BrewTarget / new at all grain questions

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

ChandlerBang

Well-Known Member
Joined
Oct 23, 2010
Messages
3,034
Reaction score
26
Location
Earth
So far the most complicated I have done is PM kits from AHB, so I am learning brewing software and the AG process at the same time. Please forgive base questions.

When adding equipment, what is the mash tun volume, mass, and specific heat? I will be using a 15g extreme cooler. (I know it is huge, but it's handy, I have it and I won't use it for anything else)
I assume volume is 15g, but is mass the mass of the tun empty? Or is BT trying to use mass and specific heat to calculate strike water based on an un-preheated MLT?
What happens if I leave these perimeters at "0"?
More questions to come, I'm sure!
 
When hot water and cool plastic mash tun come together the temperature will equalize a few degrees cooler than the original water temperature. The more cool surface area your mash tun has (bigger the mash tun basically) the more it's going to cool your strike water down. They're trying to figure out how much by this calculation. 15 gallons isn't all that huge, so you're going to lose a few degrees max. I never bothered with that calculation to be honest. The more important figure is the temp of your grans and your desired mash thickness, as these will take the most heat out of your water.

For example if you have a 1.25qt/lb mash thickness, and the grains are at 70F, you'll need 169F strike water to equalize to a mash temp of 153. When you heat your strike water to 169, by the time your thermometer reads 169 and you cut the gas, the residual heat in the kettle will have already raised the water temp another degree or two.

Dump the strike water into the cooler and close the lid. Wait a min for everything to equalize. Then take the temp of the strike water again, it might even be a degree or two too high. If this is the case just stir the water for a minute and it will drop quickly a degree or two until it's exactly right. Then mix the grains and take the temp again, you should be spot on. If you are still a degree high just stir another minute and it will be right.
 
I'm sorry, I should have clarified my question. I understand the basic theory of mashing and sparging. What I don't understand is how these inputs will affect my numbers in the program. But thanks for the lengthy explanation.
 
They will affect the calculated temperature of your strike water. If you were to put in 0 for the weight and/or the specific heat, your strike water will likely be a few degrees low simply because the mash tun will suck up some of the heat. If you preheat your mash tun, this is likely a negligible error. I don't preheat my mash tun, and I find there is about 4C lost to heating the mash tun.

The numbers are a rough approximation. A lot of assumptions are made to simplify the math (e.g., you are not heating the entire mass of the mash tun, but the formula assumes you are). The best thing to do, most likely, is a test run like what cvstrat suggested.
 
Back
Top