Brewsmith cooling shrinkage with BIAB

[friartuck]

I have a question regarding the cooling shrinkage calculation when dealing with a BIAB type setup.

I do a no-sparge style BIAB and fill my kettle with the full volume right out of the gate. This is cold water, which I then heat to strike temperature, add my bag and dough in.

It seems to reason that I should set the cooling percentage to 0% in Beersmith as I'm starting with already-cold water that will expand when heated, and then contract again once cooled.

Can anyone confirm/deny my suspicions? Thanks!

Edit: spelling. doh!

 

[Doed]

You know I never thought of that but I can see what you mean. I brew the same way. Is there anyway to tell other than starting with a precise amount, heating it, and then letting it cool and re-measure?

BTW, there is an actual software board on HBT that this question probably should have been posted in.

 

[TopherM]

You lose a small % of water to evaporation while it is cooling down, not contraction. Most people set this to 0.2 gallons in BeerSmith II and get accuate results.

 

[friartuck]

BTW, there is an actual software board on HBT that this question probably should have been posted in.

Crap. I'd been searching for answers to this very question and the last few Beersmith questions were in the AG board.

Would a friendly mod relocate this? Thx!

I'm going to guess that the cooling shrinkage percentage is assuming you're adding already-heated water. Here's hoping someone more knowledgeable on the software (and the whole science of the matter) will chime in!

Thx for your reply!

 

[friartuck]

You lose a small % of water to evaporation while it is cooling down, not contraction. Most people set this to 0.2 gallons in BeerSmith II and get accuate results.

The recipe has a spot for 'Pct Cooling Loss' and the tooltip says 'Percent of volume lost due to shrinkage' -- I don't think this is the same thing you are referring to.

 

[JeepDiver]

The % of volume is from your post boil volume, so it doesn't directly relate to the volume of water added to being with before heating.

You actually have to build the water voulme from the end of the process back up

If I want 5 gallons in my fermenter and I lose .5 gallons to trub/deadspace loss and 4% going from ~211 degrees to 70 degrees, then I will need ~5.73 gallons post boil to end up with 5 gallons in the fermenter.

The you have to add boil off, grain absortion, etc to get your starting volume.

Though this does lead to a question on if BrewSmith takes into account the expansion, when figuring the amount of water you need to begin with.

 

[wilserbrewer]

It seems to reason that I should set the cooling percentage to 0% in Beersmith as I'm starting with already-cold water that will expand when heated, and then contract again once cooled.

Can anyone confirm/deny my suspicions?

I think you are correct.

 

[JeepDiver]

You lose a small % of water to evaporation while it is cooling down, not contraction. Most people set this to 0.2 gallons in BeerSmith II and get accuate results.

It's not evaperation, it is from Volume expansion/contraction

 

[friartuck]

Though this does lead to a question on if BrewSmith takes into account the expansion, when figuring the amount of water you need to begin with.

Exactly -- from what I can tell, it most certainly does, which makes sense as you're typically working with hot water from the start in a typical all-grain setup, vs filling full volume and THEN heating it.

 

[barrooze]

It's a very good question, and one of the best things about BeerSmith is that it is actively maintained! Shoot Brad an email and ask him directly. Get the definitive answer from the software's author. Be sure to let us know what he says so we can all answer this in the future.

 

[friartuck]

I've actually sent an email off via their support form. I'll definitely report back!