Mash Efficiency (about 80%)
Pre Boil OG
Pre Boil Volume
Boil off (% / Volume)

I know what volumes I want going into the fermenter (about 6-6.5G) and what I want coming out of the fermenter (about 5.75G).  I'm boiling off between 0.8-1G for a one hour boil.  I don't want to do 2 hour boils to bring the volumes into check so I guess I need to add more grain (cause I'm missing my Fermenter OGs).

If I'm missing anything here to help diagnose this issue - please let me know.  I just need to know where in the software i can "dial in" so that my grain bill gives me the right OG with my present mash efficiencies.

Also - as you progress with using BS2 - will it "learn" your efficiencies for future brew sessions?  If not - where do I need to concentrate?  What do I need to know to get the proper OGs?

This sounds like you're using Mash Efficiency (ME) to design recipes? BeerSmith uses Brewhouse Efficiency (BHE) for calculating total grain needed. BHE accounts for all losses between the boil and the fermenter.

BeerSmith calculates BHE on the Fermentation tab. If you input your preboil and postboil gravities and volumes, you'll see your BHE in the "Measured Efficiency" field. This is the number you'll want to use in your equipment profile for future recipes. It's usually less than your ME.

Here's why:

ME is the percentage of total sugars extracted into the kettle from the grain.

BHE is the percentage sugars that make it into the fermenter, from the total available.

What this means:

If you tell BS you have 80% efficiency, BeerSmith uses this for BHE. This means you expect to get 80% of all the available sugars into the fermenter. If you have trub loss, that wort will have the same gravity as the rest of the batch, of course. So, in order to get 80% of the available sugars into the fermenter, you'll need additional sugar, right?

Well then, the ONLY place that sugar can come from is higher mash efficiency.

If you are certain you get 80% mash efficiency, then to be in the ballpark, you have to reduce BHE by the same percentage as the volume of wort you lose. Once established, you'll see correct gravities and volumes in your recipes.

The place you want to focus on is your equipment set up.  Since you know your evaporation rate,  you can plug that in directly.  Make sure that your losses are reflected in the numbers for trub/chiller loss.  The tricky part comes in when trying to deal with your efficiency.  BeerSmith uses 'Brew house efficiency' as a fixed variable.  If you look through your recently brewed recipes, you should be able to make a copy and play around with the 'brew house efficiency' number on the design tab to reach an expected 'mash efficiency' which is about equal to your actual achieved mash efficiency.  Once you have done this, you can plug this number from 'brew house efficiency' into your equipment profile.  This should get you much closer.

I would also recommend tracking the total water added and grain absorption.  Once you verify this number it plugs into your overall settings in BeerSmith found under 'options' >> 'advanced'. 

Thanks to you both!  My understanding is better now (although i may follow-up with a few more questions - possibly after my next brew session)

Cheers!