The last batch I made I was able to hit my mast temp. within a degree. The one caveat is that I didn’t stir the grain very long, which I plan to do this go around. My fear is that I’ll undershoot my temp.
Do you have a good rule of thumb on what temp. to heat the strike water up to to hit a particular mash temp?
FWIW, I’m using a 10 gallon rubbermaid round MT and my mash temp. target will be 153.
Each system is different. It also depends on how you transfer the water. On average, my strike temp is 16 degrees over my target mash. If my mash is thinner, I’ll drop the strike a couple degrees. If it’s thicker, I might raise it. I think it’s just something that you get a feel for.
Just to confirm…it’s easier to just let it cool naturally vs. trying to heat up correct? Maybe I’ll err on the hotter side just to be safe until I know.
I think I’m using 1.5. Actually, at this point I Just try and get equal volumes of water for my strike and sparge water to simplify my process at this point which normally is around 1.5 based on my inputs.
Yep. Stir until you drop it to your goal. I’ve overshot by quite a bit a couple times, and I just added a bit of cool water, then subtracted this quantity from my sparge volume. A little bit goes a long way.
I would rather come in a couple degrees under with a uniform mash temperature than take a measurement that appears right but came out of a mash with pockets or layers of different temperatures.
The trickiest part of calculating a strike liquor temperature value is determining the thermal loss to the tun itself. You will need to add 4 to 6 degrees Fahrenheit to strike_liquor_temperature to account for this heat loss. I would add 6 because you are using a large tun for the amount of grist that you are using. As an alternative, you can preheat your tun, and then just go with strike_liquor_temperature. If you do not mind overshooting a bit, I would use strike liquor that is 16 degrees (18 degrees will definitely give you room to adjust down) hotter than your desired rest temperature. As you have assumed, it is better to overshoot and cool than to undershoot and have to calculate the amount of hot liquor at 100C/212F necessary to hit your strike temperature.
Good idea. My SOP has been to add room temperature water which can take quite a while. Some times I give it up when I get kinda close. Luckily I know my system pretty well and usually get pretty close on the first shot.
Denny is correct. Ice is better than water when it comes to cooling a mash with a minimal increase in volume. It takes almost as much heat energy to thaw a gallon of water in ice form at 32F to liquid form at 32F as it takes heat a gallon of water from 32F to 212F. This amount of heat energy is called the latent heat of fusion. Latent heat of fusion is covered in the “Heat transfer and refrigeration” chapter of “Brewing” by Lewis and Young.
You’re welcome. It’s one of my favorite brewing textbooks. While not for the beginning brewer, one can tell that the authors are experienced teachers as well as experienced researchers.
I do BIAB and find that I just need to heat the water to the recommended mash temp. Any more than the prescribed temp and it is too hot. And I am using a digital thermometer which is presumably fairly accurate.
I’m puzzled that one of the guys posting above said he needs to go 16 F above to get to the mash temp. Is this because you are adding water slowly into your mash tun?
Heated up to 175 (22 degrees higher) than I needed to this morning. Found out quickly that that was way too high. Stirred for about 10 minutes on and off and added a little ice to remedy it. Made some good notes for next time.
Put about 8 oz. of boiling wort into a metal cocktail shaker. Swirl it in a bow of water for 45-60 seconds. It will be down into the mid 60s at that point so you can take a hydrometer reading.