# Water versus Sand in the WSM?



## engineer68 (Sep 17, 2015)

I have a 18.5" WSM and was wondering...if I put sand in my water dish will I run the risk of drying out my pork butts? Especially big ones running around 14 to 16 hours. I got the impression that the water helped keep the cooking environment moist to prevent drying out the meat especially since I don't foil wrap through the stall.


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## bama bbq (Sep 17, 2015)

No.  A pork butt has so much fat it will not dry out even with a dry pan which is what I use.


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## joe black (Sep 17, 2015)

When I had a WSM, I used water for a few times, then switched to  sand and finally to a clay saucer.  Then, I threw the saucer away and cooked naked until I sold it several years later.  I don't think anything makes a difference in a WSM.  They are so user friendly, I don't think you can hardly go wrong.  Good luck,  Joe


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## oldschoolbbq (Sep 18, 2015)

I feel that water (as a heat 'baffle'  )  keeps your temps. to a lower degree (water boils at 212*F ) , this is why a dry sand (or a clay plate) is a better choice ! 

I have an offset 'Dragon' , and have baffles in it for my heat protection !

Just my 2 cents opinion :biggrin:

Have fun and . . .


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## brazosbrian (Sep 18, 2015)

Water absorbs energy and converts the water to 212F water vapor ...and both this energy absorption and the injection of 212F water vapor, counters temperatures that are higher than 212F... the reason for the water.  It is to help maintain a stable _low _temperature for low and slow cooking.  THAT said, the general experience in this particular user audience is that this isn't really necessary in the WSM.  Using sand (or bricks or whatever) instead does not counter higher temperatures, _but _as a thermal mass that either absorbs or releases energy, does act as a stabilizing thermal mass.  In other words, non-water thermal masses will help prevent dips and spikes in the temperature in your cooker, but will not regulate the temperature (down) for you if you've got your vents too open for the lower temperature that you are trying to cook at.  With a non-water thermal mass and properly set vents that keep the temperature low, the cooking works just fine.  The last, and only, advantage to water is that it helps keep the atmosphere in the cooker more moist ..._theoretically _helping to prevent water loss from what you are cooking.  The jury is still out on whether it really helps or not, and the circumstantial evidence among the users here suggests that meat will stay moist without having to have water vapor injected into the cooker.  The bottom line is that you can use water, or sand (etc), as your thermal mass and that it's up to you to set up those vents to maintain your target temperature.  And obviously, if you want to cook hotter, say at 350F+ for chicken, you should avoid water since it 'tries' to pull the temperature back down, resulting in having to burn more charcoal to try to get the temperature as high as desired.

Brian


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## katman (Sep 18, 2015)

As said above, the water, sand, saucer (whatever) will keep the temps lower.  I use a clay saucer covered in foil for easy cleanup.


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## joe black (Sep 18, 2015)

Now I know where to get the research material for my Doctoral Thesis in "The Physics of a Stabilized Thermal Mass within a Heated Environment".  LOL.  Thanks Brian


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## dward51 (Sep 18, 2015)

I use a clay saucer I bought at Walmart.  The WSM runs longer than with water on the same load of charcoal using the saucer.


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## b-one (Sep 18, 2015)

I just use the water bowl lined with foil.


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## ivanstein (Sep 19, 2015)

I did a write up in the thread about the WSM using lots of charcoal. It has a lot of the same thoughts presented here.

I do have to contradict the water vapor and moisture theory though. I will cite Alton Brown here. The "moisture" in BBQ is actually rendered fat and collagen which coat the meat fibers and give the mouth feel of moisture. We pull pork butts and briskets at internal temps close enough to the boiling point of water (higher depending on altitude and atmospheric conditions) that most all water in the meat will have "boiled out".

Now, the benefit of moist air is that water carries heat better than air. So moist air will transfer more BTUs per minute than dry air of the same temp. So, cooking at 200° in moist air will transfer as much heat as, say 220° in dry air. Lots of variables here, just look up a thermodynamics book! But this is the general gist.


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## lyricalchaos (Sep 21, 2015)

I used the water when I first started, but hated having to deal with the mess when cleaning it out. I now just use the pan covered in foil with no sand or saucer. It doesn't need it, it still provides indirect heat as a barrier between the charcoal and whatever you are cooking. It also allows me to go easily from low heat to high heat depending on what I'm cooking. I am able to control temp with vent use and maintain easily for anything from hamburgers to pork butt. You just learn where to dial in charcoal amount and vents depending on what you are cooking.


