The Calculations used in the Recipe Creator on the app are as follows:
- Mash Volume = (Water To Grain Ratio x GrainWeight) + Mash Tun Deadspace
- Sparge Volume = Preboil Volume – Mash Volume + (Grain Weight x Grain Absorption Ratio)
- Pre Boil Volume = Batch Volume + Post Boil Losses + Boil Off Volume
What those terms mean (for example G30 Brewing unit):
- Water To Grain Ratio = 2.7 (litres of water per kilogram of grain. Common value used in brewing. Optimum value for mashing in G - Series from testing)
- Mash Tun Deadspace = 3.5L dead space between the base and bottom of the grain basket
- Grain Weight = total grain weight of all the grains included in the mash – exclude late sugar additions weight
- Grain Absorption Ratio = 0.8 (ratio to determine the amount of water that is absorbed in grain which will be removed after sparging)
- Post Boil Losses = 2L (rough estimate. Includes both chiller losses and trub loss in the boiler. Will change depending on the amount of kettle hops and determination of brewer to maximise fermenter volume.)
- Boil Off Volume = Evaporation Rate x (Boil Min/60) (water volume lost to evaporation during the boil. This will depend on the boil time and evaporation rate)
- Evaporation Rate = 3L/h for 230V, 2L/h for 120V (evaporation rate is lower for 120V GF models as it has 1600W heating element rather than 2000W)
- Batch Volume = final volume in the fermenter after chilling and transferring. Note that there will be some fermenter losses so this final keg or bottle volume will differ.