Question on Heat Sinks


 
Roger R.

Roger R.

TVWBB Fan
I have always filled my water bowl with clean sand, and placed a foil wrapped terra cotta tray on top of the sand bowl. It has always worked well for me - except that it is bloody heavy when moving the mid section on my 18.5" WSM. Once I got out of balance and the sand bowl actually slipped off the hangers. By & large it has been a perfect heat sink.

Lately I have removed most of the sand, leaving about 1" in the bottom of the bowl, then placing the tin lined terra cotta tray on top of the bowl. It seemed to work just fine. Does anybody have experience with this method? Is 1" of sand enough? It sure makes moving the mid section off & on a breeze.

Your comments are appreciated.
 
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When I use my bowl, I just have the terra cotta in the bowl (stops about 2" from the top of the bowl) and I cover it with foil. That's my set up when I want to run 250 degrees or less. Most my cooks these days are simply an old pizza disk sitting on the bottom rack of my WSM
 
You don't need a heat sink. It does not add anything but stability. It just sucks up heat if the heat goes above the temp of your heat sink, and gives off heat if it goes below. It makes temperature swings slower.

If your temps are stable you don't need more.
I often don't deal with wind, and have no trouble keeping temps with in a degree or so with nothing added as a heat sink, just the empty bowl wrapped in foil to block direct heat and catch drippings.

Water is used to keep temp down, as it wont heat up to above 212-ish. Once it gets to boiling, it boils at a constant temperature and instead of heating that energy is used to turn water from liquid to steam, which takes way more energy than heating water or air. It also adds humidity which helps to minimize evaporative cooling of the meat (where the meat lose temp as it sweats) and aid helps smoke adhere to the meat.
 
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Sean,
Wouldn't an empty water bowl (metal) heat up - without sand in it?
All these years I've thought that the sand filled bowl would deflect heat around the sides, but not absorb much heat - to transfer. Hence my question regarding using only 1" of sand plus the clay tray.
 
Hi Roger, I use water so I'm not really interested in this topic, however regarding sand heating up have you ever walked in sand on the beach in the middle of a sunny day? (great heat retention)
 
Roger R. said:
Sean,
Wouldn't an empty water bowl (metal) heat up - without sand in it?
All these years I've thought that the sand filled bowl would deflect heat around the sides, but not absorb much heat - to transfer. Hence my question regarding using only 1" of sand plus the clay tray.
Click to expand...

A water bowl with sand in it will heat up too. Just not as fast. Maybe with a lot, it will still be rising in temp until the end of the cook... But being directly over the flame I am guessing its gonna get up to a stable temp in an hour or so? Really probably less? Guess its gonna depend on the sand really...

But if you fill the bottom of a kettle with lit coal, then put a pizza stone over it... its going to get the top of the stone pretty dang hot too yes? Its going to heat the bottom of the stone until its as hot as the air directly above the coals then that heat is going to keep soaking through the stone until the top is hot too. Eventually the top of the stone will rise above the temp of the air in the cooking area, and it will start losing heat to that area... But at that point some of the heat is flowing through your heat shield.

If your heat shield has more thermal mass, it will soak up more energy... but it will still soak up energy, and that will still raise its temp, and that temp rise will eventually make it to the other side of that material, where the hot material will heat the air, and the cooler air will cool the material... So once its soaked you will still see a similar flow of energy through the barrier... Its just that it will have enough mass that it wont change temps as rapidly... So if fire temp drops it will still have plenty of heat to give off, and if fire temp rises, it will be able to soak up a little more without letting the cook temp rise too much.

But grab an IR thermometer, and measure the temp of the top surface of your heat shield. Unless its equal to or less then the temp of the air in the cooking chamber, and rising in temp through out the entire length of the cook, your seeing the top surface giving off heat to the cook chamber... Your really just helping to even things out.
 
Here's an old article from 2003 when in used a data logger therm to measure temps in the WSM using an empty pan, water in the pan, and sand in the pan. Not huge differences in performance: WSM Temperature Tests

After my years of WSM experience, I don't think about heat sinks anymore in the WSM. I think of water as something that can be used to make temp control easier for beginners and something that adds moisture to the cooking environment to enhance smoke flavor and smoke ring. Otherwise I use an empty water pan with nothing in it. No sand, pizza stone, steel plate, terra cotta saucer, etc.
 
Chris Allingham said:
Here's an old article from 2003 when in used a data logger therm to measure temps in the WSM using an empty pan, water in the pan, and sand in the pan. Not huge differences in performance: WSM Temperature Tests

After my years of WSM experience, I don't think about heat sinks anymore in the WSM. I think of water as something that can be used to make temp control easier for beginners and something that adds moisture to the cooking environment to enhance smoke flavor and smoke ring. Otherwise I use an empty water pan with nothing in it. No sand, pizza stone, steel plate, terra cotta saucer, etc.
Click to expand...

