Oranges and grapefruits bring fresh, zesty bursts of flavor, fragrance and color when Wisconsin’s produce still lies dormant. What’s more, the beauty of citrus runs so much more than skin deep.

With more than 2,500 types of citrus worldwide, it would be a shame to limit your larder to lemons and limes. Luckily, many grocers also stock seasonal stunners like Sumo mandarins, yuzu, and pomelos.

Slice the top and bottom off one of the grapefruits. Stand it up on a cut side and, using a small sharp knife, slice off the peel and pith, following the curve of the fruit. Save the peels (there ...