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UDS temperatures?

Desertracer

Knows what a fatty is.
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I just got done with my first cook on my UDS and have a question about my temp readings.
I bought the Big Poppa UDS kit that comes with the mounted side temp gauge and i also got a Maverick ET-732 temp gauge. I smoked ribs for my first cook at 275 degrees consistintly according to the Maverick but the side temp gauge was off 40-50 degrees lower. The Maverick probe was place in the center of the grate. I smoked the ribs uncovered for 2 1/2 hours and the wrapped for an additional 1 1/2 hours.
The ribs did not come out as tender as i would like and was wondering if the Maverick temp was off a little? I also built my fire basket with 15 lit coals and placed them in the center of the basket. Should i have just spread them out over the top to get a more even heat throughout the barrel?

Any comments would be helpful.
 
All UdS's will be 40-50 deg hotter in the center. I use 8-10 briquettes I light mine and I put them close together in a circle around the circumference.
 
I'm not surprised in the least. Your fire basket is smaller than the drum. With that design the outside edge is always going to be a bit cooler than the center.

That is why many UDS people have a ~8-10" deep fry candy thermometer mounted on the side of their drum. You get a better idea of what the temps are like in the center that way.

You could add a third rack with a platesetter (ala egg). Pizza pan, terracota saucer etc. That will even out the temps a bit.

It was one of the first things I noticed on the poppa kit. Short thermo. Look on the bright side, you can brag that your drum cooks up everything faster.:thumb:
 
I decided to do some chicken today using a deflector and right away I can tell the temp is a lot more consistent. The cook is still on-going...i will let you know how it turns out...hopefully with some pron! Thanks for all the good info.
 
The temps on both temp gauges were right on with the deflector and it appeared the meat got consistent heat this time. Here is my chicken pron...thanks
 

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I get pretty even heat in mine, but then I have a fire door built into the side and all I do is hit it with the weed burner and place the deflector on top of the basket. I had my deflector made from the lid of the drum. There is a simple rebar hoop on it for ease of lifting it in and out. I get good even heat throughout. I did ribs yesterday and managed to catch them right at the "weep" it was perfect.
 
I've done a lot of experimentation with my UDS, using up to five thermometers, and found the same thing: thermometers can show 20-30 degrees difference even though they are a few inches apart, and sometimes they can show the same temps. I haven't been able to find any rhyme or reason to why they change. I've just started to use a deflector and that seems to help.
 
I've done a lot of experimenting as well with multiple thermometers , without a diffuser , regardless of how I load my charcoal basket(which is 17" wide) it runs 50 degrees hotter in the center than at the side of the drum. I have a second grate 6 inches down , I have tried a clay saucer on that grate and I wind up with much higher temps around the edge of the saucer with a cold spot dead center. I attribute that to the saucer being too far from the fire , too close to the meat. I'm certain there is a sweet spot as far as diameter of the diffuser and distance from the fire that will make for really even temps in a UDS , I just don't know what those measurements are. When I first joined this forum , I read the entire UDS thread , there was a guy on that thread that was cutting out diffusers with different hole patterns and checking how the different patterns affected the temps. I followed it very closely but nothing ever came of it. I think if someone could come up with a solution to the uneven temps in the UDS , such as "you need a diffuser of X dimesions at X distance from the charcoal basket" it would be a major improvement , for an already awesome cooker.
 
One thing I've considered doing is adding some insulation to the outside of the drum. Has anybody tried that? The insulation would lower the amount of energy needed from the coals which could (I hope) reduce the flow of air and thus hot/cold spots. It might make the gaps between center/edge smaller since the outside of the smoker will be radiating less heat.
 
I also have the Big Poppa drum kit that I like a lot! As others mentioned a drum runs hotter in the center without a deflector. I made several style deflectors and think I have a fairly simple one that works. desert racer. I can make one for you to try if your interested.
 
Thanks for the offer but the one i used for my second cook was spot on both gauges. I want to post some pics of what i used but i work long night shifts and sleep during the day so i haven't had a chance yet, probably tomorrow.
 
I've done a lot of experimenting as well with multiple thermometers , without a diffuser , regardless of how I load my charcoal basket(which is 17" wide) it runs 50 degrees hotter in the center than at the side of the drum. I have a second grate 6 inches down , I have tried a clay saucer on that grate and I wind up with much higher temps around the edge of the saucer with a cold spot dead center. I attribute that to the saucer being too far from the fire , too close to the meat. I'm certain there is a sweet spot as far as diameter of the diffuser and distance from the fire that will make for really even temps in a UDS , I just don't know what those measurements are. When I first joined this forum , I read the entire UDS thread , there was a guy on that thread that was cutting out diffusers with different hole patterns and checking how the different patterns affected the temps. I followed it very closely but nothing ever came of it. I think if someone could come up with a solution to the uneven temps in the UDS , such as "you need a diffuser of X dimesions at X distance from the charcoal basket" it would be a major improvement , for an already awesome cooker.

I just laid an aluminum pizza pan (which came from the factory with lots of 1/8" holes in it)right on top of the fire basket, my fire basket is fairly tall at 12". Seemed to really even things out.
 
I promised some pics of what I used to even the temps out on my UDS. I used an aluminum broiler pan insert, wrapped it in foil, and placed it on a grate 12 inches from the top of the fire basket and 6 inches under my meat grate. Like I said the outer temp was dead on with the middle of the drum.
 

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For you guys who use a deflector, a question:

In my understanding, one of the beauties of an UDS is that the drippings form the meat fall into the coals and create steam. This adds some flavor back to the meat and helps keep the air from getting too dry. If this is true, do the deflectors keep the drippings from hitting the coals? Is this a problem? I've considered using tin foil with holes poked through it.
 
I just made his beauty out of 1/4 steel. Made my drum alot more even cooking. Just did a brisket @275 last night, it is awesome
I put a whole chimney starter of lump on top of 10 lbs of B&B oak with a mini split of pecan. The juices still drip though the holes, but this thing works well. I don't have temp guages on the side but I could feel the sides am felt alot hotter even though I was cooking at the same temp I always do.
5A16D483-408D-407A-942A-E60F25287274-1747-00000240F302FCBC.jpg
 
For you guys who use a deflector, a question:

In my understanding, one of the beauties of an UDS is that the drippings form the meat fall into the coals and create steam. This adds some flavor back to the meat and helps keep the air from getting too dry. If this is true, do the deflectors keep the drippings from hitting the coals? Is this a problem? I've considered using tin foil with holes poked through it.


If you want that "open pit flavor" you can use a diffuser with holes in it and the fat will still hit the coals. Some people are using diffusers as drip pans to catch the fat because they don't like that flavor. While others such as myself are using them solely to even out temperatures at the grate.
 
Yep, 50° hotter in the center is what both of my drums run. I have tried a couple of indirect set-ups and don't like the hassle, plus I like the flavor without them. (Fatties are an exception, if I do 8 or 10 I will use a drip pan.)

In a drum, it's necessary to not only turn the food..... but I spin the grate a couple of times during the cook as well.
 
For you guys who use a deflector, a question:

In my understanding, one of the beauties of an UDS is that the drippings form the meat fall into the coals and create steam. This adds some flavor back to the meat and helps keep the air from getting too dry. If this is true, do the deflectors keep the drippings from hitting the coals? Is this a problem? I've considered using tin foil with holes poked through it.


It's not creating steam but rather tasty cancer. There are two distinct carcinogens created when fats hit the coals, these carcinogens get into the air, the smoker and on your food.
 
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