THIS IS A SMOKER UPDATE. I’ve reached a milestone. I’ve learned to control my temperature.

Old Smoky has been in place in my backyard since November and working beautifully.

This week I want to share my evolution as an amateur pit master to aid others who may have plans to purchase their own 450-pound offset smoker big enough to feed a restaurant and place it in their backyards.

Some smokers come with push-button easy temperature and smoke controls. With a pellet smoker, you can set it and forget it. Bullet smokers are inexpensive and work beautifully without too many variables.

Offset smokers, however, where the firebox is separate on the side of the cooking chamber, take some finesse. Because mine is welded locally and huge — the cooking chamber is 42 inches wide, 2 feet diameter; the firebox is 2 by 2 feet — there is no instruction manual, no online group forum for model owners, and plenty of room for heat and smoke fluctuation.

I have to learn my own smoker on intimate terms. Old Smoky and I must become close friends.

He is big and volatile, one of a kind, challenging to manage, like Lennie. Many pork ribs have to be spared. Many chickens must give their best.

I’m still learning, but I had a milestone moment on Saturday.

For two months I’ve been having radical heat variations top to bottom, and it’s been making me crazy. My bottom is hotter than my top.

I have two built-in dial thermometers that are positioned level with the top food shelf inside the chamber, though I seldom cook on the top shelf. On the bottom shelf, where I do most all of my cooking, which is only 10 inches below the top shelf, I clip a digital thermometer with a wire leading out to a remote transmitter. I read the receiver from my shirt pocket.

When I’m in the middle of cooking, the bottom will say 300 degrees, while the top reads 240 degrees. Huh? A 60-degree difference with only a 10-inch height difference?

Once, I caught a photo of a shocking disparity. It was 100 degrees hotter on the bottom. What’s with that? It’s only 10 inches lower. I thought hot air rose? Why is the bottom hotter? I posted my question on barbecue websites with no replies. My conjectures continued. Was it because heat rises, but it must always pass through the bottom to get to the top, thus the bottom will always be hotter? How can I cook two shelves of similar meat?

Many experiments later, I was still consternated. I tried playing with a steel deflection plate across the bottom. I could slide it toward the firebox and shift the heat flow under it to the right. I put a pan of water on the bottom and a few fire bricks on each side to hold and hopefully balance the heat. It helped a little.

I made sure all my thermometers worked by clipping my digital at the same height as the two built-in dial thermometers. They all three read the same. To be sure, I Amazon Primed a new high-end dial thermometer — the Tel-Tru BQ 300 — to replace one of the generic, default thermometers. At the same elevation, I again got agreeing temperatures. All three worked fine.

I tried cooking spare ribs on the bottom shelf using only the built-in dial readings. They cooked too fast. They were done before they were tender. They were hotter than the elevated dials indicated.

I cooked a chicken on the bottom shelf using only the digital reading clipped right beside it, ignoring the dials telling me the temp was too low. The chicken wasn’t done on time. What the heck is going on?

On milestone Saturday I woke up at six o’clock. I promised to cook for a family Christmas lunch. I began cogitating over this heat problem, and got up at 7 a.m. to start a fire in the smoker. I wanted to play with it before I put on the meat.

I attached my digital remote thermometer to the lower shelf, started the fire with charcoal and two logs of cherry, and sat out there for two hours drinking coffee and watching. That’s when I saw with my own eyes the truth of the matter.

I thought it was the size of the chamber, or the size of the fire, causing the confusing fluctuations. I thought the bottom was always going to be hotter than the top.

That morning I realized it was the age of the fire making the difference. When the fire was young and growing, the top of the food chamber was hotter than the bottom. At middle age, the temperatures were balanced top to bottom. As the fire aged and glowed coals, the bottom became hotter than the top.

Until that morning I generally started my smoker fires and then walked away for a half hour, waiting for them to turn to smoldering coals. I wasn’t seeing that early rise. Now I see it’s all about timing my fire feedings. I need to either keep my fire burning at middle age, or compensate for its fiery youth and cooling seniority in my temperature readings.

Saturday’s ribs, chicken, and bacon-weave sausage rolls all came out perfect. There were my best so far. I’m satisfied at last. Smoky days are ahead.

Steve Gibbs teaches at Benicia High School and has written a column for The Herald since 1985.