Missing mash temp and og.

[RandalG]

I've been missing my mash temp lately and was wondering if it's due to how old my igloo cooler mash tun is? It's about nine years old and I'm not sure if they wear out over time. I use beersmith and an online calculator Brew 365 Mash & Sparge Water Calculator. I used to be right on all the time but not lately.
The other thing is I've been having trouble hitting my og also. My crush seems to be fine. I use a Barley Crusher. I haven't changed anything that I can think of. I used to get 80% efficiency pretty regularly. Not sure if they are both related or not.
Thanks,
Randal

 

[helibrewer]

Your MT might be losing some insulation quality. Repeated heat/shrink cycles will cause the insulation to separate from the cooler lining. I assume your mash temps are too low? Yes, this can be related to the decreased efficiency.

You could change the coefficient in Beersmith's equipment profile for the MT to adjust for the change, you would have to experiment with this.

The "eyeball" method would be to increase your strike water temp by the amount you are undershooting your mash temp, this is just ballpark because changes in grain weight and water quantity will effect it. If you always use the same liquor:grist ratio, it will be close though.