that comes out too dry, even with a brine.

Need to do some more reading.

My normal method of cooking chicken is to spatchcock, salt both sides liberally, wrap in cling wrap, and store in the refrigerator for 24-48 hours. I do this in lieu of brining.

I oil up the skin, cook in my smoker at 250F for about 2 hours until the breast reaches 140F, then finish in my broiler until the skin browns nicely (about 10 minutes). By the time I take it out, the lowest breast temp is about 148F. Per the USDA chart, only a 4.4 minute rest is required, but I give usually give it at least 10.

I did this for the first time last thanksgiving, and it came out wonderful.
(I also brined it, and marinated it.)

I find that brining keeps it moist enough, especially with roasting. I treat poultry differently on how I cook it, but not matter how you cook it, it gives off lots of water.

I try to cook it just enough without drying it out. I think there is no rare or medium rare with chicken.

Brining helps with keeping meat moist due to salt infusion, however while the brining liquid brings salt into the meat, it also removes some of the meat flavor into the liquid which is then discarded. That's why I don't brine anymore and instead use a different method. Salting the meat and allowing time for the salt to draw moisture out, which then returns back into the meat along with the salt. With chicken I go with about 24-48 hours which allows enough time for the salt to penetrate without overly curing the meat.

The foodborne pathogen danger with poultry is salmonella, so it needs to be cooked sufficiently to insure those pathogen levels are reduced enough for the meat to be safe. This is exactly what pasteurization is. Pasteurization requires either a high temperature over a short period of time, or a lower temperature over a longer period of time. So long as you are at a sufficient temperature above which the target pathogen can't survive, pasteurization can be achieved at any temperature.

Proteins denature differently at different temperatures. Consider a soft boiled egg vs a hard boiled egg. With a soft boiled egg, the whites of the egg are just starting to firm up and the yokes are still in a liquid form. A hard boiled egg has firm rubbery whites and a dry and fully solid yolk. This is because the protein strains become very tight and squeeze out moisture. Since the whites and yolks contain different proteins, they coagulate at different temperatures, but it's possible to cook an egg for hours at a lower temperature and maintain a liquid yolk and a soft white.

A similar thing happens with meat proteins. Higher temperatures cause them to become less moist as the moisture is squeezed out of the protein. Cooking at lower temperatures allows the meat to remain firm, yet still more moist, and so long as sufficient time and temperature are maintained, the meat will be as safe as if you had cooked it at higher temperatures.

Using sous vide methods, I've cooked chicken at 140F which was perfectly safe to eat. The problem is the meat is still a bit mushy and the color is pink, which tends to freak people out. If you go with a little higher temp, the meat firms up more and the pink color disappears.

A similar thing happens with meat proteins. Higher temperatures cause them to become less moist as the moisture is squeezed out of the protein. Cooking at lower temperatures allows the meat to remain firm, yet still more moist, and so long as sufficient time and temperature are maintained, the meat will be as safe as if you had cooked it at higher temperatures.

I thought that you brine something like a turkey, because it needs a lower temp over a longer time to get the whole bird evenly cooked. And the longer time means more time for moisture to move from the middle to the outside and evaporate. Brining is a counter to this by bringing more H2O inside the bird, so that, though, it leaves more salt, you end up with a juicier turkey.

And with higher temps, like 425 F, you can cooks poultry parts without brining, because it does not leave enough time for much water movement.

I'm not saying you are wrong, because cooking is a consistent learning thing for me. For example I now think that marinating is a form of brining. I made the mistake of brining chicken first before marinating for stir fry. There was less flavor post brine...I figure because the marinade had no place to go. It should have been obvious, but sometimes I don't think things out.

Remember that meat is already mostly water. Consider a piece of well aged beef at a top steak restaurant. The objective of aging is actually to remove some of the H20 from the meat. Since H20 is actually a very effective thermodynamic heat sink, removing some of it concentrates the meat flavors and allows it to cook faster and at higher temperatures. The end result is a juicier piece of meat that has more flavor even though you might intuitively think it would be dryer.

