How Far Out Of Whack Can Your Thermometer Get?

Citizen Q

So when I was setting up the Egg to do a couple of slabs of spareribs Sunday, I noticed that the dome thermometer was pointing straight down instead of reflecting the ambient outdoor temperature of 49 degrees, so while the fire was catching, I removed the thermometer to calibrate. Now before we get into a discussion on barometric pressure, just let me tell ya that as far as I'm concerned, water boils at 210 degrees because 210 is the first hash mark above 200 so that's my calibration mark. It took quite a bit of adjustment as the thermo was only reading 100 degrees in a pot of rapidly boiling water, but I set it straight and replaced it in the dome. I got the fire well established, placed my setup of firebricks to warm up for 10 minutes or so at 350, then yanked everything to bring the fire down and the smoke up with a couple of handfuls of good & wet hickory, apple and pear wood chips, replaced the setup and on goes the meat.

Now I was experimenting with a new (to me) method of smoking the ribs straight thru, indirect, no foil or sauce, at 210 degrees dome, and simply spraying every hour with a mixture of apple juice and cider vinegar. I also filled all the remaining space around the perimeter of the main grid with a dozen Johnsonville Brats. I was a bit surprised come the four hour mark that the ribs were showing no signs of shrinkage and the brats were still very squishy to the poke test, so I cracked her open a bit and brought the dome temp up to 230 to finish things up a bit quicker. At six hours, I stuck the ribs in a good meaty spot with a digital Polder thermometer fork thingy piece-o-crap Christmas gift and watched as it slowly climbed one degree at a time from 45 to 132 over the course of about a minute before it somehow magically reset to 45 degrees and started climbing one degree at a time again, then just started flipping back and forth between 45 and 68 and I realized that I din't have time for this crap, the season premier of Deadwood was about to start, and nothing looked even close to done yet anyway, so I shut the lid and let it go for another hour. At hour seven, 10:00PM, the meat on the ribs was just beginning to pull back from the tips of the bones, but the brats seemed nice and firm and well browned so I took them out, sprayed down the ribs again and went back inside to watch Carnivale (dontcha just love HBO on a Sunday night?)[p]After eight full hours on the Egg, I finally pulled the ribs out and wrapped em in foil on the counter til they cooled off enough to slice and put away. One slab was a good 30% larger than the other, the smaller one was burnt on the underside, but there wasn't much meat there to begin with and the meat on top was fine, not overdone at all. The larger slab never pulled back more than 1/4" from the tips of the bones and had no burning whatsoever, but the smaller end was a little bit dry and overdone while the larger end was still pink at the bone and very chewy, more like the consistency of a medium rare steak. The brats were good, but tasted and chewed like kielbasa, not what I was expecting. Everything was tasty and enjoyable, much better than any ribs I've ever had at any restaruant around here, but I think I'll be sticking to my own version of the 3-1-1 method from now on for ribs and grilling the brats quick over hot coals in the future. [p]Now, just to make a long story even longer, back to the original subject of my post. More snow was in the forecast for today, so this morning I went out back to make sure everything was in it's place and noticed that the temp on my Egg was reading 160 degrees. The rain cap was on since Sunday night and the lower vent was closed tight, so I opened er up to check things out and everything was stone cold inside. So now I'm wondering, just what the Hell temperature WAS I cooking at all day Sunday anyway? Looks like it's finally time for a new dome thermometer. Hate to say goodbye to old one though, she was so young, just 7 years old, that's only 49 in dog years. (Sniff).[p]Cheers,
C~Q

tach18k

Citizen Q, well first off a dome of 210 was way too low, should be at least 250, this would give you a grid temp of about 220-225. So rithly so your low temp was the problem for the very long cook. My thermo sits around 100 when not in use, but is accurate at 210 for boiling water.

Clay Q

Citizen Q,
Yea, time for a new thermometer. I think you were cooking at 210 when the thermometer read 210- and this made for a long cook. Then your thermometer got stuck on the way down when you closed things up.[p]At 210 your cold smoking and it's unsafe, I believe.

Citizen Q

tach18k,
I tend to think that, when there is a buffer of very large pieces of cold meat between the fire and the pointy end of the dome thermometer very close to that cold meat, a reading of 250 means that the grid temp is going to be much higher than that, not lower. When I'm smoking, whether it's pork shoulder, brisket or ribs, the meat is elevated into the dome anyway, so grid temp is not of much concern to me. I don't mind taking a little longer on the cook if it means a more moist finished product so 200-210 is the temp that I've been smoking at for years and the temp that I'll continue to use. It's my belief that since water boils at 212, give or take, meat that cooks in an atmosphere > 212 will release more of it's inherent moisture as steam than meat that cooks < 212.[p]However, the point of my post is that my thermometer, while holding consistent throughout the cook, was DEFINITELY NOT accurate. The accuracy of a tool, any tool, is paramount to it's effectivness as a tool. An attempted recalibration early this AM read the 14 degree outdoor temp as 140 and water boiling at 170. To use technical terms, my thermometer has "sh!t the bed". It is "NFG", a "former thermometer". (Insert you own Monty Python "Dead Parrot" euphymism here). Recalibration is not an option and it's effectivness as a tool in Sunday nights cook is certainly doubtful.[p]I did get 7 years of accurate usage from this particular piece of equipment without ever having to recalibrate and have no complaints whatsoever. I'm merely sharing my observations from a single particularly troublesome cook with others here so that they may use the information for their own benefit should the need arise. [p]Cheers,
C~Q

Citizen Q

Clay Q,[p]The thermometer has just gone haywire. I tried to recalibrate this morning, it was reading 140 when I pulled it out of the Egg in an outside temperature of 14 degrees and only rose to 170 in boiling water. I think I was probably only smoking at 170 -180 throughout the first part of the cook, and probably never even reached 200 when I kicked it up, which IS low but completely safe.[p]True cold smoking is done below 85 degrees and no cooking or drying of the meat is involved, think nova lox (salmon) or bacon. Hot smoking is actually done between 120 and 180, takes days or weeks to complete and the process involves curing with smoke and more drying of the meat than actual cooking. Think of those big red or yellow cellophane wrapped smoked shoulders or picnic hams at the supermarket, a completely different animal than what we cook. What we are doing in the Egg is barbeque, slow cooking, but still cooking, with lots of smoke for flavor and moisture retention with the added benefit of protection from harmful bacteria.[p]I prefer to do my barbeque closer to 200, I've been doing it that way for a long time and it works well for me. I'm far from alone in my thinking, but then again there is no shortage of those who cook at 250 plus either, and thats what works for them. It's only barbeque after all, there are no "rules of engagement". There are easily over a million different ways to barbeque; 200 degrees or 300 or anything in between, foil or no foil, sauce or no sauce, tomato based sauce or mustard based sauce, vinegar in the sauce or no vinegar, sugar in the rub or no sugar or no rub at all. Hell, there's even been a shooting war over whether eastern north east central North Carolina BBQ was better than western north east central North Carolina BBQ. Can you imagine something so silly, any fool knows that the only real BBQ is eastern north east central North Carolina BBQ.[p]Cheers,
C~Q