# Increasing mash temp by adding hot water rather than heating the mash?

Maths was always my worst subject....

I have a fixed lauter-grill/filter at the bottom of my mash tun so i can't stir anything that falls through it = the gas burner gives me a burnt bottom :(

Thoughts about adding hotter water to the mash to raise the temp rather than using the gas, or a combo of both? If you think doable, please help me work out the numbers for say a 500 litre mash :)

Equation something like:

250L @ 57C to mash in (for 10 mins).

Add 100L of hotter water @ X degrees C = 350L @ 66 degrees C (for one hour).

Add 150L of hotter water @ X degrees C = 500L @ 78 degrees C (for 15 mins).

I worry about ever seeing water in a mash go above 78C (sour flavours appear) so am reluctant to add anything even close to boiling water, although added slowly may dilute the heat enough....???

Thoughts appreciated!

Cheers!

• Look up decoction first. The problem with adding hot water is that your mash gets thinner and thinner, and you need more and more water. Nov 14, 2017 at 17:49
• Totally off-topic, but if you got a burnt bottom, then you have to sit on the blisters :-p Nov 14, 2017 at 18:34
• Nice one! I will look it up. Many thanks for the lead. Nov 14, 2017 at 20:19