10G Batch with a 15G eBIAB setup

[smik]

Hey Folks,

Did some searching on the boards, but can't find an answer.

I'm looking to make an 10G batch in my 15G eBIAB pot.  Since that size pot is too small for a 10G full BIAB mash, the best way I can figure to do this is to do a mash that yields about 9 gallons (let's say) @1.059 then, before the boil, add 2.5G of water that should yield me me 11.5G of 1.046 pre boil.

After a 30 minute boil (and cooling) I should be left with a final volume of about 10.5G of 1.050 wort - ready for the fermenter.

Now, here's the question.  I did all the calculations above with the BS calculators (Dilution and Boil Off tools) - can I set up a profile to do all this automatically with BS or is that just asking too much?

Thanks in advance!

[GigaFemto]

Yes! I routinely make BIAB batches with more grain than my kettle can handle if I mashed with full volume. Use the "Kettle Top Up" entry on the Volume tab to account for what you are doing on an ad hoc basis, or put it into your Equipment Profile. In the Equipment Profile it is on the left, at the bottom of the "Mash and Lautering Adjustments" section. Set the "Top Up Water for Kettle" to be 2.5 gallons and BeerSmith will do all the right calculations (including strike water temp) properly.

--GF

[smik]

Thanks GF.

So I checked it out - and it looks like it does everything required from a water volume perspective.

Follow-up question.  Where do I find the metrics that I need during the process - that is mainly the post mash gravity (before top up)?

[Oginme]

On the 'session' tab, you will see the estimation of post mash gravity (2nd column under Mash Efficiency).  This is differentiated from pre-boil gravity (3rd column under volume and gravity into boiler) which contains the volume of top off water and any post mash, pre-boil sugar additions.

If you print out the brew day sheet, these numbers will show up as targets for post mash and pre-boil figures.

[GigaFemto]

One thing to note is that the water adjustments on the BeerSmith water tab apply only to the mash water, not to the top-up water. If you want to add salts to your top-up water you will have to calculate that separately. BeerSmith doesn't have a way to handle this automatically. I actually put the full volume into my kettle and add the salts for the full volume. Then I remove the amount I want to use for top-up into a separate container and add the acid to adjust the pH for the mash volume only.

--GF

[smik]

Thanks guys.

@Oginme - I'm using BS3 and I see the columns you pointed out under the Session tab - but the "Post Mash Gravity" is defined as (when you hover over it with the mouse):

"Gravity of wort as measured after mash and boil top up, but before sugar and extract additions"

So I still can't find anything that that gives me the SG of wort post mash (without top off)... ?

@GigaFemto - good tip on full volume of salts in the kettle and then pulling off the top off water!

[Oginme]

smik,

You are correct.  I don't usually top off, so I didn't check.  Shame on me! 

The program is using the pre-boil volume to calculate the number, which is why it does not appear to have the estimated reading from the mash alone. It is not hard to figure since there are no sugars in the top off water, the estimated gravity post mash and before top off would be:  [(post mash gravity - 1) *1000 * pre-boil volume] / [pre-boil volume - top off water] / 1000 +1