Hazelnuts (filberts): Hazelnuts or filberts are sweet, rich, grape-sized nuts. These nuts have a bitter brown skin that is best removed by heating them at 350°F. for 8 to 10 minutes until the skin begins to crack and flake. Place a handful of warm nuts between layers of clean dish towels and rub vigorously to remove the skins.
Hazelnuts are usually packaged whole. They are used whole, chopped or ground in all manner of sweets, and for texture and flavor in some main dishes and salads.