Red radishes are, as a general rule, hotter. Long varieties have a milder flavor.
Look for nice unwilted green leaves, a sign of freshness.
The radishes should be firm, smooth and brightly-colored. Avoid large radishes, which may be hotter, hollow or dehydrated.
Avoid radishes that feel spongy or look shriveled.

 

Cut off most of the tops, leaving a little green; trim the root. Refresh under running water.

Remove all the green part. Slice the tops of the radishes into quarters, then soak in lightly salted ice water for 30 minutes: the quarters will open up nicely like petals.

Revive radishes that have lost their crunch by immersing them in ice water for an hour or two before serving.
 

Radishes are usually eaten raw with a sprinkling of salt. Try using sea salt or fleur de sel.

Chopped into very fine dice and combined with vinaigrette, they give even more crunch to a salad.

In thin julienne strips, they enliven Asian-style stir fries and make a nice substitute for water chestnuts. Add them at the last minute, because radishes don’t stand up to long cooking.
 

Don’t discard the radish tops! They make a wonderful soup.