It’s best to thickly grate your zucchini when you’re making zucchini bread. I know it’s tempting to peel the skin but you should actually leave it on because it’s full of healthy vitamins and minerals. It also contributes to the texture and adds a nice color to the bread once it melts in.
Try to pick up a smaller zucchini if you can, around 8 to 10 inches long, because the larger zucchini tend to be quite dry and bitter. How you choose to grate it really depends on what kitchen equipment you have available. If you’re grating a small amount, then a cheese grater will work perfectly. But if you’re grating a larger amount of zucchini, it’s probably better to use a food processor that’s fitted with a grating disk.