Most cut vegetables keep 3–4 days in a sealed container. Cutting exposes
the flesh to air and to whatever was on the knife and board, which starts a clock that a whole
vegetable does not have.
How long each one lasts
| Cut vegetable | Fridge |
|---|---|
| Carrots, sticks or slices | 4–5 days |
| Celery | 4–5 days |
| Peppers | 3–4 days |
| Onion, chopped | 3–4 days, sealed |
| Cabbage, shredded | 3–4 days |
| Leafy greens, chopped | 2–3 days |
| Cucumber | 2 days |
| Mushrooms, sliced | 1–2 days |
| Tomatoes | 1–2 days |
| Potatoes, peeled | 1 day, in water |
| Avocado | 1 day |
What is worth prepping ahead
The top of that list. Carrots, celery, peppers, onion and cabbage all keep
three to five days cut, which makes a Sunday hour genuinely useful.
The bottom four — tomato, cucumber, mushrooms, avocado — should be cut on the day.
Prepping them ahead saves nothing and costs texture.
Peeled potatoes go under water
Otherwise they oxidise and grey within the hour. Cover completely with cold water,
refrigerate, use within a day — longer and they leach starch and cook watery.
Onion and garlic need a real lid
Not for their own sake — they keep well — but because they will flavour everything else
in the fridge, including butter and milk. A box with a proper lid, not cling film.
And do not refrigerate whole tomatoes at all
Cold destroys the flavour and turns the flesh mealy. Once cut they have to go in,
and then they keep only a day or two — which is an argument for cutting them last.
Elsewhere in the guide:
How long does salad last in the fridge ·
How long do peeled potatoes last in the fridge ·
How long does cut lemon last in the fridge ·
Why onions make you cry