I agree with Chris. I use water on long cooks to keep a moist cooking environment and believe it helps the meat absorb smoke and increase smoke ring.
 
I'm a total newbie to all of this, but I've done quite a bit of reading here, and decided a foiled empty pan was the way to go.

First cook was sausages with the foiled empty pan. It was only about an hour, but the temperature was pretty easy to control with just the vents.

Second cook was chicken, and after reading here it seemed high heat was the way to go, so used no pan at all. So, that doesn't count in this context.

Third cook was pork butt with a foiled empty pan. The cook was 11 hours and the temperature stayed 225-250 (lid thermometer) almost the entire time, just just slight adjustments to the bottom vents. There were only maybe 2-3 times where the temp went much below 225 or above 250, and they were easily fixed with a vent adjustment. I was only checking the temp about once per hour.

I know that was just one long cook, but I think I'll stick with a foiled empty pan.

Now, if I were trying to keep temps closer to 200, I might see the appeal of putting water in the pan, but at the moment, I don't plan to be cooking anything that low.
 
Andy Erickson said:
For those that don't use water in the pan, ever have any bad tastes from the drippings burning in the pan?
Click to expand...
Andy, I think most of us foil the pan, leaving air space between the foil and bottom of the pan.
I've never had the drippings burn with that method.
 
I have been putting two sheets of foil across the top of the pan, in a plus (+) shape, leaving a little slack so it dips down a little. So, I have the entire volume of the pan between the foil on top and the bottom of the pan, if that makes sense. I don't remember if I foiled the inside of the pan (I think I did), but the drippings land on the foil sheets running across the top.

I also foil the whole bottom of the pan.
 
Jason Paul said:
I have been putting two sheets of foil across the top of the pan, in a plus (+) shape, leaving a little slack so it dips down a little. So, I have the entire volume of the pan between the foil on top and the bottom of the pan, if that makes sense. I don't remember if I foiled the inside of the pan (I think I did), but the drippings land on the foil sheets running across the top.

I also foil the whole bottom of the pan.
Click to expand...

I do the same, but I'm thinking lately that foiling the under side of the pan doesn't really do anything except keeping the bottom of the water pan from getting sooty. In that sense, as long as you don't go putting the water pan down somewhere you shouldn't (say, on a basket full of clean laundry or a tablecloth), it seems like a waste of foil.
 
Chris Allingham said:
Here's an old article from 2003 when in used a data logger therm to measure temps in the WSM using an empty pan, water in the pan, and sand in the pan. Not huge differences in performance: WSM Temperature Tests

After my years of WSM experience, I don't think about heat sinks anymore in the WSM. I think of water as something that can be used to make temp control easier for beginners and something that adds moisture to the cooking environment to enhance smoke flavor and smoke ring. Otherwise I use an empty water pan with nothing in it. No sand, pizza stone, steel plate, terra cotta saucer, etc.
Click to expand...

Couldn't one simply spritz every 15 mins after the bark forms to achieve the same?

Thoughts?
 
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Mac LA said:
Couldn't one simply spritz every 15 mins after the bark forms to achieve the same?

Thoughts?
Click to expand...

to some degree, especially wrt to moisture on the outside of food helping smoke particle to adhere long enough to be absorbed into the meat. The main difference I would anticipate is that having higher humidity in the air due to a water pan would slow down evaporative cooling of the meat, while simply spritzing would mean the air in the cooking chamber would be drier which would cause more evaporation and more cooling of the meat. So your spritzing would likely evaporate sooner (how much?) and cause a little more cooling (how much?) which combined with constantly opening to spritz would likely lengthen cook times.

However, if your trying to get more smoke absorption perhaps that could even help?


In favor of a water pan:
IMO, when I use no water I have to cut the vents down a lot, which means choking the fire more.

From amazingribs
http://amazingribs.com/tips_and_technique/zen_of_wood.html
"In the sweet spot of about 650 to 750°F, the best aromatic compounds for cooking come off, among them guaiacol and syringol"
Numbers I have read in other sources as well, such as Aaron Franklin's book. Secondary combustion of wood (a standing flame) occurs ~700
Perhaps this is where people often like stick burners more, and why methods like the snake and minion are more popular.

As Meathead points out:
"Build a small hot fire. You want to see flame. Fires burning in the 650 to 750°F range in the hot spots burn off the impurities that can be created in an incomplete secondary combustion. That means that you need a lot of oxygen so you want your exhaust vent open all the way. The hot air rising through the chimney will draw in air through the intake vent. You will probably want it open wide or close to it. Low smoldering wood creates dirty smoke."

I have definitely noticed on my 14.5 at least, that it is difficult to get enough air in, while keeping cooking temperatures down and not having to choke the coal's air. You want a smaller fire, near bursting into flames rather than a big pile of smoldering coal.

Having a water pan can help suck energy out of the air to lower its temperature while allowing more complete combustion of your coals, at least according to theory... so I have gone back to using it.
 
