Vents


 

JacobAJensen

New member
I'm a new WSM owner and I'm still learning the ropes. In my reading about temperature control, I've come across two different (and contradictory) philosophies. The first that I hear most people talk about is to keep the top vent wide open and modulate temperature by changing the bottom vents. The other (advocated by Harry Soo) is to leave the bottom vents alone and modulate temperature with adjustments to the top vent. This is what Harry Soo says:

"Of the three components I mentioned: intake, fuel choice and amount, and the exhaust, the most effective component to maintain constant temperature is not the intake nor the fuel. It’s the exhaust. Many beginners I come across are not aware of that. All seasoned pitmasters know how to intuitively draft their pit using “clean” smoke to color and flavor their barbecue meats. The draft refers to the vacuum effect when you open or close the exhaust vent of your pit. When you open the exhaust vent on the WSM, you allow hot air to leave the pit and this creates a vacuum suction to draw air in from the bottom intakes. Thus, by skillfully manipulating the top vent, you can control your WSM like a pro. Many beginners constantly fiddle with their intake dampers in hopes to maintain a constant temperature with less success than leaving the bottom vents untouched and fiddling with the top vent to control the draft within their WSM."

Can anyone speak from experience which method you use and what is best?
 
Pass the popcorn!
I will be watching this one to be sure!
I’ve always thought it was better to adjust intake but, I’m willing to learn something different.
I see the mechanics that the esteemed Mr. Soo is talking about and am very interested in what the discussion will show from wider experiences.
 
Another way of looking at it ... On car engines with carbs, where is the air flow controlling valve (butterfly) located... in the intake or in the exhaust system ?
 
I think these are the key words by Harry:
"All seasoned pitmasters know how to intuitively draft their pit using “clean” smoke to color and flavor their barbecue meats."

I've always felt that if you don't have a very clean burn, then closing the top vents too much sets up a good chance of putting a creosote taste on the meat.

 
I tried the wide open bottom vents and regulating with the top vent on my 18.5 WSM. The results were not good, I had to choke down the top vent so much to keep a 250 temp that I had black smoke coming out.
Maybe to many coals lit, the high winds we have here giving the coals a blast of oxygen through the wide open vents or the thin air at 5500 ft. I don't know for sure. Maybe a combination of the bottom vents half open and regulate with the top vent.
I didn't ruin the roast but came real close.
 
I don't claim to be in Harry Soo's league, but I leave my top vent wide open and control the fire with the bottom. I can keep my temps steady for hours without fiddling, even overnight, with TBS.
 
I've found, for me, that the trick is to light the charcoal slowly and begin controlling the WSM temp early on. Right after lighting my pit, usually either minion or snake depending on what I'm smoking, I'll leave the bottom vents open and as it creeps up to my desired pit temp, I begin to gradually close the three bottom vents. I leave the top vent wide, or almost wide open. I use an ATC so by the time my desired pit temp is obtained, the bottom vents almost completely closed and I let the controller take it from there. What you don't want to do is start things too hot and let the pit temps spike. If it's a hot day, it can be a bear getting the temps back down. This has always worked well for me so I haven't done too much experimentation with using the top vent for temp control.
 
I’ve always done top open and throttle back with th bottom like Lew and Cliff. The creosote factor is what I’d thought would happen when just using the top vent control. It sounds like my intuition is in line with the general idea offered by people much more well experienced than myself. I’m not as dim as I thought I was!
 
Hmmm... I admit, I do use the top vent but generally I use the intake to control temp. The top vent usually makes pretty drastic changes. Usually, I use the top vent in the case that I'm trying to tame an overtemp situation and then I don't move it much. The problem with the top vent is if you shut it too much you risk dirty smoke. I'd learn your bottom vents well before fiddling too much with top.
 
I’ve always done top open and throttle back with th bottom like Lew and Cliff. The creosote factor is what I’d thought would happen when just using the top vent control. It sounds like my intuition is in line with the general idea offered by people much more well experienced than myself. I’m not as dim as I thought I was!

What Tim said............
 
Another topic, or addressed here, is getting a clean burn, clean smoke, something I could never do very well on the stick burner I once had.
I've learned to let the smoker, kamado or WSM, burn until the white or dark smoke clears.
I used to fire up my WSM, and put the meat on right away.
 
I think over-smoking can be an issue if you're a beginner. I'm guessing that he burns pretty clean and uses it to his advantage. The phenols and carbonyls responsible for smoke ring production might also "hang" around longer, thereby enhancing the smoke ring. It would explain, to some degree, why his brisket photos from class have such deep smoke rings.
 
Heck; now I'm questioning something that I do. But anyway, I have always started with the intakes and exhaust opened 100%. Then as I approach my target I throttle-back the intakes and it is quite common for them to be approx 10-15% open while I cruise at my target for quite a while. But what I am questioning is there are times later in the smoke that I tweak my exhaust a little bit, probably no less than 75% open.

I feel like I need to smoke something now to understand when and why I tweak the exhaust. Maybe it's adult beverage related. If I recall correctly the Weber manual advises to control temps by adjusting intakes and leaving the exhaust fully open (and I think they advise to do the opposite on a Kettle, don't they?)
 
I guess it would depend on what your target pit temp is, and if you use a heat sink or not.
I learned long ago that mine settles in nicely @ 275 with an empty foiled pan with no muss or fuss, so I adjust my timing and just go with it.:)

Tim
 
I tried regulating heat with the top vent several times,
but it built up creosote on the bottom side of my 18'5" lid.
Nasty smell and the creosote started flaking off and falling
onto my grill. Since then I have always used the bottom
intake vents and have never had a problem with creosote.
 
Donna;
That is an EXCELLENT illustration! I've been using the bottom vents to control, leaving them wide open until 200 degrees then closing them down to control temps on the way up. I often adjust the top a bit (never below 50%) for final control. I mostly smoke at 275 for both butts and ribs. Keep in mind, that I am just an avid amateur. Harry Soo's instructions on this forum has really been responsible (along with other good people like yourself) to raise my standards. I truly appreciate the help I have received over the years...

Keep on smokin',
Dale53:wsm:
 

 

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