Expected Boil off for 50L batch?

[Ciderman]

I use beersmith for writing my recipes and just run standard 23-25L batches. Depending on boil time I would usually have 33 (60m) and 36 (90m) Litres pre boil. My end amount is about 25L before wort is removed off trub. I have size capacity to get that to 50L and will be doing this in the near future.

With updated Boil size on beer smith it's saying something ridiculous like 1.7L boil off. I can override it and I'm happy to have a guess at it but can someone provide any accuracy or help with beersmith. I just use it on iPad.

 

[manticle]

Your system mate. You need to measure and enter in the actual figures.

My evaporation will be different to yours.
Remember all else being equal, the percentage will not be the same for 25 L as it will for 50L but the volume loss will.

Say you lose 6L in an hour with 25, you'll still lose 6 in an hour with 50.

 

[Ciderman]

Makes perfect sense. Thank you.

 

[Rocker1986]

Just been doing this myself actually, except the other way. I have my Beersmith BIAB profile set up for 25 litre batches (I no-chill in 25L cubes), but yesterday I bought 3 new 20L cubes, and so I had to create a second BIAB profile for these ones. I decided I could probably stretch it to 21L batches in these, and so I simply copied the original profile and reduced all the strike water, pre-boil volume etc. by 4 litres, kept the same boil off volume. The boil off percentage of course did change, going from 10% to 12%, but the volume lost won't, being the exact same system.

I'll come up with a recipe soonish for the next brew day, and give it a trial run and see how we go.

 

[MitchD]

In beersmith there is a button called "Scale recipe" It keeps the same profile losses but just allows you to change the intended final volume. This is the only button you need for adjusting recipes up and down for the same system.

 

[barls]

my system is 56 pre boil and 44-46 post.

 

[Rocker1986]

In beersmith there is a button called "Scale recipe" It keeps the same profile losses but just allows you to change the intended final volume. This is the only button you need for adjusting recipes up and down for the same system.

Yep I have used that, and it definitely works as you've described. I just figured it would be nice to have two separate profiles for the same system based on batch volume, so I created the secondary one. This way I can simply choose which one I need depending on what size cube I plan to put the batch into.

 

[Matplat]

I can't understand why boil off is specified as a % value, the volume lost to evaporation has nothing to do with the volume you are boiling.


Simple litres per hour would make much more sense...

 

[Rocker1986]

That's how I input the boil off rate in my two Beersmith profiles. I agree that it makes much more sense than a % figure.