Evenness of Indirect Area with SNS

[jfmorris]

I was responding to another topic, and it popped into my head that I feel I read *somewhere* that the temps in the indirect area of the kettle when using the SNS can be a little hotter at the far edge, AWAY from the SNS insert, due to convection currents.

Can anyone comment on this? If not, maybe we need one of our brethren with a SNS, a Fireboard and 6 temp probes to conduct an experiment or two with the SNS and report back on how even temps are with the lid on, in an indirect setup for 225 with water in the SNS, and in an indirect 350F setup without water for chicken...

I could test here, but would have to use multiple thermometers to get the job done, so would not have a fancy graph with all probes on it...

Kinda feeling someone here has already looked into this, probably during the development of the SNS...

[hoovarmin]

I don't have any data, but I have always felt this to be the case.

[DaveD]

You do now

[Rod]

I too believe that to be the case as well. I run 225 by lighting one end of the SnS. I wonder how that affects the edges furthest away from the SnS as the hot coals travel from one end to the other? For 350, everything is more uniformly hot across the SnS from start to finish.

[bmillin]

Maybe time for a biscuit test. I volunteer, not enough probes on hand for the fireboard test.

[Huskee]

When testing this is what I found. I put a full packer brisket in my 22' kettle (it *just* fit) and the edges were darker. I don't have specifics any longer, but I did at one point.

Also the temp rises drastically the more upward you go, but that's probably obvious.

[Clark]

Huskee Not sure what you mean by "more upward you go".

[vkashmoney]

Clark He means that the higher the meat sits within the grill, the higher the temp it will exhibit and the faster it would cook, since hot air rises. See DaveD's comment a few down, where he placed temp probes both above and below the grill grate, and the temp probes below the grate consistently read 20-25F lower than the temp probes above the grate.

[Clark]

vkashmoney Thanks!

[WayneT]

I have always been pleasantly surprised by how well my SNS holds temp using my FB2 with the probe toward the back of the indirect cooking area. The dome thermometer runs pretty close also. Let’s tag ecowper on this since he’s done a lot of trial and error on his SNS.

[Johnny Booth]

Same on my PK360, which has a dome lid. The convection hits the dome and travels down the opposite side 1st. I learned this when spatchcocking chickens. I noticed the side (breast and thigh) away from the coals was consistently browning faster.

[ecowper]

There is definitely a temp difference from the part of the indirect zone nearest the water tray to the outer edge at the front handle. I haven't measured it with multiple probes like I've done with the Hasty-Bake. I should probably do that. What I can tell you is that when you are cooking chicken, this will become apparent to you pretty quickly :-)

[Smoker_Boy]

ecowper - We think you should do this.

For science.

[jfmorris]

Yeah - I notice in some videos or photos on the SNS site when doing a turkey on the kettle with the SNS, they pointed the legs AWAY from the fire, which seems counterintuitive at first, but makes sense with the convection thing going on.

[58limited]

I have measured temps on my SnS Kamado and temps are higher at the outside edge - by about 10 degrees if I recall, maybe more. Also there is about a 3-5 degree difference from front to back on mine.

[DaveD]

A month or two after I set up my SnS, I did a calibration experiment aimed at understanding the difference between probe temps if the probes were clipped above or below grate level, following some discussion with experienced SnSers here. As you can see, there is a quite significant and consistent difference. (I was hoping I could clip underneath to not take up any space up top. Answer: Nope! You'll be cooking at least 25F hotter than you think you are.)





I'm definitely set up to do this experiment and once the weather allows, I'm yer guy for this one Please describe just where you'd like the probes to be, and I'll git 'er done. For SCIENCE.

[Smoker_Boy]

DaveD - You Da Man.

[vkashmoney]

DaveD This is awesome, thanks for sharing!

[ecowper]

I’m thinking I will do a 1 hour low and slow on the SnS on Sunday specifically to run all my probes in different spots and figure out the temps and convection.

I’m completely unsurprised that under the grate is much cooler. That water mass is going to block a lot of heat

[Smoker_Boy]

Maybe something like this:

SNS is @ 90 degrees

So, 1 probe tip at the major diameters of 180, 270 and 0 degrees.
Then the remaining 3 at the smaller circle diameter also at 180, 270 and 0 degrees.

In theory, the 2 closest to where the fire starts should be the highest and the others lower.
(assuming you start the coals at 0 degrees)
As the fire moves towards the left, the highest temps should follow.

Does this make sense to everybody??

EDIT - Try to clarify circle

[DogFaced PonySoldier]

I don't have a SnS.... yet. But I do have a Fireboard and a Weber. Might just have to do this experiment myself, as well...

[Smoker_Boy]

DogFaced PonySoldier - I just got my new 4 probe replacement meter, so I'll now have 7 probes total. I won't have the fancy graph, but I'll get some good data.

Just think, boys and girls - we just might learn something.
(but we also won't have any excuses in the future)

[DaveD]

Makes total sense, I see exactly what you're after. No problem. For no particular reason, I start my burn on the left rather than the right, but that doesn't matter.

I'm thinking I might modify the placement a bit if it's OK with you, like so:



I think it would be more informative to have the outer perimeter with more coverage, instead of four measurements along that horizontal line, i.e. moving three of the original positions as indicated in red. That would give three probes along the horizontal instead of four, and five along the perimeter instead of three. It would sacrifice the one smack in the middle though. So maybe I'll leave one smack in the middle and distribute four along the outer perimeter... they would be at 180, 240, 300, and 360 (shown in cyan), and the one in the middle of the indirect zone would stay where you have it. Would that work for you? I do think we'd get better indication of cooking conditions that way.

Now just have to get a good day to do this! Looking at the forecast, the earliest I could do it would be Friday 2 Feb (I plan on taking that day off), which is currently forecast to be dry with seasonable temps, with a high just under 50F/10C coming off a low just above freezing. Really looking forward to this!

[Smoker_Boy]

DaveD - That's totally fine with me. Thanks for your offer!

[Skinsfan1311]

Interesting topic.

I've used an SnS since they came out and never noticed, (or looked for), a temp difference. While it remains a fixture in one of my kettles, I don't use it for low and slow cooks anymore. The WSM & Kamado have taken over those duties. Most of my cooks are quick and hot grilling or reverse sears and I don't use the water pan in either.

That being said....next time I fire it up, I'll try to remember to stick a few probes at grate level in different locations to see what the differences are.

Somewhat unrelated, I do notice that the lid thermometer reads 70deg higher than the temp at the grate and has been consistently like since I first bought the SnS...maybe 8-9 years ago?

[DaveD]

Are you using the insert in a Weber kettle, or the SnS kettle itself? On the latter, the lid thermometer is placed much closer to the grate than on a Weber and in my experience thus far, is within 10-20F of what I'm reading on the grate. Best performance I've seen of any cooker's built-in thermo (but I have owned far fewer cookers than many here).

[Skinsfan1311]

DaveD Weber.