Steps for 23L batch, 5kg grain:
- Preheat mash tun
- Mash in with 2.5x weight of grain (12.5L @ 75°C)
- Ensure temp is 65°C (low body) to 68°C (high body), adjust with hot/cold as necessary
- Leave for an hour or more, stirring every 15 minutes to avoid cold spots, checking temp each time
- Mash out with very hot water (8L @ 100°C) to raise temp to ~82°C, stir
- Drain and recirculate, all of the wort out
- Add sparge water (15L @ 82°C), stir, leave for 10 mins
- Drain and recirculate, all of the wort out
- Total, 30L
- Do boil, chill with wort chiller, syphon into fermenter, leaving cold break behind
What I do is, mash in with 2.5x weight of grain; I.e 5kgs grain 12.5litres of water. Your grain will absorb 5litres of water and you will lose some to evapouration, trub etc. You need to know more or less what evapouration and loss to trub you will get, a good evapouration figure is 9-15% and a couple of litres to trub, I’m digressing.
So you mash in with 12.5 – 13litres of water wait for an hour or perhaps a little longer. Mash out using very hot water (near boiling) stir leave for about 10mins, stir to disolve as much of the sugars as possible. (how much mash out water to add?) What I suggest is to try and get two equal run offs from first runnings and sparge water. Lets just say for ease of arguement that you are aiming for 30litres of wort preboil, I.e Two equal run offs of 15litres, so in our example we added 13litres – 5l (loss to aborption) plus dead space in mash tun (estimating 1l) so we have a max. total possible run off of 7litres, but we are aiming for 15litres; therefore add 8litres during mash out. Drain and recirculate into kettle, close your mash tun tap then add hot water to sparge 15litres. (Temp should be in the 90’s) I’m talking about batch sparging here not fly sparging as the technique is different.
Anyway digressing again, so we’ve added the sparge water, stir and allow to settle for 10minutes, recirclate then drain into kettle. You should have 30litres preboil, but will have 9-15% evapouration during the boil, loss to trub, etc and should end up with around 23l for the fermenter.
Sorry if I’ve confused you.
AC
