Need a little help

[Dan Prestridge]

I have a fairly new WSM 18.5. I've cook on it about 5 times. The two times that I cook Brisket on them the finished in 6 hours and these are 12lbs packer briskets. I am cooking 230. I filled the water pan with lava rocks . the brisket reach an internal temp of 165 at 2.5 to 3 hours in the cook. Any advice on how to slow the cooking proocess would be great.

 

[Jeff R]

It will slow on its own at that temp. You are just about into the stall and the temps will not continue at the same rate. Things sound normal

 

[Bob Sample]

How are you checking the temperature of the cooker. I suspect your thermo is out of calibration and your actually cooking at a much higher temperature, no way a 12lb brisket should be finished in 6 hours at 230 degrees.

 

[Gary S]

I would cook a HH brisket about 10 lb. trimmed in about 5-5 1/2 hr. so to me your cooking a HH brisket not low and slow. I use a clay saucer. Never tried lava rock but I would think it should work in a similar way. Heat sinks like that do keep getting hotter if you don't cut back on the vent settings.
I have two 18's and in order for me to cook HH I used a spike to get the lid up allowing more air in the beginning. Like Bob says check your therm. If you are running wide open to stay in what you are thinking is the 230 range then it has to be your thermometer.