Pointers for UDS temp control?

[caliking]

Howdy brothers.

UDS is ready! I promise I'll get some pics up before the weekend.

Seasoned it last night with veg oil. Placed 1 chimney full (from Lowe's... smaller than the Weber chimney) of Kingsfiord regular briquettes with 10 lit (unlit arranged around the lit... didn't have coffee can handy). The lit briqs were not completely ashed over yet when i added them to the unlit briqs). Had one intake (3/4") and the ball valve (3/4") open all the way. Using a dome lide from a cheapie kettle grill and the vents on the dome were fully open. had one probe from my Maverick ET-7 on the grate. Grate is 23.5" above the bottom grate of the charcoal basket

Saw some white smoke for a little while then things seemed to settle down. The temp rose steadily to 225, 250, 270's. That's when all hell broke loose. Tried to close the ball valve halfway... still rising to 280 (but slower). Closed the intake completely with ball valve open a titch. Rose to 290's. Closed the vents on the lid - rose to 300's. Opened the vents on the lid and the temp dropped a little. Took the lid off to let the temp drop to the 260's, but then temp rose to 300's again with the lid on. waited about 30mins between each change. After 3 hours I stopped the experiment - closed all vents, intakes, valve and went to bed (1am).

I don't think my build is drafty, because after I closed everything up, little charcoal had burned up when I checked it this morning - probably have half a chimney or more left. I know I ended up making more changes than I should have during the burn, but part of it was for me to figure out how the temp would be affected.

Any pointers? I have read that many UDS builds will cruise with one intake open and the ball valve open 1/4 to 1/2 way.

Thanks for reading! :-D

[likeadeere]

Well, I've got about 5 cooks on my 'new' UDS. I was doing fine keeping everything under 250 until my last cook. My last cook was a butt, it turned out excellent. But when I started the cook, I think I panicked. I filled my 12" fire box to the brim with lump, because I thought I would need more lump for the 14 hours the butt was going to need. I could NOT keep the temp under 325. I was panicking also because it was getting late. I figured the butt had to go on by 10pm or I wasn't going to make lunch at noon the next day. My logic was that the longer the smoke the more charcoal I would need. So I filled it up. I ended up dumping out 2/3 of the lump out of the basket, and just going with it. I took a leap of faith: 1/3 lump in the fire basket, one 3/4" intake open, exhaust open all the way - and went to bed. I awoke at 7 am (slept in!), looked outside and the temp was steady at 225!! Conclusion: I panicked and filled up the firebox WAY too much. The amount of lump I've used for all my cooks will last for a looooong time. Did I mention the butt was phenomenal??!! hope that helps joe

[sdb25]

Every drum runs a little different, but they all tend to be somewhat similar if you are following the standard design in the UDS thread. This is what works for me, after lots of trial and error...

I load my charcoal basket about 2:1 briquets to chunk hickory (by volume). Then I start 15-20 briquets in the chimney and add them when they are ashed over 100%. I dump this on top of the unlit basket, and arrange them about evenly (don't worry too much about where you put the lit coals; the fire is gonna burn where it wants). I don't mess with the coffee can method; sounds good in theory, but is really just science fiction in my opinion.

So, next step depends on what you are cooking. For chicken, I leave the lid off until I see little flames coming up from between the coals since I usually run the drum at 300 degrees. Then I put on the meat, lid on, and all 3 intakes wide open, as well as the lid vent (I only close the lid vent when I put out the fire, otherwise it's always wide open).

For brisket, pulled pork, and ribs; I run my drum at 225-235. I put the lid on as soon as the lit briquets are in the basket. I leave all intakes wide open until the drum hits 200 degrees. At that point I put on the meat, and cap one of the intakes. When the drum hits 220 degrees, I cap the second intake. At 225 I close the last intake 50%, and fine tune things throughout the cook as needed.

This is what works for me. Give it a try.

As for cooling your drum by opening the lid, that lets heat out but also lets oxygen in. The temps will drop then shoot higher than when you opened the lid. To cool the drum reduce airflow to the fire/to heat the drum let more air in. Make slow changes and see what the drum is doing after 10 minutes or so.

Good luck!

[indianagriller]

Temp in the uds depends on how much hot charcoal you start with when i do low and slow i use about 1/4 of a chimney you may try a smaller amount of fuel next time, also it looks like you had too much air in the beginning and were trying to play catch up, try starting out with only one intake half open then go from there.

[IronStomach]

(1) Don't close the lid vents: that will keep hot air in (raising temps) and let stale smoke play naughty games with your food.

(2) Don't feel bad about closing off all the intakes though if need be. And choke proactively, if you want 250 and you're at rising towards 240, start choking it down a little.

