Fundamental question about temperature control


 
Jeff B

Jeff B

TVWBB Member
I'm new to the charcoal side of outdoor cooking. I've been using a Weber gas grill for 10 years and I just bought the WSM 22.5 this summer as a birthday present for myself.

After a few cooks I am getting the hang of things but I till have some fundamental questions:

Does the amount of charcoal burning control the temperature or does the aif flowing through the the vents control the temperature? For example - If I wanted a cook of 8 hours and I use the Minion method and a more charcoal than I planned ignites am I then stuck with a hotter fire or can I close down the vents to have a cooler fire? Will the fire burn longer? (Is fire thecorrect term for burning coal?)
 
Jeff, Welcome to TVWBB.

You control your temps with your vent settings, the more the vents are open, the more oxygen gets to the coals and creates a hotter fire. if they are shut down, less oxygen will get to the coals and lower your temps. weather all your coals are lit(regular method) or just some are lit(minion method) temps are still controlled by your vents.

The more lit charcoal you pour on top of your unlit charcoal when you start your WSM, will give you less of a window to "catch" your temps coming up and to start choking down the vents.

Try and maintain your temps by adjusting your bottom vents and try to always leave your top vent open(if your temps ever get really out of control and all your bottom vents are shut, you can shut the top vent down a little until you get your temps back in control.

When I cook on my 22.5 WSM I fill the charcoal ring full of unlit charcoal and then spread about 15 lit coals on top of the unlit charcoal, Add your wood chunks, assemble the cooker and leave ALL vents wide open until you reach about 200 degrees. once I reach 200 degrees I close 2 bottom vents completely and shut the third vent three quarters. and this set up for me will settle in right around 225-240 for a long time with out messing with the vents. my top vent always stays wide open.

these setting work perfect for me every time.I also don't use water in my water pan, I just cover it with Aluminum foil and run it dry. If you are using water you might have to crack open the bottom vent a LITTLE more as it takes more heat to heat the water.

Hope this helps.
 
What Todd said. Oxygen fuels fire, lack of oxygen chokes fire.
I didn't even know what the vents on my BBQ were for until I was in my 30's. I just kind of thought they let the ash fall out when it was full.
 
As has been said, air controls the heat. No argument.

However, that's not the entire answer. Having a full load to do a short cook CAN (I repeat CAN) lead to a cold or dirty fire. Try to judge the cook length and only load as much fuel as you need with a small margin. That way you can run a small, hot fire rather than a large, cold fire.

A cold fire CAN lead to that bitter creosote taste in food that nobody likes.

Russ
 
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Russ Sylvester:
As has been said, air controls the heat. No argument.

However, that's not the entire answer. Having a full load to do a short cook CAN (I repeat CAN) lead to a cold or dirty fire. Try to judge the cook length and only load as much fuel as you need with a small margin. That way you can run a small, hot fire rather than a large, cold fire.

A cold fire CAN lead to that bitter creosote taste in food that nobody likes.

Russ </div></BLOCKQUOTE>

True, and I suppose that's why it's easier to get good smoke with the water in the pan method where you start with more charcoal engaged.
 
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Russ Sylvester:
As has been said, air controls the heat. No argument.

However, that's not the entire answer. Having a full load to do a short cook CAN (I repeat CAN) lead to a cold or dirty fire. Try to judge the cook length and only load as much fuel as you need with a small margin. That way you can run a small, hot fire rather than a large, cold fire.

A cold fire CAN lead to that bitter creosote taste in food that nobody likes.

Russ </div></BLOCKQUOTE>

Russ, I agree. On a small cook there is definitely nothing wrong with a small hotter(clean)fire. With that being said numerous WSM owners from back yard barbecues to pro comp teams start with a full ring and a slow minion method with great results. You will also find a lot of people always start with a full load even for a small cook and shut the cooker down when there done and reuse what ever coals are left for the next time with great results. What ever method one chooses is fine as long as it works for them. Where all trying to turn out the best Barbecue we can. I have cooked all the
ways above(as have many others) with great result.

On a long overnight cook such as Brisket or shoulders there really is no other option(unless you want to maintain a small hot fire constantly all night) I feel Being able to do a long minion smoke 15-17 hours on one load of charcoal is one of the WSM best features, Heck that's why I went to it, staying up all night on the stick burner adding a split to it every hour or so got old. But for a short cook in the wsm a clean small fully lit fire works great also.
 
Thanks guys, this is a big help. I was concerned that if I put too much charcoal in the WSM that I would get a wildfire that was way too hot. The charcoal ring on the 22.5 is huge - it can probably take a full bag. I was afraid of overfilling it and turning the WSM into a fryer instead of a smoker. I will use the rule of thumb that the air controls temp and the amount of fuel controls the time of the cook.