I use a version of the Piedmont Pan: two pans put together with an air space between them, and foil inside the top pan for easy cleanup. The drippings don't get hot enough to burn. No sand, no extra weight.
 
This is one of those never-ending debates similar to using UV/Haze filters on cameras lenses. No wrong or right answer of than YMMV and past performance is not and indicator of future results. I used both water and a foil lined 16" clay saucer inside a foil wrapped water bowl. I really could not tell the difference between water and the clay saucer but I continue to use the saucer because it is less worry and so much easier to cleanup. Once the meat hits the rack and the dome is set in place, it stays on until my ET-732 hits the target temp range to begin cooking to tenderness. Dealing with 1-2 qts of grease water in my subdivision is a major pita. I won't flush it down the drain and can't throw it in the yard because it will attract vermin, pets and rodents. I have thrown the grease water in a trash bag full of old newspaper and pitched but once the bowl is cool to touch, I unwrap the bowl and throw the waste in the trash. Easier.
 
Sean R said:
to some degree, especially wrt to moisture on the outside of food helping smoke particle to adhere long enough to be absorbed into the meat. The main difference I would anticipate is that having higher humidity in the air due to a water pan would slow down evaporative cooling of the meat, while simply spritzing would mean the air in the cooking chamber would be drier which would cause more evaporation and more cooling of the meat. So your spritzing would likely evaporate sooner (how much?) and cause a little more cooling (how much?) which combined with constantly opening to spritz would likely lengthen cook times.

However, if your trying to get more smoke absorption perhaps that could even help?


In favor of a water pan:
IMO, when I use no water I have to cut the vents down a lot, which means choking the fire more.

From amazingribs
http://amazingribs.com/tips_and_technique/zen_of_wood.html
"In the sweet spot of about 650 to 750°F, the best aromatic compounds for cooking come off, among them guaiacol and syringol"
Numbers I have read in other sources as well, such as Aaron Franklin's book. Secondary combustion of wood (a standing flame) occurs ~700
Perhaps this is where people often like stick burners more, and why methods like the snake and minion are more popular.

As Meathead points out:
"Build a small hot fire. You want to see flame. Fires burning in the 650 to 750°F range in the hot spots burn off the impurities that can be created in an incomplete secondary combustion. That means that you need a lot of oxygen so you want your exhaust vent open all the way. The hot air rising through the chimney will draw in air through the intake vent. You will probably want it open wide or close to it. Low smoldering wood creates dirty smoke."

I have definitely noticed on my 14.5 at least, that it is difficult to get enough air in, while keeping cooking temperatures down and not having to choke the coal's air. You want a smaller fire, near bursting into flames rather than a big pile of smoldering coal.

Having a water pan can help suck energy out of the air to lower its temperature while allowing more complete combustion of your coals, at least according to theory... so I have gone back to using it.
Click to expand...

Thanks, your posts are always an interesting read.

I have a feeling I may end up with a stick burner sooner rather than later. I very much enjoy heavier smoker profile, but than again, I haven't done any meat on the this unit yet.

With regards to not having suffice air circulating, have you considered an automatic temp regulator, such as an IQ or Auberins, would that even help?

I'm going to try the way I was taught first, (without water) then give some water a run.
 
Johnny,

Just having a stick burner does not in itself improve the quality of the cook. There's so much more to it. If that was the case, you would never see WSMs at professional BBQ contests where cooks are vying for thousands of dollars in award monies.

One can create Exceptional BBQ on a little 'ol WSM. If you want to see how it's done, come on down to a local BBQ contest this year. Great learning experience as well as a heck of a lot of fun.
 
Mac LA said:
Thanks, your posts are always an interesting read.

I have a feeling I may end up with a stick burner sooner rather than later. I very much enjoy heavier smoker profile, but than again, I haven't done any meat on the this unit yet.

With regards to not having suffice air circulating, have you considered an automatic temp regulator, such as an IQ or Auberins, would that even help?

I'm going to try the way I was taught first, (without water) then give some water a run.
Click to expand...
Experiment, but I wouldn't totally give up on experiance like you said. Some of this is nuance.
It may be better to be good at being close enough then bad at theory :p

I am still learning this too, and am still getting everything down, but I do have an engineering degree and I do read too much, and I did grow up playing with fires, lol

As Bob points out, plenty of people doing more then well enough with the WSM... Perhaps I need to get my minion method down, however it seems like no matter how small a fire I start If I give it the oxygen to burn well with no water the temp ramps up as the fire grows. I do always buy lump, and that may be part of it.

As far as the temperature control.... to my understanding its just regulating air. I can do that plenty with vents so I don't think it would help. Id love to experiment with a maze similar to what is used for cold smoking though to make a snake with the same amount of fuel as it normally holds. This may also be more of a problem with the 14.5 as it is so much smaller and you still have a pile of burning coal in the bottom, just heating less volume and making it hotter.
 
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