(3) All that, get a couple cooks on it then worry about temp control: it'll handle temps much differently once you get it well seasoned.

Have fun!

[caliking]

Thanks for the tips! Will definitely get more practice in.

@IronStomach: when you say get a few cooks done to get the UDS well-seasoned... does it need to be oiled again each time?

[IronStomach]

Thanks for the tips! Will definitely get more practice in.

@IronStomach: when you say get a few cooks done to get the UDS well-seasoned... does it need to be oiled again each time?

No it doesn't. First time is enough and whenever you clean it (try not to clean it unless you have a very good reason).

The food you cook will supply the seasoning grease after the first run. Try fatties, pork butts, beer can chickens, aramdillo eggs. Basically part of the issue is fluctuations in temps from the sidewalls transferring heat. Once they're coated in cooked meat grease from a couple of cooks, that evens out a bit: plus you learn how to control it better.

Basically, get a system down for supplying fuel and lighting it and then for reacting to temperature variations: do it the same way every time to minimize variables. That way when you want to change something, you know what's normal and what you're changing. That's what people call experience. 8-)

[caliking]

Where can I find this "experience" you speak of? Is it in the pork section? coz if its next to the broccoli, I'll never find it! :twisted:

Just being a smarta*s. Didn't think about seasoning working in that way. Thanks for the advice.

[IronStomach]

Where can I find this "experience" you speak of? Is it in the pork section? coz if its next to the broccoli, I'll never find it! :twisted:

Just being a smarta*s. Didn't think about seasoning working in that way. Thanks for the advice.


Hehe, no wonder broccoli smells funny, it's experiened. :-)

Fun fact of the day: kung fu literally translates as "hard work, over time," which is basically what experience is.

[MushCreek]

As was said, every drum is a little different. It sounds like you started with too much lit coal, and then didn't throttle it down in time. You also have to be patient- those big drums react slowly to changes. Mine seems to settle in nicely at 225 with one 3/4" vent open. Also as was said before (but bears repeating) DON'T close the exhaust when you have food in there. It causes creosote formation on your food. It tastes like crap, but at least it won't rot!

[Captain Dave]

I agree with mush creek, mine cruses at 225 with the ball valve open about 3/4 and the nipple caps on. Maybe 7/8 in cold weather. Doesn't matter how much I fill the fuel basket. It helps to catch the desired temp on the way up. Opening the lid will always cause a temp spike by letting more air in.

[Rookie'48]

I use a weed burner to fire up my UDS. I only let it run for about 30 seconds, then put on the Weber lid (exhaust wide open when cooking) and adjust my intakedown to a 1/4" gap. I have a single 2" intake running up the side of my drum. It's much easier to catch the temps on the way up and my drum takes about 20 to 30 minutes to react to any adjustment on the intake. I hope this helps, but YMMV ;>)

[MadKirk]

Keeping the lid closed helps a lot too, from what I've found so far. If I open the lid for any reason, I spend 30 minutes trying to get the thing back under control. I haven't figured that part out yet.

[MushCreek]

If you need to open the lid for something, throttle your pit down for a while beforehand.

[jeffjenkins1]

I don't sweat the temp spikes from opening the lid. If it was holding at 250 for 2 hours before the lid opened, it will spike then go back down in 20 minutes or so. I never "ruined" some que with a spike. I set it and forget it, literally. Some times I have to set my alarm to be sure I check it.

Jeff

[MadKirk]

I don't sweat the temp spikes from opening the lid. If it was holding at 250 for 2 hours before the lid opened, it will spike then go back down in 20 minutes or so.Thanks for the tip. That may be my problem. I try to control the spike, even if it has been running fine the way it's set.

[Kcinnick]

I learned to get my temp to 235*ish I start with 10 lit coals. The biggest help keeping temp under control was getting a good seal on my lid. I hammer the rim out flat on a weber kettle lid, I then put it on my uds and hammered the lip to fit perfect on my drum.

[caliking]

Thanks for all the great tips.

I ran experiment 2 last night. Had about a half chimney of unlit charcoal and 7 lit briqs (I thought I had 5, but 2 more sneaked in somehow).

Closed all the intakes except the 3/4" ball valve which was fully open. Came up to about 230ish in 30mins, then I closed the ball valve halfway and it slowly crept up to about 250ish and stayed for an hour or so. I then closed the ball valve to about 1/3rd open to see if I could make the temp fall. Went to 260-270 for some time then started falling. Decided to end the experiment and call it a night (2am... wife wonders what the hell I'm doing)

This run was more controlled and gradual as opposed to the wild ride and craziness of the night before :eusa_clap. My conclusions thus far:

1. don't open the damn lid
2. try to be proactive instead of reactive in terms of throttling down
3. use only a few lit briqs.
4. don't show your wife how a propane torch works. She'll smell gas in the next county and think your propane tank is leaking and will burn the house down... sheesh.
5. its hard to drink a beer with a face shield on (and down).

