Surprising temp control

DieselkW

8 lb. pork butt - no big deal, right? Fired up the egg at 9am, smoke cleared, 350ºf closed down the vents to "I'm gonna smoke a butt" setting, smoking wood, plate setter, steel grill. Wait for temp to settle.

Rinse yesterday's salt off the hunk-o-meat, replace with black pepper, brown sugar, Dizzy Pig Raging River rub.

Set my future pulled pork into a V rack, roasting pan, and walk outside to a 149º dome. Hmmm. Cold plate setter? Sure, why not?

Bring the butt back inside, there's still bugs in late September.

Pull the bi-metallic thermo, and replace it with iGrill probe. Watch it closely - get the dome temp up to 225º and bring the butt back where it belongs. I'm a half hour later than I wanted at 10:15am... no big deal yet.

Alarm goes off on the iGrill that I had set to watch the dome at a minimum of 215º  Well, I did just put 8 lbs of relatively cold pork between the fire and the probe, so don't chase temp, be patient.

11:15, an hour after putting the butt on, I'm under 200º dome. Open the bottom vent wide, open the top vent. Temp climbs pretty quick to 220º when I closed the top vent to minimum, stuck the bimetallic in one of the daisy holes, left the bottom vent wide open.

As I write this, 11:45, I'm holding 218º this way. Air in equals air out, so if the exit air is throttled then only that much air can come in, depending on temperature. I shouldn't be surprised, and I suppose it's past time to perform a disassemble and clean with a shop vac.

I'm worried my iGrill isn't giving me accurate temps. It feels weird to have the bottom vent wide open and the dome is holding smoking temps.

I'm hoping that continued patience will show a rising dome temp - the butt temp is 60, up from 50 when I started, so it seems the fire is not too hot.

Advice?

lousubcap

If your dome thermo passes the one point cal check in boiling water then "believe your indications".  Beyond that it sounds like major air flow restrictions on the intake but if you can manage the cook temp then all is gonna turn out just fine.  FWIW-

DieselkW

At noon, she's holding 225 so I closed the bottom vent to where I would usually put it for a 300º cook.
I replaced the batteries on the iGrill and got the same temp, the daisy wheel temp is 190º.

@lousubcap - Might not hurt to boil some water and stick the probe in that, good idea.

Butt temp is up to 72º - I don't usually babysit a pork butt like this... I planned to take a couple hours and go fishing.

I guess I like Egging more than fishing.

BilZol

Unless it's real windy or I have a stoker in I always leave my bottom vent wide open, we'll, the screen is closed. I do my entire temp control on top vent. I've never had an issue with holding 225. I'll use the Stoker on the long overnighters, but if I'm up and around the house I don't go through the trouble. 

tikigriller

BilZol said:

Unless it's real windy or I have a stoker in I always leave my bottom vent wide open, we'll, the screen is closed. I do my entire temp control on top vent. I've never had an issue with holding 225. I'll use the Stoker on the long overnighters, but if I'm up and around the house I don't go through the trouble. 

This is exactly what I do. All temp control from top with bottom wide open and screen closed. Works great for this rookie. 

jtcBoynton

"It feels weird to have the bottom vent wide open and the dome is holding smoking temps."  --  You can limit the airflow with either the intake or exhaust.  Just feels strange because its not the way you normally do it.  

Check your iGrill with comparing it to readings from your Thermapen in water.  If it reads the same you should trust it.  

DieselkW

Well, I took that butt off at 10PM, when she finally got to 195º, stuck a fork in, twisted 90º and got a chunk to come with the fork when I pulled it out. Good bark, all 8lbs fell apart by punching it. I wrapped it up into 3 meal size containers and stuck it in the fridge hot. We ate it for dinner the next day (last night) after warming it with some Baby Rays in the crock pot. 

Got a chicken brining in a cooler - going to clean the egg and calibrate my thermometers before cooking tonight.