I recently got a new brewing equipment, an automatic brew kettle from Brumas. I'm trying to calibrate it to use Breesmith.

I brew my first batch using an efficiency of 70% and I wanted to brew 25 liters of beer with final boiling volume of 22 Liters (I lose about 3 liters of beer while bottling).

Beersmith told me

Total water 40.48 Liter (19.43 Mash in, plus 20.05 Liters for sparging)

Pre boil volume 31.17 Liters

Post boil volume 29.17 Liters

Post boil gravity 13.629 Plato

I got

Pre boil volume 37.5 Liters

Post boil 33 Liters

Post boil gravity 11 Plato

I don't know where to fix it. I changed the Boil Off Volume, Loss to Trub and Chiller, Lauter Ton loss

I don't what to fix so the software gives me the right amount of water i should use.

Any suggestions?

Thank you very much

Let's start with some confirmation of volumes. I will first assume that you added the recommended volumes of water as stated by BeerSmith. Is there any loss for dead space in your mash tun?

If the above is correct, then you added a total of 40.48 liters of water to 6.3 kg of grains.

You ended up with 37.5 liters of wort (assuming no loss in the mash tun).

Your water retention in the grain is [40.48 - 37.5] = 2.9 liters

Water absorption rate is 2.9 liters/6.3 kg = .473 l/kg or in beersmith nomenclature 0.453 fl oz/oz of grain.

Boil off volume is 37.5 liters - 33 liters = 4.5 liters for a 60 minute boil or 4.5 liters per hour.

Given that your SG was target of 13.629 Plato (1.055 SG) and you got 11 Plato (1.044), it would seem like your mash efficiency is lower than the 70% you plugged into your equipment profile.

Specifically, you had at 70% efficiency 55 gravity points at 29.17 liters for a total of 1604 points of sugar.

You actually achieved 44 gravity points at 33 liters for a total of 1452 points of sugar.

If 1604 points represents 70% efficiency, then achieving 1452 would represent an efficiency of 1452 /(1604/70%) = 1452/2291 = 63.4% efficiency.

While I have not made any corrections for temperature in the above calculations, it would be a good starting point for your next brew. As you get better numbers, you will want to correct all the volumes to room temperature to fine tune the system.