The cold fire being a dirty fire is a new concept to me. I cooked a pair of pork butts last month. I started at 3:00 am and then went to bed after the fire stabilized. I didn't put enough fuel in (as I have just learned) and the temp was at 170 degrees when I came back around 8:00 am to check. The pork butts did not taste as good as I hoped. I chalked it up to it only being my 3rd cook but maybe it was the low temp creosote flavor. I hope I didn't poison my wife - no one would believe it was an accident.
 
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Jeff B:
Thanks guys, this is a big help. I was concerned that if I put too much charcoal in the WSM that I would get a wildfire that was way too hot. The charcoal ring on the 22.5 is huge - it can probably take a full bag. I was afraid of overfilling it and turning the WSM into a fryer instead of a smoker. I will use the rule of thumb that the air controls temp and the amount of fuel controls the time of the cook.

The cold fire being a dirty fire is a new concept to me. I cooked a pair of pork butts last month. I started at 3:00 am and then went to bed after the fire stabilized. I didn't put enough fuel in (as I have just learned) and the temp was at 170 degrees when I came back around 8:00 am to check. The pork butts did not taste as good as I hoped. I chalked it up to it only being my 3rd cook but maybe it was the low temp creosote flavor. I hope I didn't poison my wife - no one would believe it was an accident. </div></BLOCKQUOTE>

Keep at it Jeff, once you get your technique down, this cooker is one of if not the easiest smoker to use.
 
I think the only risk of a fire way too hot is using too large a quantity of lit coals to start with.

Most people use a 1/4 chimney or so. If you use a full chimney, and get it red hot, you can have a really hot fire for at least a while.
 
Jeff,

Lots of people have created inventive ways to have a smaller charcoal ring in the 22. I only have an 18, but I too am trying to make a smaller charcoal ring. I don't have the posts, but search for charcoal ring in the various topics and you'll find some great ideas to use less charcoal and control the heat easier. And yes, it's all about the oxygen, but it also takes practice to get the balance of hot coals and oxygen flow to create lasting heat. Good luck!
 
Thanks again everyone. I think practice is the key here. I will be doing cook #5 this weekend as a practice run for the turkey on T-day.
 
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Dave Russell:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Russ Sylvester:
As has been said, air controls the heat. No argument.

However, that's not the entire answer. Having a full load to do a short cook CAN (I repeat CAN) lead to a cold or dirty fire. Try to judge the cook length and only load as much fuel as you need with a small margin. That way you can run a small, hot fire rather than a large, cold fire.

A cold fire CAN lead to that bitter creosote taste in food that nobody likes.

Russ </div></BLOCKQUOTE>

True, and I suppose that's why it's easier to get good smoke with the water in the pan method where you start with more charcoal engaged. </div></BLOCKQUOTE>

Russ was SO RIGHT, and my turkey cook yesterday so demonstrated it! I was concerned with my first butterflied turkey getting too much smoke yesterday, so I made sure the top layer was well engaged and really hot before loading the bird on.

I stood two fist-sized seasoned chunks of pecan over the grate gaps, filled the ring with K blue bag, buried four Weber fire starter cubes in the top, and then lit with the torch. Top layer was well engaged and my bird sat with a bag of ice over the breast while the smoke quickly cleaned up after pouring my boiling water in the pan.

I only added wood once, and this has worked pretty good for me lately to get good smoke fast. I'll take one of my flatter and a little smaller chunks and simply reach in the door and wedge between the ring and bowl for a while before laying on the middle of the coals later on. Assuming it's positioned right and long enough to get hot enough, I guess the resulting quick clean smoke is like laying a split on a fire box to heat up before feeding an offset smoker. In retrospect though, I should've started with one or two more chunks and/or added another chunk. The smoke flavor was good, but it could've used a little more.

Bottom line is, Russ is 100% right in suggesting not to use anymore fuel than you'll need. I'd rather get a nice subtle, clean smoke flavor than burn my charcoal most efficiently to make sure I don't have to refuel. If I do need to at the end of a cook, that's all part of it and charcoal is cheap, anyway.

Sorry so long, but thanks to Russ for pointing out what he did. It reminded me of the other day when a fellow wsm user who's went back to using water was telling me about not having to "choke down the fire". (Of course, the hot fire will make your water evaporate fast enough to actually make a difference with what you're cooking, too.) Guess I didn't think I could even burn a clean fire on the wsm since the wood is smoldering and not flaming like on a stickburner, but it's not that simple, though! A HOT bed of coals makes all the difference! I don't care how small a chunk of wood you have on the top of your very efficient, dry pan, 12 briq lit Minion method. If the smoke smells too strong, there's a reason why.
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Just read through the post's here. I just got my new 22.5 inch WSM, did two racks of ribs and a pork shoulder at the weekend. Really pleased with it but struggled a little with the temp climbing on me. I did us the water pan. I think my main mistake was I let the temp get too high before doing anything about it. So I will do as Todd has suggested and get it to the 200 mark and then close up the bottom vents. As always it is great to read all the posts, so much information and experience. Thanks
Alan
 
Alan, don't worry about what might've been a "mistake". There is a break-in period with the bullet, and probably more so with the big bullet. As long as the fit looks good, your cooker will start settling in at more moderate temps once it's well seasoned, and you shouldn't have any more temp spike issues, maybe just the opposite, trouble getting the cooker up to temp with full loads.

