low mash temps

Hi All,
I just got done brewing my second AG batch and for the second time in a row, my mash temp was low (148 both times). Both times I used the formula below to calculate the temp of my strike water. I'm not even sure where I got the formula from
I am brewing 5gal batches and using a 10gal round cooler for my MLT and I am preheating the mash tun. Do you think headspace may be an issue here? Any other ideas on why I am missing my mash temp?
Next time I will just heat my strike water up a few more degrees; but I'm curious why this is happening. Maybe the formula is just not right? Anyway, any input would be appreciated.

FORMULA-
Tw = (.2/r) (T2 - T1) + T2

Tw- Strike Water Temp
r - ratio of water to grain
T1 - Temp of grain
T2 - Target Mash Temp



---Klink

Keep boiling water on hand to fine-tune your mash temps, grist-water ratio isn't set in stone so you can add to your mash. Calculations, especially equipment mass related, are really better as a guide.

Thanks...yah i guess I should get some water going on the stove while I've got the strike water on the burner outside.

I use this calculator and it is pretty accurate.

http://www.rackers.org/calcs.shtml

The rackers calculators site is very good.


Sent from my iPad using Home Brew

It sounds like you and I have very similar setups and use the same formula as you (hooray John Palmer!!).

If it makes you feel better, I've had similar issues with trying to get my strike temp correct. Like you, it normally comes in low. My personal postmortems indicate that I'm fudging my temperatures a bit on the low side, mainly because I'm impatient. For instance, if I know I'm aiming for 152, and I need 173 water, it isn't unusual for me to look at the thermometer and decide that 171 is okay. Apparently it's not - which causes me to have 150 strike. Shouldn't be surprising I suppose, but there you go.

Today I let it go a little hot, and stirred the heck out of the grist. Mirabile dictu, I hit my temps. It's a lot easier to cool the mash down than it is to heat it up.

I use the 10 gallon cooler/tun also. Even with preheating with 1.5-2 gallons of water, I need 175F water to get 154-155F starting mash temp. The calculators are helpful, but keeping notes on what works for your system and adjusting accordingly is the best.

I use the same formula for my strike water and I always add 3 to 5 degrees to the temp depending on the time of year. That is after preheating the tun too. Just have to take notes and adjust for the next brew day.

I've had good success with this formula:

Tw=(0.24/r)*(T2-T1)+T2

So, close to your formula but will lead to slightly higher strike water temps. Maybe this will be more in line with your experience.


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Thanks for all the replies!

I have the same setup and I heat my strike water 15 degrees above what I'm shooting for then stir like crazy for a minute or two and I'm right where I want to be. Then I always heat sparge water to 185 degrees and I come in very close to 170


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All the above are right on track. I like to shoot for a mash temp a little on the high side because I don't like my water to grain ratio to get too high if I come in too low on temp. And if it is too hot I add a few ice cubes and stir until it is perfect.

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I always do things a little wacky, but if it helps: I find if I get my 7-gal kettle totally full, and bring it to an actual boil, I can pipe off enough to fill a couple of 2-gal mini coolers (or sometimes HDPE, sue me, it's safe) with boiling water to use for sparge (because it will cool to about 170 by sparging time, though I still temp it of course). Then I top off my kettle to the right volume and temp, and I'm set.

Is your thermometer calibrated correctly?