I'm brewing BIAB no sparge but want to follow Greg Hughes recipes, which seem to only cover the full-mash method. I need to know how much water to add at the beginning to end up with 23 ltrs of wort and what temp the water needs to be at to end up at the right mash temp once the grain is added. How can I work this out????

Hi you need to add as a rough guide 1 litre of water extra for every kilo of grain as this will be lost by absorption plus boil off amount as well. My system loses about 4 litres in a hour but again every system is not the same so as a guide 23 litres required at end plus 1 ltr for every kilo of grain lets say a 5 kilo grain bill so 5 Ltr 4 litres to boil off ( plus you will have some trub left behind so may have to add this in as well but you can put it all in the FV if you want) so 32 litres is a good place to start but it will be trial and error until you have brewed a couple of times and get to know your own system also be careful of full mash with tap water as you may get PH problems which can cause astringency in the beer. I would use 5 x 2 Ltr bottles of cheap water Asda smartprice or Aldi EE water both about 17p each as this does help with the PH but many people have no probs with tap water and add a campden tablet the night before if poss to get rid of the chlorine

For the mash calculation x the grain bill (lbs) by 0.34 + 0.9 = gallons And for the sparge calculate your final volume say (5 gallon) +1.4 - 4.9 +12 x 0.1 = gallons