Dome Temps/Cooking level temps

Nature Boy

Enjoying a friday evening, cooking a monster brisket for lunch tomorrow. A few things I figgered were worth mentioning. A lot gets talked about "dome" temps here, and they can be a fair guide to helping with your cooks. For some reason I have not yet bothered monitoring my cooking level temps, but since I have been noticing a huge difference in cooks lately...depending on my indirect setup, i decided to throw a couple polder probes in on the cooking level.[p]I have a full load of lump (with some wonderful Pecan..thanks JJ..and some apple wood). A platesetter is upside down on the fire ring, and an oven broiler pan is my drip pan. I elevated a grate (and brisket) about 6 inches over a drip pan (with coke and water in it). After about 2 hours, I had the dome temp about 240. My cooking level temp was 180. That is a 60 difference. Now, after 4 hours, the cooking level is 190, and dome temp 230...so it is starting to level out. But still a considerable difference.[p]I put liquid in the pan for a change, and planned on going with 225 instead of my normal 250 dome....since I kinda want to draw the cook out a bit longer anyways. But I thought is was most interesting to see the big difference in cooking level/dome temps with this setup. Would be cool if some of the other folks here could map the temp differences with their particular setup...and post the results.[p]And if 230-240 dome equals 190 cooking level, everything points to going with 250 dome. Of course without water in the pan, the difference between cooking level and dome is probably much less. Gonna start monitoring cooking level temps from now on. Still lots to learn.[p]Beers and briskets to yall.
NB

Marv

Nature Boy,
Learning is such great fun isn't it?
I learned this when I first started when I had a New Braunsfeld BD. The temp gauge was near the top and I was cooking at the recomended 200-225, or so I thought. I almost always had to bring it in and finish it in the oven. I was getting discouraged quickly, when it hit me in the middle of the night. I woke up from a dead sleep and my wife thought there was a burglar in the house.
I figured that if heat rises and if the meat was 6-8 inches lower than the temp gauge, the meat was cooking at a much lower temp than the recomended 200-225. That is when I got my Polander and now own several.
I had to raise my temp gauge to 325 to cook at 200 on the meat level. No problem after that.
When I had my comerical units built, I had the gauges mounted at the grate level and have had no problem.[p] Moral of the story: raise the dome gauge temp so that the grate temp (actual cooking temp) is right for your cook.[p]Marv
www.marvsbbq.com

Cat

Nature Boy,[p]I spent a lot of time pondering & measuring all this with my engineer buddy. Since then I always monitor grill temp, because in my experience the relationship between grill & dome varies a lot - depending on setup (direct or in-, water pan or not, elevated grill or not), weather, cooking time, dome temp, etc. [p]With so many parameters, it's hard to predict what the spread will be. Posting a probe at grill level tells me what the chunk o' protein is experiencing...and I don't have to do any tough math. [p]Over a many-hour cook, dome & grill temp tend to equalize. But this may take several hours, especially in cold weather. When I do a butterflied chicken, direct, at 270 grill, the dome temp is anywhere between 280 and 330. [p]Another big benefit of cooking by grill temp: it's easier to exchange recipes/techniques with people who use a different type of cooker.[p]I've gotten lazy about keeping notes. Thanks for the nudge, Chris ole buddy. [p]Cathy

Nature Boy

Stogie,
Great idea about slipping the probe through an end of the meat. Yeah...I am suprised I have not tried this before. I have had great luck cooking my briskets at 250 dome for the past 3 years. Looks like I was cooking them in the 200-210 range in actuality...which explains the longer times than I hear from those that use other cookers.[p]I had heard differences reported of 30 degrees or so between dome/cooking level. During this cook, with liquid in the pan, there has been a consistent difference of 50 degrees or more the entire cook. Just opened up the vents a bit this morning, as the plateau is wrapping up, and the dome is nearly 300. Cooking level 230.[p]It'll be interesting to get some more feedback if others start monitoring the cooking level. My next test is without water in the pan...like I normally cook.[p]Today, it's brisket and beer time!
Thanks for the tips.
NB

Nature Boy

Cat,
Your past posts about this were first in my mind when I decided to start dong this. So, you experience a difference of anywhere from 10 to 60 degrees, and that is direct! [p]The dome temps that get used here all the time are great for reference, but with all of the different setups folks use, maybe that explains some of the difficulties people have from time to time after following a recipe with dome temps as a guide. Certain setups have only a minor difference between dome/cooking level....while other setups have a 60 or 70 degree variation. Pretty substantial.[p]Thank YOU for opening my eyes up to this in the past!
Great weekend to you and Roy. The weather here is better than fine. Great day for brisket.
NB