I am very interested in this one because I am smoking a huge turkey breast tomorrow along with some country ribs. I always make the mistake of asking for info right before I need it, usually on a holiday when evrey one else is busy smoking meats!
The following is an OPINION. I am not making a claim to be any more of a chef or cook than anyone else and I am NOT a professional chef...but I did stay in a Holiday Inn Express once...
I am making my turkey breast simply for lunch-meat initially, but now I'm thinking maybe I should slice some thicker for dinners too.
Here's an idea, and you will not see this on a site like this very often...Microwave! Yep, a very useful device for re-heating foods that I hardly ever use as a primary cooking source, but as a re-heating tool it is unmatched for time and simplicity. You can heat a plate of something very quickly and if you do it right, it's a great way to re-heat food. We have one of those vented collapsible plate covers that works wonders on a dinner plate. BUT...you have to know what you are doing, know your microwave and know how to not overheat stuff. You can even revive leftover takeout Chinese food rice really well if you learn about it and practice it.
The puritans in here just spit up a little in their mouths and found a new dislike for me...I'm sure.
My feedback touches on the suggestions above too.
Jimmy has the traditional method. Tried and true. It's the basis of old school frozen entrees; only not frozen in this case. Using broth to keep the slices moist if you don't want to pre-gravy the meat.This is a chef's trick from way back and my guess is Jimmy has a lot of experience feeding crowds and may even do some catering. Cover with foil or a lid in a pan and "slow and low" like Jimmy says. That's why he said 300-325. You could do it faster but it will make the breast tougher the faster you bake it. You want to ease the temp up gently.
Same thing in the microwave. Slow and low and no foil! Cover with plastic wrap, slightly vented, or if the pan you are using is microwaveable with a microwaveable cover, use that. A microwave will heat the edges more, so if you do this on a large portion, stop halfway and move all the meat from the edges of the pan to the middle and vice-versa and spoon or use a baster bulb to re-distribute the broth too. Allow the microwaved pan of meat to rest responsibly like you would a roast, covered, for a good ten minutes, in the microwave, to allow the heat to distribute evenly. Heat only till just hot, not piping hot...or that will toughen the meat just like baking at too high a temp.
The traditional oven method allows you to apply gravy in a nice fashion though, without re-positioning the meat and messing up that beautiful gravy layer on top.
The method Seige suggested is cool too. It's a take on sou vide (Google it if you've never heard of it). If you have a food saver, this is a good way of looking at things. If you don't have a food saver...why don't you?!!!! You can keep meats even for years in some cases in the freezer with a properly done food saver package.
You can use the microwave with food saver packages too! ("There Chef K-Dude goes with that stupid microwave again!"), but the hot water method is more foolproof. You are out of time now, but an ideal way to use the slow cooker would be to do a test-run with the cooker with just water and record what the temps are at each holding temp setting (low-med-high). I did this with a mini slow cooker hoping I could do slow poached eggs with it, but sadly low on that thing was above 145...a nod to the food safety police which you will find very active in here keeping you from yourself, making yourself sick and blaming the website on it.
Slow poached eggs FYI:
http://momofukufor2.com/2010/01/slow-poached-eggs/ (in case the link police strike that, google it...information is a "cat out of the bag" these days)
So with the slow cooker, if you find, say..."medium" holds water at exactly 160°, then that is "theoretically" perfect for Seige's method of taking that turkey in properly sealed food saver bags and covering with water and setting on low and leaving for church on Sunday morning (Or whatever else you might have planned on Easter Sunday mornings!). But! I would leave the packaged meat out of the slow cooker at first (just have the water hot when you get home) and in the fridge till you get home, then allow the foodsavered packaged meat to rest at room temp for maybe 15 minutes, then plop in the 160° pre-heated water till hot. A that point, the meat is ready to eat cold coming out of the fridge anyway, all you are doing is warming it. You can keep it in that 160° water till you are ready to serve.
sou vide holds foods at exact temps until ready to serve. You can take a slice of roast beef and keep it medium for hours. Some of the finest high volume restaurants do this and you never know about it. The "microbe police" might argue about this...and food safety is always first on a web site or any public place that gives advice because they dont know if you are doing things "exactly" at home...just like with canning foods or any other recipe; people will report problems, but when you dig down, they haven't followed instructions "exactly" to a "Tee". Cross-contamination is one of the biggest food borne illness problems, and that has nothing to do with cooking and holding temps usually. People have no idea that washing a chicken for instance actually spreads more bacteria than anything as tiny droplets splash for FEET around the sink...it's actually better to NOT wash poultry or any other meat unless there is debris, brine or a coating that needs to come off...or you have dropped it on the floor! It's hard to get it in the head to go straight from the package to the prep though...it took me years to get that "washing meat" BS out of my head.
How do I know this about sou vide, etc.? I am a metal fabricator. I worked in a shop years ago that made the prototype for Vie de France's facility in Alexandria, VA. I saw the testing and refining of the sou vide tanks and worked on them as they tweaked them to hold various foods at different temperatures. It was a science. We also made prototype vertical electric smokers (think "industrial version of the
masterbuilt units) for entrepreneurs including the late Wilbur Hardee, the founder of Hardees.
Back to the microwave...I use the food saver for a lot of stuff and find the packages hold up to microwaves very well. In fact you can cook stuff to mush like the slow cooker or pressure cooker if you aren't careful and they usually wont explode. I make my own boudin (and have the recipe really close to perfect "real south Louisiana boudin") and seal in food saver packs. Once thawed, all I have to do is hit them in the microwave until just hot enough to enjoy, and BAM! (as Emeril would say) I'm sucking good boudin from the casing!
So thanks to your question Famous, I will be testing my slow cooker and considering portioning some thicker slices of turkey breast for dinners to heat this way...and thanks to Seige for the hybrid idea going right to "sou vide".
Or I might just microwave them! But! Still, slow and low would be the key on meats like turkey, even in a food saver bag.
So, back to the basics:
While the slow cooker may work, you wont know what temps you are heating to while you are gone and that's where the food-borne illness or turning the meat to "mush" might happen. If you get the meat to "mush" you probably wont have food borne illness because it got hot enough. But, holding the meat from cold to just at 160° for hours on-end, could grow "Herman the Vermin" like Jimmy said. Using sou vide, that doesn't happen, but still best to bring the water temp up first rather than start from cold, then drop the packages in when the water is hot.
I think the best time to cut and portion the turkey breast for dinner thick slices is right after resting. This is a good time to foodsaver for that kind of portion cuts too.
I think I will do that with one side of the breast of mine, then I will refrigerate the other half for thinner slices for lunch-meat. Meat slices better on an electric food slicer much easier after refrigeration when it is cold and "set-up". This is partially why many folks will tell you to refrigerate a pastrami smoke before thin slicing, but you can eat it after resting right out of the box...but plan on slicing it thicker...usually...if it will even stay together without crumbling.
Let us know how you did Famous!