Quick Answer
It is generally recommended to cut the root off an onion before using it in recipes. The root end tends to be tougher and more fibrous than the rest of the onion. Removing it helps ensure more even cooking and a better texture in dishes. However, the root does not necessarily need to be cut off every time. For applications like roasted whole onions, the root can be left on.
Should You Cut the Root Off?
Cutting off the dry, woody root end of an onion before chopping or slicing it is a common practice in cooking. Here are some of the main reasons it is usually removed:
To Avoid a Tough, Fibrous Texture
The bottom root end of an onion is often very fibrous and chewy in texture. This portion has a higher concentration of the fibers that run vertically through an onion. Leaving the root on can lead to unpleasant tough or stringy pieces in the final dish. Removing it ahead of time avoids this textural issue.
To Allow for More Even Cooking
Since the root end is denser, it can take longer to cook through than the rest of the onion. Cutting it off lets the onion cook evenly all the way through. If the root is left on, you may end up with some undercooked pieces in the center.
For Easier, Uniform Slicing and Chopping
The root narrows to a point, which can make slicing or chopping the entire onion tricky. Cutting it off creates a flat, even surface on the bottom of the onion. This allows for simpler, uniform cuts.
To Reduce Strong Flavors
The concentrated, woody fibers in the onion root contain more of the sulfuric compounds responsible for onion’s pungent, tear-inducing effects during cutting and cooking. Removing this portion can make the flavor slightly milder.
When You Can Leave the Root On
While usually ideal to cut it off, there are some cases where leaving the onion root intact is acceptable or even preferable:
When Roasting Whole Onions
Whole roasted onions are left with root and stem ends so they hold their shape. The interior cooks through gradually while roasting.
In Onion Soups and Stocks
Onion roots add flavor and nutrients when simmered in soups, stocks, and broths. The long cooking time softens the texture.
For Onions Cooked Entirely Whole
Onions braised, caramelized, or grilled whole do not require root removal. The layers soften up during thorough cooking.
In Onion Powder or Other Dried Forms
Dehydrated onion powders and flakes utilize the entire onion, including the root. The drying process makes the texture uniform.
When Using Up Scraps
Leftover onion bottoms and scraps work fine for flavoring stocks or any recipe where small pieces get cooked down.
Tips for Prepping an Onion
Here are some recommendations for prepping an onion to cook with:
– Cut off the dry, scraggly root end first. Do not discard – the root can be frozen and used for stock.
– Leave the papery outer layers on until you are ready to chop or slice the onion. The skin helps hold the layers together.
– Rinse or wipe down the onion if visibly dirty. Pat dry before cutting.
– Trim off the stem end, leaving the core intact if cooking the onion whole. For chopped/sliced onion, cut the stem off flush with the top.
– Peel off any loose, papery outer layers. Rinse or wipe again if needed.
– Cut the onion in half lengthwise through the root and stem end. Place flat side down on cutting board.
– Remove the papery outer layers. Try to leave at least one layer on for chopped onion to hold it together.
– For chopped/sliced onion, make parallel cuts top to bottom, then horizontal cuts across. Keep root end intact while slicing for easier handling.
– For diced onion, stack slices and make perpendicular cuts through the stack.
– Chopped onion can then be separated into individual pieces. Discard dry outer layers and root.
Onion Chopping Techniques
There are a few different techniques that can be used to chop an onion.
The Standard Dice
This technique involves:
1. Cutting the onion in half from root to stem end
2. Peeling off the outer layers
3. Making several vertical slices
4. Cutting crosswise to dice
The Wedge Technique:
1. Cut off both ends of the onion
2. Peel off outer layer
3. Keep root end intact and make 4-5 vertical cuts to the root
4. Make horizontal cuts to create wedges
5. Separate wedges and dice if smaller pieces needed
| Chopping Method | Description |
|---|---|
| Standard Dice | Cut onion in half, peel, slice top to bottom, then cut crosswise |
| Wedge Technique | Remove ends, peel, make vertical cuts keeping root intact, cut across wedges |
Using a Food Processor
A food processor quickly and evenly dices or chops onion with no tears.
1. Remove ends and peel onion
2. Cut in large chunks to fit feed tube
3. Pulse with bursts until desired fineness
Be careful not to overprocess into a paste.
Onion Chopping Tips
– Use a sharp knife to slice cleanly through the onion layers.
– Remove papery outer layers only when necessary to avoid onions falling apart.
– Chill onions in the refrigerator for 30 minutes before cutting to reduce tearing.
– Use the root end to hold slices together while cutting.
– Cut the root end off last once the pieces are chopped.
– Keep your face clear of the cutting board to avoid overwhelming tear-inducing vapors.
How Finely Should Onions Be Chopped?
How finely to chop onions depends on the dish and cooking time:
| Onion Chop | Good For |
|---|---|
| Coarse chop | Onion soups, stocks, long braises |
| Medium dice | Sautéed onions, salads, pastas |
| Fine dice | Quick sautés, stir fries, well incorporated dishes |
| Minced | Delicate sauces, fillings, finely mixed dishes |
Onions for roasted vegetables or on a burger can be cut into thick slices or wedges. Finer mincing makes onions cook faster and more evenly.
Do Onions Need to Be Soaked After Chopping?
Some people recommend soaking freshly chopped raw onions in water before using them to remove harsh, tear-inducing compounds. However, experts generally agree this is unnecessary and not beneficial:
– Draining off the sulfuric compounds can affect onion’s flavor in finished dishes. Onions may taste more bland.
– Onions add moisture to dishes already. Soaking makes them waterlogged.
– Acids like lemon juice or vinegar, not water, counteract the tear-causing enzymes.
– Compounds that cause tearing are only released when cell walls are damaged. Keeping cut onions intact prevents this reaction.
– Browning chopped onions in oil breaks down the tear-inducing chemicals.
Instead of soaking, store chopped onions in an airtight container in the fridge up to 5-7 days. Freeze if keeping longer.
Can You Chop Onions in Advance?
It is possible to chop onions a day or two ahead:
– Prep onions as close to cooking as possible for the freshest flavor.
– Chop onions and store in an airtight container in the refrigerator. Leave intact as much as possible.
– Avoid soaking or rinsing chopped onions, which dilutes flavor.
– Use within 3-5 days for best quality and to avoid spoilage.
– For longer storage, spread chopped onions in a single layer on a baking sheet and freeze. Then transfer to a freezer bag.
– Frozen chopped onions can be stored 6-8 months. Thaw before using.
Chopping onions just before cooking brings out the most flavor, aroma, and benefits. But advance prep can be handy for busy schedules.
Onion Chopping Safety Tips
When chopping onions:
– Use a sharp knife to reduce injury risk.
– Keep fingertips curled in to avoid cutting yourself.
– Avoid distraction and give the process your full attention.
– Cut away from your body.
– Work carefully and avoid rushing.
– Store knives safely in a block when not in use.
– Wash and dry hands before and after contact with raw onions.
– Wash cutting boards, knives, and prep surfaces after use.
– Refrigerate cut onions within 2 hours of prep.
– Follow additional food safety practices for safe onion handling.
Conclusion
Removing the dry root end of an onion before chopping or slicing is generally recommended. The root contains tough, woody fibers that do not soften well during cooking. Cutting it off allows for more even cuts, cooking, and textural quality. However, the root can be left on whole onions or in dishes with extended cooking times where the fibers soften. With proper knife skills and safety practices, onions can be quickly prepped to add flavor, nutrients, and versatility to recipes.