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## larosa94x (Sep 21, 2015)

I know this is about a WSM but I think your question is more or less "will using sand v. Water dry out my shoulder" and to answer that- I just did my first butt which took 17 hours and I used sand and the butts literally fell apart in my hand as I was removing it from the grates..
So no I don't think you have to worry about them drying up.


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## dward51 (Sep 21, 2015)

I should have added that I put the foil covered saucer base in my water pan which is also foiled.  The water pan keeps the direct flames & heat off the saucer.  I think it might crack otherwise, and it's harder to find a saucer to fit the water pan tabs directly (without the pan in).  This way the foiled saucer sits in the top of the water pan so size is less critical.


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## brazosbrian (Sep 22, 2015)

I want to add a couple more water versus sand (or other dry thermal mass) to the discussion:

Since water vapor counteracts temperatures above 212 F, you can get away with running your cooker with the vents wider open ...more forgiving and/or helpful if your charcoal doesn't burn well with very low venting.  That's the good thing.  But if your charcoal _does_ burn well with low vent settings, then you will use less of it if you use a dry thermal mass ...saving you some money on charcoal and still getting the job done.

Brian


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## drewed (Sep 22, 2015)

I run the big WSM, and if you are going to use sand, don't fill the water dish full.  That is way to much sand and really sucks to try and lift out.  You don't need that much thermal mass.  
I can see a plus to running water in that steam looks like smoke and could help keep you from over smoking your meat!  Yeah, I've done it....  Billowing clouds looks cool, but tastes like yuck!


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## valleypoboy (Sep 22, 2015)

Water I understand. Sand and clay I dont. Brian, you did a great job of explaining it but why not use something with good thermal conductivity that will absorb the heat then retain it like a big chunk of iron or steel? Sand and clay are terrible thermal conductors. Aluminum is great but will heat up and cool down too fast (imo), copper is excellent, but even faster and expensive. Cold rolled steel is pretty cheap and would work great imho.


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## engineer68 (Sep 22, 2015)

Thank you all!!!

I don't think I could have learned more in a shorter period of time by any other method than this forum and those of you who contribute to it. I will be trying the sand method from a thermodynamics and also from a clean up point of view. Yes cleaning and re-foiling the water pan is messy and time consuming and I am also anxious to see the fuel consumption drop with accurate vent management. 

Much appreciated advise.


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## brazosbrian (Sep 22, 2015)

valleypoboy said:


> Water I understand. Sand and clay I dont. Brian, you did a great job of explaining it but why not use something with good thermal conductivity that will absorb the heat then retain it like a big chunk of iron or steel? Sand and clay are terrible thermal conductors. Aluminum is great but will heat up and cool down too fast (imo), copper is excellent, but even faster and expensive. Cold rolled steel is pretty cheap and would work great imho.


I think you make a good point.  Higher heat conductivity is better.  If, for example, your (very conductive) thermal mass is not working very well at dampening the peaks and valleys in temperature, then it just needs to be _bigger_.  Hmmm... someone ought to do a side-by-side comparison of brick (or sand or clay) versus a big chunk of iron.  Of course, the iron is likely a lot heavier ...hopefully not enough to tweak the legs on the cooker 
	

	
	
		
		



		
			






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## valleypoboy (Sep 23, 2015)

It would have to have pretty flimsy legs. I'd think a 10 to 30lb pan or plate would do the trick.


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## bobcats110 (Sep 23, 2015)

Is this talk of sand and thermal conductors new?  I'm actually sitting at my desk thinking you've all split the atom again or something.  Learned more in the last five minutes about my WSM and a new way to use it, so thank you.

I get the explanation that Brian gives and understand the theory, and if you take the experiences here that NOT using water DOESN'T result in dry meat, then awesome - I hated the water clean up myself.

My question now is - What kind of sand are we talking about?  White Beach, Sandbox that you can buy at Home Depot, etc., etc.

Thanks for a great thread,  friends in smoke.....


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## drewed (Sep 23, 2015)

valleypoboy said:


> Water I understand. Sand and clay I dont. Brian, you did a great job of explaining it but why not use something with good thermal conductivity that will absorb the heat then retain it like a big chunk of iron or steel? Sand and clay are terrible thermal conductors. Aluminum is great but will heat up and cool down too fast (imo), copper is excellent, but even faster and expensive. Cold rolled steel is pretty cheap and would work great imho.


