Is it OK to close the top vent some?


Wesley Talbot

New member
I'm 14 hours into a brisket cook now, and this is the first time I've used my 18.5" WSM without water. I've got a pizza stone in the water bowl that I wrapped in foil.

I may have started off with a few too many hot coals (half of a Weber mini chimney in the ring of fresh briquettes and a couple wood chunks), but I'm having a heck of a time keeping temps below 140 F, even with all bottom vents closed. The only way I've been able to keep it at a stable 225 F is if I close in on the top vent somewhat. I'm using a Heatermeter so it's still not too much work, but I never had an issue keeping the top vent fully open when using water in the bowl. I'm sure my WSM isn't airtight, but I do have seals on my lid and door.

Anyone else need to throttle the top vent on these low and slow cooks?
but I never had an issue keeping the top vent fully open when using water in the bowl.
That's because it is easier to keep temps down with water in the bowl since it'll never rise above 212. A pizza stone is solid, therefore can have much more energy than water, and can get much hotter than 212.

I use a plant saucer wrapped, not tightly but, leaving a foil grease catcher.
How big is your brisket! The last one I did had a secondary stall at 180 and it felt like the last fifteen degrees took an eternity!
top vent as a control is totally fine; the phobia about the smoke backing up is a myth

you can control airflow from the top or bottom or both; you can leave the top open and just control the bottom vents on the WSM; but physics says the choke can be in either place or both;

harry soo controls the wsm via top vent fyi

top vent is how you do basic temp control on a kettle

when using an atc on a wsm, you close the top vent down to 25% or less

top vent is fine; but with the design of the wsm, it is a bit easier to do your fiddling at the bottom

having quarts of water, obvi, is one way to keep temps down; since water and steam can't go about 212F; but that is highly energy inefficient and theres lots of other ways to control temp too