Updated: Jan 29, 2020
A good sharp knife is a cook’s best friend. It will help you to work with precision, and quickly. A dull knife conspires against you and slows you down.
And here is another reason for keeping that knife sharp: It makes your food taste better (and look better, too).
Fresh herbs will release more of their aromatic oils beneath a knife’s sharp blade. A tomato slice or wedge, instead of looking trod upon, will retain its luscious juices with elegance. Carefully hand-cut onions are easier to brown because they stay drier than onions that have been bludgeoned into slices. (A blunt instrument smashes cells, which causes moisture to accumulate, whereas a sharp blade glides through with ease.)
Steak tartare has superior texture and flavor if you use a sharp knife instead of a meat grinder. Instead of being sadly hacksawed, a roasted bird or loin of pork is a delight to carve. A good knife doesn’t have to be expensive (and an expensive knife is useless if it isn’t sharp). You really need only a few knives anyway: a paring knife, an all-purpose vegetable knife, a long so-called chef’s knife. A proper serrated bread knife helps enormously, and not just for bread. And though it is not a knife per se, a sharp swivel-type vegetable peeler is essential.
The knife I find most useful is a vegetable knife, with a blade about 2 inches wide and 7 to 8 inches long. I prefer a square-edged Japanese-style, but a European style with a pointed end is fine too. This type of knife does everything: slice, dice, chop, mince.