To blanch zucchini, follow these steps:

1. Wash the zucchini thoroughly and cut it into slices or desired shapes (commonly ½-inch slices).
2. Bring a large pot of unsalted water to a full rolling boil.
3. Place the zucchini in a blancher basket or a wire basket and dip it into the boiling water. Start timing immediately.
4. Blanch the zucchini for about 1 to 3 minutes (typically 3 minutes for slices, 1-2 minutes for smaller or grated pieces), until the zucchini turns bright green but remains firm.
5. Immediately remove the zucchini from boiling water and plunge it into a large bowl of ice water (60°F or below) to stop the cooking process. Let the zucchini cool in the ice water for at least 3 minutes.
6. Drain the zucchini well and pat dry with a towel or use a salad spinner to remove excess water.

This blanching process stops enzymes that cause spoilage, helping zucchini retain its color, texture, and nutrients, especially useful when freezing zucchini for later use.