Walnut

Let me tell you about the walnut, and why so many people buy a bad one without knowing it.

Before it gets to your bowl, a walnut sheds its outer green husk, then you crack the hard shell underneath, and inside that, the kernel wears one more layer: a thin, papery skin. Bite into that skin alone and your mouth puckers, dry, the way it does after a cup of strong black tea left too long. That's the walnut's own bitterness, and it belongs there. Once the shell is cracked, the kernel starts to change — walnut oil is generous, more than half the kernel's weight, and a cracked walnut doesn't keep for long once it's open to the air. Rancid oil smells sharp, almost like old paint. A fresh kernel smells mild, faintly sweet, almost milky.

So choose by nose first, not by size or shade — let the smell decide. Press one between your fingers: it should feel firm and dry, not soft or oily to the touch. If it feels greasy, smell it before you trust it.

Some people say bitterness always means a walnut is unripe. No! The skin itself is bitter, even in a perfectly good nut. But a rancid walnut tastes bitter too, so don't wave the bitterness away without checking the smell first. The mistake this leads to: people peel the skin off to "sweeten" the nut, losing part of what makes a walnut a walnut, without actually fixing a rancid one.