Purple Root Vegetable Identification: Beetroot, Radish or Something Else

The families, and why it matters

The colour is a red herring

The purple in beetroot, purple carrot and purple yam comes from betalains and anthocyanins, which are different pigment families entirely. That is why beetroot stains so badly and purple carrot stains much less. It is not about how dark the vegetable looks.

So do not use colour as your main clue. Use the shape of the root, the way the leaves attach, and the family.

The features to look at

• Shape. Beetroot is round to flattened with a rough, often hairy surface. Carrots are long and tapered. Radishes are small and round or elongated. Turnips are round with a distinct flat top where the leaves were cut. Kohlrabi is a swollen ball with leaf stalks radiating from the sides like spokes.
• The top. Beetroot and silverbeet have broad, dark green leaves with red or purple veins and red stalks. Carrots have feathery, finely divided leaves. Turnips and radishes have rough, lobed leaves with a hairy texture.
• The cut surface. Beetroot has distinct concentric rings of darker and lighter red. Carrot is uniform with a paler core. Radish is white inside unless it is a specific red-fleshed variety. Purple yam is creamy white with purple flecks.
• The smell. Beetroot smells of earth and iron. Radish smells sharp and peppery. Carrot smells sweet and faintly of carrot, which sounds obvious but is instantly recognisable.
• The feel. Beetroot is hard and heavy. Radish is crisp and light. Kohlrabi is lighter than it looks and snaps like a green apple.

Raw or cooked, and how badly it stains

Almost every root vegetable on this list can be eaten raw, and most are better for it at a young size. The exceptions matter: raw purple yam and raw cassava must be cooked, and any root that has gone soft, sprouted or mouldy should be discarded.

Staining is the other practical thing. Beetroot will dye your hands, your board, your tea towel and whatever it touches. Purple carrot stains lightly. Purple yam stains moderately. Wear gloves for beetroot if you care about your hands, and use a plastic board rather than a wooden one.

A trick that helps with beetroot: rub your hands with salt and then wash with soap, or use lemon juice. It lifts the pigment much better than soap alone.

What I cook with each

Beetroot goes in the oven whole, wrapped in foil, for about an hour, then the skin rubs off with a paper towel. It also goes raw into a mandoline salad with orange and mint, which is much better than it sounds.

Purple carrot I treat exactly like an orange carrot. Roasted, it keeps its colour and sweetens, and it makes a striking purée without the bleeding that beetroot gives you.

Radishes I only ever eat raw. Cooked radish is a different, much duller vegetable, and roasting them mostly wastes them.

Turnip and swede I roast hard and mash with butter, which is where the sweetness finally shows up. Kohlrabi I slice thin and eat raw with salt, like an apple.

I pulled what I was certain was a beetroot out of the garden, roasted it whole with the others, and served it to guests. It was a purple carrot. It was fine, but it was not the dish I had planned.

The confusion is understandable. Purple roots all share the same deep colouring, and the colouring comes from the same pigments, so they look related. They are not. Beetroot is in the same family as silverbeet. Radish, turnip and kohlrabi are all brassicas. Carrot and parsnip are umbellifers.

Getting the family right is what separates them, and it tells you how they will cook before you commit.