WSM 18.5" Test Burn


 
Lew Newby

Lew Newby

R.I.P. 1/26/2024
Sorry for the length of this. I won't be cooking until this weekend and I wanted to do a test run. I did a boiling water calibration on the WSM thermometer and it read 8 degrees low. For the test run I recorded the lid temp and the top grate temp (with an ET-73). I wanted to see what the top temp would be, how long it would take to bring the temp down, and how long a chimney of briquettes would last. There was no meat in the cooker and that would change the dynamics.

I'm sure this seems silly but I wanted to see how different this was than the ECB I learned on and wanted to avoid the runaway I had with it on my first cook.

What was interesting was that when I reached max temp and adjusted the lower vents to 1/4 open the grate temp quickly got hotter than the lid temperature. Does anyone know why?

Here's the log. I tried to clean up the formatting but alas.

WSM Test Burn
Sunday, May 01, 2011
2:25 PM
Cooker: Weber Smokey Mountain(WSM)
Water pan and clay saucer wrapped with foil

NO MEAT - The Lid Thermometer reads 8? low at 212?F - Boiling water calibration
Using the Maverick ET-73 on the top grate. After the temp peaks with all vents full open I want to see how long it takes to get to 250?F when I close all the lower vents to 1/4 open.

Time Cooker Target Temp Cooker Actual Temp Meat Temp Ambient Temp
Weather

2:20 PM Lid Top Grate 83?/Sun and Windy Testing - Added one full chimney of lit charcoal.
2:30 PM 342?F 328?F All vents full open
2:40 PM 350? 344?F
2:50 PM 351? 344?
2:51 PM 351? 344? Adjusted all lower vents to 1/4 open. Top vent full open. This is time zero.
3:00 PM 322? 335? Interesting! Top grate temp is now higher - Heat sink effect?
3:10 PM 320? 322? First drop 9? in 9 minutes, this drop 13? in 10 minutes
3:20 PM 310? 312? Temp dropped 10? in 10 minutes. 29 minutes elapsed time.
3:30 PM 302? 305? Temp dropped 8? in 10 minutes. Completely closed my 2 upwind lower vents.
4:30 PM 250? 268 Stirred the coals. Temp shot up 30? in the lid and 15? at the top grate. 1 hr. 29 min. elapsed
5:20 220 250? The temp died down because the charcoal is almost all burned up.
6:05 220? End of test. Charcoal lasted 3 hr 45 min.

Max temp in the lid was 351.F
Max temp at the grate was 344 F
Charcoal lasted 3hr 45 min.
I don't understand why the lid and top grate temperatures flip flopped when I adjusted the vents.

Lesson learned - Stop the temp climb before it gets out of hand.
 
well you are right to stop the temp spike when you can Lew but a couple things.

Since your cooker is new and you haven't cooked in it yet, you have no "gunk build up". That's one thing that will help with temps in time. Also, when foiling the pan, it is normal for the grate temp to be higher than the lid thermometer. You will learn how it is as you go.

I only have a grill surface thermometer not an ET-73 or the like and I've learned that it's always about 10* hotter on the grill surface so I make sure I keep the lid temp 10-15* lower than my target temp. I also have a wind element to constantly deal with because of where I live so that's another factor I keep in mind.
 
I always used water in the ECB and when the temp started out higher in the lid but flip flopped the only thought I had was that the clay saucer had heated up and was the cause. Thanks for confirmation. I was delighted to see how long the charcoal lasted. If I had stopped the temp rise at 250 who knows how long it would have lasted. I'm doing 2 Butts on Sunday so I'll start the gunk buildup then. Starting the coals with the Minion Method will help with temp control.
 
Yeah starting MM will help with the temp control. I would use half a chimney starter to start no more than that.

Good luck and make sure you post pics!
icon_smile.gif
 
wow. that's a lot of work to go through not to have something to eat when it's all done. Promise me you won't do that again. It's so sad to think of a WSM with no meat on it burning charcoal. That just ain't right.

What's even worse is that unfortunately, you didn't really learn anything. The wsm will act differently when there is meat on it.

Say you're sorry.
 
Thanks Jerry, I deserved that. I'm sorry. Mia culpa. Won't happen again.
wsmsmile8gm.gif


I know I didn't have to do it but I'm in that stage of learning where my quest for knowledge causes me to do strange things. And - I'm a tad anal about some things. With all respect to my learned teachers (and you all are my teachers) in that $1.50 experiment I did learn several things and so did my grandson.

That said, I again swear on my WSM that I won't do it again. I'm thinking about changing my signature to "Meat or no heat".
icon_wink.gif
 
You must log in or register to reply here.

 

Back
Top