Strike water temp...who do I believe?

I have formulated a DFH 90 minute clone into Brewtarget and seem to be pretty close with all my numbers. This is my first all grain so I am double and triple checking everything.

The biggest discrepancy I am seeing is strike water temperature. Brewtarget is saying 162*, the Green Bay Rackers mash calculator says 169*. That is a pretty big difference. So how do I know which is right?

I could check with BeerAlchemy for a third opinion if you post the grain bill, etc.

this is the recipe https://www.homebrewtalk.com/f69/dogfish-head-90-minute-clone-260675/

Grain bill is:

16lbs 2 row
1lb amber malt

Using the 1.25 qt/lb ratio and assuming my mash tun will be about 60* Shooting for 149-150 mash temp

Assuming a Tun T/M of 0 (meaning you pre-heat your MLT), BeerAlchemy gives me a strike temp. of 161F with the parameters you provided.

I wasn't planning on pre-heating the tun, I figured if the tun was 60* then the calculations would compensate for that by raising the temp slightly. The rackers calulator doesn't ask for tun temp, only grain temp...Brewtarget actually asks for the temp of the tun which I put 60 and it still gives me 162

Honestly, I'm not quite sure how the rackers calculator works without inputting a grain bill size. I would think that 10 lbs. of grain would absorb more heat than 1 lb.

That said, I routinely calculate my strike temp. with a Tun T/M of 0 and add 8 to 10 degrees to pre-heat. Once the temp. settles at the calculated strike temp., I dough in. That way I know the the tun has absorbed as much heat as it will and then I just rely on the grain to absorb the remaining heat to get me down to the desired mash temp.

I would think that the tun's ability to absorb heat T/M would affect the strike temp. Not just the temp.

Hopefully, someone else with brewing software can chime in.

I suggest preheating the tun. The one time I didn't the mash temp was almost 10 degrees below what I was shooting for. I can't remember exactly and do not have my notes available but I thing I had the water at 165° looking for 153° and got about 145°.

I've been using this and have been spot on on my last 2-3. Brewheads.com - Batch Sparge Calculator

You really have to preheat the MLT if you have a cooler! I actually add 185 degree water to mine, and let it cool. Even then, it cools fast, especially this time of year, to the correct strike temperature. If you don't preheat your MLT, you will never hit 150 degrees for the mash with a 162 degree strike temperature. The MLT sucks out all of the heat, and your mash temp will drop like a rock.

I second what Yooper said.

brew2enjoy said:

I wasn't planning on pre-heating the tun, I figured if the tun was 60* then the calculations would compensate for that by raising the temp slightly. The rackers calulator doesn't ask for tun temp, only grain temp...Brewtarget actually asks for the temp of the tun which I put 60 and it still gives me 162

Click to expand...

There's your answer on who not to go with.

Ditto. I have tried to compensate for not preheating, but the calculations are always off. Put some hot water in there and let it SOAK IN.

I always try and shoot just a little high as well. It's always much easier to cool your mash than to try and heat it up.

Yooper said:

You really have to preheat the MLT if you have a cooler! I actually add 185 degree water to mine, and let it cool. Even then, it cools fast, especially this time of year, to the correct strike temperature. If you don't preheat your MLT, you will never hit 150 degrees for the mash with a 162 degree strike temperature. The MLT sucks out all of the heat, and your mash temp will drop like a rock.

Click to expand...

Thanks, this is pretty much what I was thinking. I'll just heat the water an extra 10-15 degrees and wait for it to drop to 162 and then dough-in. BTW I am using a 10 gallon round Coleman cooler. Haven't used it yet, first all-grain batch!

Thanks for the help everyone!

brew2enjoy said:

Thanks, this is pretty much what I was thinking. I'll just heat the water an extra 10-15 degrees and wait for it to drop to 162 and then dough-in. BTW I am using a 10 gallon round Coleman cooler. Haven't used it yet, first all-grain batch!

Thanks for the help everyone!

Click to expand...

I'd also recommend pre-heating the MT, and also shooting for the higher strike water temp. It relatively easy to bump down the mash temp with some cold water (but don't overdo!), is a more of a PITA to have to bump it up with boiling water, heating the mash somehow, etc.

If you don't preheat the cooler, there's little point in measuring anything else, because you're just guessing. I guess that means I agree with Yooper and everyone else.

Fill the MLT with water 15 degrees or more higher than your strike temp. Let it sit for 10 min. Check the temp. If it's high (and it should be), I drain a half gallon of water into a metal pitcher and then pour it back into the MLT. I do from as great a distance as I can (i.e. pitcher as low as possible when draining, as high as possible when pouring). This exposes the water to the air and at about 60 degrees outside temp will drop the temp 1/2 to 1 degree each time I do it. Five minutes later you are exactly at strike temp and your mash temp will be right on. I like this better than adding water or ice because it doesn't change the water volume and it moves the temperature in small increments.

L

I guess my original post was somewhat confusing, I know I needed to pre-heat my mash tun. My questions was mainly whether the mash calculators I was using were factoring the extra few degrees needed for the cooler to absorb. Now I know they don't. Thanks for all the suggestions