Will see if I can tweak some more in prep for my first cook this weekend!

[IronStomach]

Sounds good... what in blazes did you need a face shield for?

[griffew]

Good tip.

[caliking]

See #4 above re: the faceshield... wife made me wear it because of the blazes... next time I'll wait for her to go to bed... but then many of the brethren have probably figured that out already :-D

[MushCreek]

Good thing she wasn't around when I burned my drum out with a pile of very dry pallets!

Sounds like you've got a good handle on it now. Gotta love the Brethren!

[Red57Bird]

I use the fridge magnets to control air flow in my UDS and have had very good luck keeping control of the temps. I keep all three vents open at about 15% and it works well for me. Even when I open the lid, the temp drops a bit for a minute or two, and them pops right back to where it was previously. I figured having all three bottom vents open to some degree would provide the best possible burn and temp control. So far so good.

My last cook I struggled with keeping the temps down a bit, but after reading this thread it looks like the mistake I made was starting off with too many lit coals. I'll be cooking on it Saturday in the snow storm so that should be interesting. I'll try and post some pics on Sunday.

[IronStomach]

See #4 above re: the faceshield... wife made me wear it because of the blazes... next time I'll wait for her to go to bed... but then many of the brethren have probably figured that out already :-D

Heh, my wife was out in the snow with me while the flames were shooting out of the drum... beer in hand toasting the prospects of future que. :-D

[pinghacker]

2 things:

1) Close all intakes 5 min before lifting the lid and keep them closed for 5 min after.

2) In windy conditions, you need to close off some of the top vents. I have 6 1/2" holes in my lid and if the wind is kicking up I close 3 with magnets. Otherwise the wind will suck more air through the system and you won't be able to keep temps down.

[caliking]

Ok... so I ran experiment 3 tonight (last night?) in prep for my first UDS cook tomorrow (today?). I think I have a fair handle on how to regulate the temp and kep it between 225-250 without making too many adjustments - still learning though, so I need to adjust about once every hour.

I noted that my build is not as tight as I initially thought - I saw some white smoke leaking out from the rim of the lid when after I added 5 lit briqs to a chimney of unlit briqs. Should I look for a high temp gasket of some kind (if so what do I need and how do I put it in place?) Or should I take a mallet/heavy hammer and try to get a better seal on the drum? :confused:

I plan to smoke 2 racks of babybacks and a beer can chicken. I estimate this will take 4-5 hours. Should I load everything up at the start or should I put the chicken on after 1 hr so that the ribs get about 5 hours and the chicken takes about 4?

Oh, and as promised, here are pics. I tried to keep it simple but got carried away with the charcoal basket and ash pan. The pics don't show the Traeger thermometer I put in the lid, which by the way did not work out as planned. I thought maybe the lid thermo would be off by some amount and I could just remember what he difference would be. Instead, the thermo lags by 50* when a grate probe reads 150*, then an additonal 10* for every ~100*... so off by 50*, then 60*, then 70*. I can't remember any of the calculus I learned (and forgot) so long ago, so I think I will move the Traeger thermo to grate level later.

Last thing - I noticed that after 3 test burns, there was some discoloration of the grate and the stem of the thermo stem. I lifted the lid and there was a scant amount of dark fluid on the lip of the lid... felt somewhat oily. Is this the dreaded creosote ad will it get on my food??:eusa_clap Or did I just season with veg oil too generously when I did the first test burn?

Pic 1: My first UDS... getting uglier by he minute:-D
Pic 2: View of the intake mod (nothing special, but I'm still proud of it)
Pic 3: inside view... I made the grab bars to leave space for a coffee can to be pulled out easily. Now I realize that I will probably not use a coffee can.
Pic 4: Ash pan. I like that it is not attached to the basket. The middle post is a handle to lift it in and out of the UDS.
Pic 5: Groceries!! I laid out a bunch of sauces since I haven't made up my mind yet which one(s) I will use.

Have a great weekend brothers! May the smoke be with you...:biggrin:

PS: just realized that some pics are sideways... sorry.

[ChrisChaos]

Wow that really looks good..Can't wait to start on mine. Love the Beer opener lol

[Skidder]

I too found my second UDS (Weber lid)temps were out of control the first couple of smokes but then after a few cooks it seems to have settled in. My first UDS (flat lid) never missed a beat from day one. Now I like them both only difference is the Weber lid one holds more but both run between 225-265 all day (night) long.