Hey LizzieG. Glad it was a success! Beer always makes up for all but the worst Q mistakes.
Sounds like you did everything right as far as setting up your
WSM. Folks who live in the colder environs might have better input than my Northern CA brain. I think the coldest outside temp I've smoked is 38F. Did two smokes this weekend and it was a bone tanning 82F. Physics is physics though and keeping a
WSM or any smoker at temp is a matter of physics. My apologies for the long answer below but my engineering educated grey matter seems incapable of short answers.
When the temp is that cold you've got three issues, especially when you've got water in your water pan. First, the available heat from the burning fuel has to warm the cold air entering the unit. Second, the cold outside air is sucking heat through the uninsulated walls of the
WSM. One of the reasons why folks wrap their WSMs in cheap welder's blankets is to insulate the
WSM from the cold ambient air, allowing the available burning fuel heat energy to do what it is supposed to do, keep the air inside the unit at the desired temp. Third, the available heat has to heat the water, even if you started with hot water.
Assuming you don't buy a cheap welder's blanket you'd probably be better off with a dry smoke, ie, no water in the water pan, when it is that cold. I dry smoke 95% of the time in my WSM only because it is more fuel efficient and I know how to control my temps well enough. I don't need a heat sink to stabilize temps, which is the water's major task, but it does work well when I use water.
Second, the minion method. I've done it. Some swear by it. I don't use it but others might pipe in who live in the cold. Personally, if it was that cold I'd lay down a layer of cold briquettes and wood then dump a full chimney of hot briquettes over the top of the cold ones, spreading them out just a little but leaving a nice center pile for concentrated heat. If the cold briquettes loaded in the WSM were kept outside in 28F temps, they'll suck a lot of heat out of the hot briquettes to get to their ignition point but with a full chimney you should be fine.
Third, once you get the unit up to temperature, try closing down the upper vent to 1/2 open to keep the heat in the unit and to see what it does. I use all four vents to control my temps and have yet to run with them full open, even with 350F smokes. Remember, when it is 28F outside, pulling cold air through the WSM requires more heat energy to warm it up to your desired temp. If you restrict the volume of cold air entering the unit but still allow enough air flow for a steady burn, you'll be able to keep your temps up easier. Closing down the top vent controls the air flow into and through the unit from the lower vents. You'll find you can probably close down the lower ones too. That's part of the art of temp control and minimizing fuel usage.
Finally, adding hot coals and the "chute" you already have attached to your WSM. When I need to add hot coals during a smoke I get the chimney roaring hot with a half load or less of briquettes. Wearing protective gloves I open the side door on the WSM, kind of lift it a little and wiggle it around so I can tilt the door about 45 degrees, then carefully but quickly dump the hot briquettes onto the tilted door. The door acts as a chute and the hot briquettes roll right into the hot coal pile. Then I use my long tongs to reach into the unit and kind of spread them around equally. Practice with a cold WSM and cold briquettes before you try it first with hot ones. It's really easy.
I'll bet you'll have your WSM technique NAILED in another smoke or two. Then we'll be asking you for advice!
