Why do we add the sparge dead space if there is zero loss to boil kettle?
The Grainfather brewing system is designed for efficient water usage, with most volumes being recoverable during the brewing process. While there is a space between the intter basket and the boiler base, this isn't technically "dead space" since the liquid can be recovered. This space must be filled with water initially to ensure proper grain saturation during the mash.
Calculating Brewing Volumes
To determine the correct water volumes, start by calculating backwards from your desired batch size:
Preboil Volume = Batch Volume + Boil Losses + (Boil Length × Boil-off Rate)
For the mash water calculation, use this formula:
Mash Volume = (Grain Weight × Mash Thickness) + Mash Tun Dead Space
When calculating sparge water requirements, you need to account for any equipment-specific dead space, particularly when using a hot water urn for sparging. Hot water urns typically have a tap positioned above the base, meaning some water will remain unrecoverable below the tap level. Use this formula to calculate the required sparge volume:
Sparge Volume = Preboil Volume - (Mash Water - (Grain Weight × Grain Absorption)) + Sparge Dead Space Volume (if applicable)
This comprehensive approach ensures accurate water calculations throughout the brewing process, leading to more consistent results in your final beer.
(Reference: Daniels, 1996)