How long do lemons last before they go bad?

The short version: a lemon left out in a fruit bowl is usually fine for about a week before it starts to soften and dry out. The same lemon in the fridge, ideally in the crisper drawer, can hold up for three to four weeks, sometimes longer. That gap is bigger than most people expect from a single piece of fruit sitting in a bowl, and almost all of it comes down to one thing a lemon does not do that an apple or a banana does.

Why a lemon does not behave like an apple or a banana

Some fruit keeps ripening after it is picked. Apples and bananas are climacteric, meaning they carry on converting starch to sugar and softening off the tree, driven by a burst of ethylene gas that builds inside them over time. That is why a hard green banana on the counter turns soft and sweet within days.

Citrus does not do this. Lemons are non-climacteric: once picked, they are essentially as ripe as they are ever going to get, and they do not throw off meaningful ethylene the way an apple does. Nothing is quietly finishing on the inside the way it is with a stone fruit or a banana. What happens to a lemon after picking is not ripening at all — it is a slow, one-way loss of the moisture sealed inside that thick, waxy peel, and that peel is a genuinely good barrier, which is the whole reason a lemon lasts so much longer than a berry or a soft summer fruit in the first place.

What actually decides how long it keeps

Because a lemon is not racing a ripening clock, the fridge does something different for it than it does for an apple. It is not slowing down internal decay so much as it is slowing the rate at which moisture escapes through the peel. A warm, dry counter pulls water out of a lemon faster than a cold, humid crisper drawer does, which is the entire explanation for why the same piece of fruit can look plump after a month in the fridge and shrivelled after ten days on the windowsill.

This also means storage matters more than variety, ripeness at purchase, or anything else about the individual lemon. A loosely closed bag or a lidded container in the crisper slows moisture loss further still, because the lemon is no longer drying out into the open air of the fridge itself. None of this is about keeping bacteria away — it is about keeping water in.

A cut lemon runs on a completely different clock

Everything above describes a whole, unbroken lemon. The moment you slice one, that thick peel stops doing its job, and the exposed flesh is now open to air and whatever else is in the fridge around it. A cut lemon, wrapped or in a sealed container in the fridge, is realistically good for a few days rather than weeks — the flesh dries out at the cut face, and eventually mould can take hold there in a way it almost never does on an intact peel.

Juice and zest each have their own, more forgiving lives once separated from the fruit. Fresh-squeezed juice keeps in the fridge for about a week in a sealed container. Both juice and zest freeze well — juice in an ice cube tray, so you can pull out one lemon's worth at a time, and zest in a small bag or container — which is the better move for the second half of a lemon you only needed for its juice, rather than leaving the cut half to dry out in the door.

Reading a lemon honestly

A lemon changes in ways that look worse than they are, and in ways that are a genuine reason to stop.

• A slightly wrinkled or softening peel. This is moisture loss, exactly as described above, not spoilage. The lemon still has juice in it, even if it is a little harder to get out — it is simply past its best for zesting or serving in wedges.
• A peel gone hard and noticeably lighter, with very little give. The lemon has dried out significantly. It may still yield some juice, but it is well past the point of being worth keeping much longer.
• Soft, dark, sunken patches, or flesh that has gone mushy and discoloured. This is the fruit actually breaking down internally, not just losing water at the surface. That is the point to stop, not season to taste and continue.
• Any fuzzy white, green or blue-grey mould. Discard the whole lemon rather than cutting around the spot. Citrus is soft and moist enough under the peel that mould can spread into the flesh well beyond what is visible from outside, which is not true of a firmer fruit like an apple.

The part that is easy to lose track of is not any of this — it is simply noticing a lemon is still there at all. A lemon usually enters a kitchen for one recipe that needed the juice of half of it, and the other half, or a second lemon bought "just in case," ends up pushed to the back of the fruit bowl or a crisper drawer, quietly drying out for a month before anyone remembers it exists. Munch logs a batch against the day it came home and where it is stored, so a lemon bought three weeks ago does not blend into one bought yesterday, and it turns up in what the household can already cook tonight rather than being rediscovered, shrivelled, long after it was any good.

None of this needs a rule for every stage a lemon passes through. It needs one distinction: a lemon does not ripen on you the way a banana does, so a wrinkled peel is not a countdown running out — it is water leaving a fruit that would otherwise just sit there, and the fridge is the one place that slows that down.