You don't want a good thermal conductor, you actually want a poor conductor.  The idea behind the sand or clay pot or pizza stone or big rock is that it will absorb the higher temps ( by taking time to heat up ) and release that stored heat back to the smoker as the fire starts to die, or there is a wind gust or something.  Think of it as more of a temperature shock absorber.  Metal would give the heat off too quickly, unless you are going to go for a huge amount of cast iron, but then the sand is cheaper.


bobcats110 said:


> Is this talk of sand and thermal conductors new?  I'm actually sitting at my desk thinking you've all split the atom again or something.  Learned more in the last five minutes about my WSM and a new way to use it, so thank you.
> 
> I get the explanation that Brian gives and understand the theory, and if you take the experiences here that NOT using water DOESN'T result in dry meat, then awesome - I hated the water clean up myself.
> 
> ...


yeah, any clean sand.  I got a bag a play sand form homer depot for a couple of bucks.


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## brazosbrian (Sep 23, 2015)

Hmmm... not sure I can agree with the suggestion that using a porous thermal mass _inside _the cooker is better than one that is highly conductive (of heat).  Consider, for example, that the thermal mass is entirely contained inside the cooker and that any energy that it absorbs or releases is within the cooker as well.  As the temperature in the cooker goes up (spike in charcoal temperature), you want the thermal mass to 'react' quickly, by absorbing that heat.  If the spike in temperature ends and the cooker starts to cool, then you want the thermal mass to release the energy back into the chamber quickly as well.  Porous materials such as clay, sand, or concrete are noted for use where their heat insulation capabilities are important ...like an adobe house that is cool during the day in spite of the rising temperature of the hot sun outside the house.  In that case, you are trying to prevent the temperature differential on opposite sides of the adobe from conducting through the material.  With a BBQ, something like a ceramic or clay BBQ body would help maintain a consistent temperature inside the cooker by preventing sun/wind/rain from conducting heat into/out of the cooker, but a highly conductive mass (say, iron) that is inside the cooker stabilizes the temperature inside the cooker by easily absorbing spikes in energy/heat and easily giving out energy/heat when the inside of the cooker cools - a stabilizing element.  This is why The Big Green Egg (and similar) are made from clay, but no manufacturer of BBQs suggests using sand or clay or bricks inside the cooker ...instead preferring water, both because it conducts heat more easily and also has that 212 F state conversion (liquid to vapor) constant that makes the BBQ more forgiving of too-open vents.

Here's some thermal conductivity numbers, followed by an experiment that someone with a remote thermometer should try (source: http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html):

Air                                 0.024

Insulating Brick               0.15

Dry Sand                        0.15 - 0.25

Water                             0.58

Building Brick                  0.60 - 1.0

Granite                            1.7 - 4.0

Iron                                80

An experiment (hopefully in a somewhat controlled environment, e.g. same outside temperature and no wind or rain):

1. Empty bowl (the 'Air' test) - run BBQ at say 250 F and stabilize for 15 minutes, then open vents fully and monitor temperature every 30 seconds (or 1 minute).

2. Bowl of water (weighed), steaming/simmering (water plus state change test) - run BBQ at say 250 F so it is stable for at least 15 minutes (water must be steaming/changing liquid to vapor), then open vents fully and monitor temperature as above.

3. Repeat with same weight in dry sand as water, same procedure as in #1

4. Repeat with same weight in iron, same procedure as in #1

_Not _perfectly scientific, but the range in thermal conductivities is wide enough to at least illustrate a pattern.  The best temperature damper will show the slowest response to opening the vents.  Maybe some weekend, I will try this?

Brian


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## larosa94x (Sep 25, 2015)

I believe the Columbians during the big cocaine trade used to take big slabs of granite with a fire underneath it to make pretty much a flat top grill to heat up the Coke if it got wet during transport.

I wonder how granite would do inside the pit. The only problem I see with granite is it's extremely heavy and I feel like it would crack over time.


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## brazosbrian (Sep 25, 2015)

I'll bet you can get surplus chunks of granite from your local tombstone maker.  In a prior life, we used to have custom slabs cut at the local tombstone maker for use in high-speed manufacturing to stabilized machines with fast-moving robotics in them.  There were always chunks of granite in odd shapes laying around the tombstone shop... I updated my post above to include the thermal conductivity of granite ...it's good stuff!

Brian


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## dwhite1031 (Sep 25, 2015)

So is the pan of sand acting like a heat sink does in electronics?


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## rich t (Jan 30, 2016)

bobcats110 said:


> Is this talk of sand and thermal conductors new?  I'm actually sitting at my desk thinking you've all split the atom again or something.  Learned more in the last five minutes about my WSM and a new way to use it, so thank you.
> 
> I get the explanation that Brian gives and understand the theory, and if you take the experiences here that NOT using water DOESN'T result in dry meat, then awesome - I hated the water clean up myself.
> 
> ...


Amen!


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