Toasted nuts almost always taste better than untoasted nuts, whether you’re eating them as-is or incorporating them into a recipe. They have a crisper texture and a more pronounced nuttiness, with less of the vegetal notes that some raw nuts can have. Toasting hazelnuts makes them especially delicious because it gives them a much better texture and brings out a butteriness that compliments their nuttiness well. Toasting them also has the advantage of makes their skins very easy to remove.
Hazelnuts have some of the most tenacious skins of any nut. They’re very difficult to remove, which is why skinned hazelnuts always command a premium over unskinned nuts. Most recipes for hazelnuts call for skinned nuts because baked goods generally look better when they’re not full of brown flecks of un-skinned nuts (and, for many, the nuts simply taste better that way), though it won’t hurt a quick bread or cookie recipe to use the nuts with their skins in place.
How to Roast Hazelnuts: Preheat oven to 250F. Place hazelnuts on a large sheet pan. You can line it with aluminum foil (I usually do), but it is not necessary to prepare the pan in any way. Roast the nuts for 30-35 minutes, stirring every 10 minutes or so, until they are a light golden color. The skins will be slightly loosened.
To check for doneness, take a nut and allow it to cool slightly. Break it in half and look at the interior: the hazelnut should be evenly toasted throughout and should not have a white/light colored ring in the center. If it does, that means your nuts are not completely toasted. Simply pop your nuts back in the oven for an additional 5-10 minutes and re-check. Allow the nuts to cool completely before using or storing.
A longer, lower roasting time means that the nuts will toast more thoroughly, so they will not be toasted on the surface while remaining raw inside. A longer roasting process is also the best way to loosen as much of the skin of the nut as possible.
To Remove the Hazelnut Skins: When you toast your hazelnuts, water and oil are released from the nut and, as they make their way to the nut’s surface, the thin brown skin enveloping the nut is loosened. To remove it completely, take your toasted nuts and place them in a large, clean dish towel. Rub the nuts vigorously with the towel and the skins (the vast majority of the skins, anyway) will be left behind, stuck in the towel.
If you have a few bits of skin remaining, you can repeat the rubbing process with a second towel, or simply chop off any unsightly bits with a small, sharp knife if you really need your nuts to be as pristine as possible.