How to Grate an Onion in 3 Easy Steps

One of the most efficient ways to get small, fine onion pieces that cook quickly is to grate them. Grating a raw onion involves shaving it down into very small slices that you couldn’t achieve with a dice or even a very fine mince. This process allows you to create small onion pieces that caramelize quickly and evenly, rather than chopped onions or diced onions which you’ll usually need to precook before incorporating into a sautéed mixture. Using grated onion is perfect for infusing dishes like meatballs, meatloaf, and various gravies with a strong, savory onion flavor.

The best way to grate an onion is with a grater, though a food processor is also acceptable. Follow these steps to grate an onion using a box grater or cheese grater:

1. 1. Peel: Remove all of the outer peel from the whole onion. If the sulfoxides from the onions are bothering you to tears, place the onion in the freezer or soak it in cold water before cutting.
2. 2. Slice: Using a sharp knife, slice the onion in half, cutting vertically from root to stem. Trim off the very top of the onion or the stem end. Keep the root of the onion intact; you’ll hold the root onto as you grate the onion.
3. 3. Grate: Stand your grater upright and place the cut top end of the onion against the grater. Holding onto the cut end (or root) of the onion, shred the onion against the grater in a back and forth motion. You can grate the onion down to the basal plate nub.

If you don’t have a grater or need to grate multiple onions in a short period, use the shredding function on your food processor. Note that overprocessing your onion can leave you with a liquidy pulp that is more juice than onion. Follow these steps to grate an onion using a food processor.

1. 1. Peel: Remove all of the outer peel of the onion. If your eyes are sensitive to sulfoxides, place the onion in the freezer or soak it in cold water before cutting.
2. 2. Slice: Place your onion on a cutting board and slice off the stem and root. Next, cut the onion into quarters.
3. 3. Process: Using the shredding attachment, feed each piece of the cut onion into the food processor, only using the blades as needed to achieve the desired texture. If possible, use the “pulse” feature rather than just letting the food processor run.
4. 4. Drain: If you have lots of extra onion juice left over after the shredding process, place the grated onions into a cheesecloth and squeeze out the excess moisture.

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