Amongst other things, I'm making a chocolate & bourbon pecan pie for Christmas in my capacity as family pastry chef. The recipe calls for toasted pecan halves.
What is the best way to toast nuts evenly? I assume a low oven is best to avoid scorching, but what temperature and for how long?
An oven is the way to go.
Toasting on a frying pan is a pain because you have to stand there shaking it for so long and it is far to easy to scorch if you pause.
I have seen some recipes call for low oven temps but I use 350F (175C) for 10 to 15 minutes stirring a few times. Some sources online recommend as low as 5 minutes but I personally have not ever had them done that quickly. They still have to be checked or they will burn.
I like to use my toaster oven because it heats up faster and is cheaper to run.
I have used an air popcorn popper with good results. Don't overfill it and remove them when they smell nutty. It goes very fast but you have to do them in batches if you have many.
For a pie or other sweet applications, I like to toss the nuts in butter and brown sugar and let them candy in the oven. The fat makes it harder to burn them. Obviously this won't fit for all recipes.
I personally have not had good results using the microwave. Some people swear by it but it seems to me to make them a little gummy.
My recent experience with nut-toasting gave a temperature and time recommendation with the following added advice: " . . . until fragrant"
That made a world of difference because in my case (almonds), it took several minutes longer than the stated time and it was definitely worth the wait. The cookies made from the toasted almonds were voted best of the cookie exchange.
While ovens, cookie sheet materials and nut piece size and shape may vary, the "until fragrant" tip was something I can depend on (assuming I do not have a stuffy nose!)
I go with an oven, but at 250 degrees. And my experience with toasting all nuts is that they can go from toasted to burnt very quickly, so check on them and remove promptly once toasted.
Just a couple more tips
oven toasting in a preheated dark heavy skillet evens out the toasting.
single layer with no corners (they burn first). Ideally, a donut shape on pan: the center ones get plucked out and moved to edges
under grill (UK) or broiler (U.S.) gives a much more accurate visual sign of browning vrs the black-on-the-bottom bottom heat. Just watch through glass front with door cracked open for sniffing.
I only toast one side as they are fairly flat and that seems enough toasty flavor for further baking.