I was straightening my desk and filing some stuff just the other day and noticed my notes from my first wsm cook. I cooked a couple of chickens with a dry pan, and cooked with open vents in the 300-325* range. Fast forward a bunch of cooks: last time I tried to cook dry I had to crack the door just to break the 275* mark.
 
Couldn't agree more on the "CLEAN" burning fire! If using water in the pan you can have a hotter fire with a lower cooking temp and it works..........

Try it
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Number of lit coals determines size of the fire, which determines how quickly you get up to temperature.

Vent openings determine how quickly and hot it burns.

It's really not a simple X-Y axis graph though, since the amount of unlit will determine how quickly the fire grows. It's more of a 3-D plot, if that makes sense. On top of that, there's also the water pan which acts as a buffer (heat sink) to help stabilize temperatures and slow down the rate of change.

For low/slow cooks, I'll light maybe 1/4 or less of a chimney and open 1 bottom vent [top vent always open]. Depending on outside temperature, I may use a full waterpan or clay saucer.

For a medium heat cook: 1/2 chimney and 1-2 vents open. Empty pan or clay saucer.

For high heat (350+): full chimney of lit and all vents wide open. Empty pan or saucer.

For a lengthy cook at lower temperatures or almost any high heat cook, I will make sure to start with a full load of unlit. Otherwise, I just use whatever leftovers are in there or maybe add a few more.

I hope that helps.
 
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Jon Des.:
Number of lit coals determines size of the fire, which determines how quickly you get up to temperature.

Vent openings determine how quickly and hot it burns.

It's really not a simple X-Y axis graph though, since the amount of unlit will determine how quickly the fire grows. It's more of a 3-D plot, if that makes sense. On top of that, there's also the water pan which acts as a buffer (heat sink) to help stabilize temperatures and slow down the rate of change.

For low/slow cooks, I'll light maybe 1/4 or less of a chimney and open 1 bottom vent [top vent always open]. Depending on outside temperature, I may use a full waterpan or clay saucer.

For a medium heat cook: 1/2 chimney and 1-2 vents open. Empty pan or clay saucer.

For high heat (350+): full chimney of lit and all vents wide open. Empty pan or saucer.

For a lengthy cook at lower temperatures or almost any high heat cook, I will make sure to start with a full load of unlit. Otherwise, I just use whatever leftovers are in there or maybe add a few more.

I hope that helps. </div></BLOCKQUOTE>

John - thanks. I seems like its important to have coals burning efficiently. Fewer coals burning hot are better than more coals burning cooler. I do however have the same concern that you bring up. The rate that the fire spreads to the unlit coals. Can you keep a small 12 coal fire going and spreading in a controlled manner to the adjacent coals by choking down the vents? It sounds like if you choke down the vents before the fire gets too hot then you can keep a small fire under control.
 
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Jeff B:
John - thanks. I seems like its important to have coals burning efficiently. Fewer coals burning hot are better than more coals burning cooler. I do however have the same concern that you bring up. The rate that the fire spreads to the unlit coals. Can you keep a small 12 coal fire going and spreading in a controlled manner to the adjacent coals by choking down the vents? It sounds like if you choke down the vents before the fire gets too hot then you can keep a small fire under control. </div></BLOCKQUOTE>

I guess the whole point of my rambling post last night is that it's a lot easier to get a stable fire at a specific temperature if you build your fire for it, rather than trying to get there from an incorrect set-up.

Choking the vents will go a long way to controlling the spread of the fire, but it also helps to plan ahead for the time and temperature you need. In my opinion, in order to control the spread of the fire using the Minion Method, you need to distribute the lit coals so that the fire spreads slowly as the lit coals turn to ash. For example, if you dig through this post you'll see a set-up that I used for a lengthy low heat cook with maybe 6-10 coals burning the whole time. The firebrick limited the direction the fire could travel so it basically went counter-clockwise around the coal bin. I think some guys will pour unlit coals around a coffee can or something similar so that the lit can be added in a pile where the can was and burn out evenly from there. On the other hand, if I'm doing a high heat pulled pork or something along those lines, I'll fill up the coal chamber as much as I can and then just dump a chimney of lit right on top.

It's really not rocket surgery, but I think these are little tips that maybe don't get mentioned very often. I had a lot of experience cooking on a kettle before my WSM, but I still had some very unexpected temperatures and major swings during my first few cooks. The WSM isn't instaneously responsive like a gas grill, but with some practice and a little forethought into what type of fire you need, you'll get the hang of it in no time.
 
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