There's actually two distinctly different ways to brine. There's the wet method and the dry method. Literally speaking, brine is a solution of water and salt. So when brine is mentioned in relation to preparing meat for cooking, most people think of soaking a piece of meat in around a 7-10% salt to water solution. Meat is already mostly water, so rather than injecting more water into the meat, the real objective is to infuse the meat with salt which will allow more of the moisture to be retained during the cooking process. So a wet brine certainly accomplishes that goal, but as I mentioned the disadvantage is that you're also dissolving much of the inherent flavor of the meat out into the brine solution never to fully return.

A dry brine is literally an oxymoron, but figuratively it just describes a different method of achieving the same objective. If you sprinkle any piece of fresh meat with salt and wait at least 15 minutes or so, you'll notice that some of the moisture is drawn out of the meat and is now on the surface. This moisture dissolves the surface salt and through the process of osmosis draws it back into the meat along with the salt itself. So what you are doing with a dry brine is creating the salt solution with the meat's own juices. After 24-48 hours, a small amount of water will evaporate, but what you are left with is a salt infused piece of meat that has a more concentrated meat flavor which will retain more of the moisture during cooking.

There's all sorts of thermodynamic tricks you can use to minimize evaporation and varying the cooking temperature is one of those, but the basic problem with poultry remains. Unless you want to take a chance on making your family sick, you have to one way or another pasteurize the meat entirely from the outside in. The nature of protein is that higher temperatures denature those proteins in such a way that moisture will be forced out even more effectively than evaporation. So within certain limits, a piece of poultry cooked to a lower internal temperature will be more moist than one cooked to a higher temperature. That's one of the reasons why sous vide is becoming increasingly popular as a method for cooking protein.

I'm still learning more about cooking every day. Some of this comes from reading about it, and some comes from my own experimentation, but through practice I try to pass on what works and what doesn't and I think that even methods that have served you well for a long time can still be improved through food science.

With turkeys I always have that pop-up thermometer which has always proven reliable to me.

With everything else, I've just acquired enough experience to tell when things are done.

The problem is that most are set to around 180-185F which is well above the FDA recommended internal cooking temperature of 165F, and if you let the bird rest for even as little as 10 minutes the temperature will climb another 10F at least through carry over cooking. As long as you are fine with the taste and texture which results, there's nothing wrong with it and cooking to that high of a temperature definitely takes the guesswork out of any food safety concerns.

Experience can also let you know when something is done. If you are cooking the same thing, with the same dimensions, using the same methods, it's pretty easy to achieve the same results consistently and even if you vary one of those parameters, experience can also allow you to make an educated guess as to what the end result is going to be.

In my case I am constantly trying new things, and meat is just so expensive and generally unsustainable that I usually don't want to rely on guesswork, not to mention that I prefer to operate closer to minimum safe time and temperature levels. I have a number of different temperature measuring devices and I use most of them quite often.

This past Christmas I fixed a turkey, and for some reason there was no pop-up thermometer, which I've grown to rely on. It came out dry. Yuck. Every time I use the pop-up, they turn out perfectly.

More to the point, I think that experience is often overlooked. We forget that our grandmothers and even earlier generations didn't rely on precise measures, but grew up learning to cook at the feet of others who'd been cooking without measuring. Don't get me wrong. I appreciate that my oven has a reliable temperature, and I'm very happy to have various measuring devices. But I also happen to live and cook at 7,000 feet, and anyone who sees this who's at all befuddled about high altitude cooking, let me know.

I will say this about high altitude: In the late 80's I lived in Boulder, CO, at about 6,000 feet. I adapted all my recipes to that altitude. Then we moved to the Kansas City area, where regular sea-level recipes were just fine. Now I live in Santa Fe, NM, at 7,000 feet, and there is a difference between what works here and what worked in Boulder. It's not huge, but it's there.

http://www.thermoworks.com/Thermapen-Mk4

I have a few of their products although the Thermapen isn't one of them.