Why Do Pears Ripen From the Inside Out? (And How to Tell)

Why Do Pears Ripen From the Inside Out?

Pears ripen from the inside out because of how their flesh develops and because of a quirk in how they handle ethylene, the ripening hormone. Unlike most fruit, which softens from the skin inward, a pear softens starting at the core and working outward. By the time the outside feels soft to the touch, the inside may already be overripe or even brown. This is why pears are so notoriously difficult to judge for ripeness and why so many people end up with mealy, brown-centred pears despite their best efforts.

The pear is a climacteric fruit, which means it continues to ripen after harvest, producing ethylene gas that drives the softening and sweetening process. But unlike a banana or a tomato, which ripen fairly evenly throughout, a pear's core tissue responds to ethylene faster than the outer flesh. The result is an inside-out ripening pattern that catches people off guard.

The Core Reacts First

The cells in the pear's core — the area around the seeds — have a different structure and metabolism from the cells in the outer flesh. Core tissue is denser, has less air space, and has a higher rate of respiration. When ethylene triggers the ripening cascade, the core cells break down their starches into sugars and soften their cell walls faster than the outer flesh cells. This means the inside becomes soft and sweet while the outside is still firm.

This is different from most other climacteric fruit. An apple, for example, ripens more evenly because its core and flesh tissue are more similar in structure and respiration rate. A banana ripens from one end to the other but fairly evenly through the flesh. A pear's distinctive inside-out pattern comes down to the structural difference between its core and its cortex tissue. The same structural difference is why a pear feels gritty when you bite into it — those gritty bits are sclereids, specialised stone cells concentrated in the flesh, and they are more common near the core. See our pear browning guide for what happens when that tissue oxidises.

Why Pears Need Cold Storage Before Ripening

Many European pear varieties — particularly Bartlett (called Williams in Australia) and Beurre Bosc — have an unusual ripening behaviour: they need a period of cold storage before they will ripen properly at room temperature. If you pick a Bartlett and leave it at room temperature immediately, it may stay hard and never develop proper flavour and texture. If you cool it for a few weeks first and then bring it to room temperature, it ripens into the buttery, sweet pear you expect.

This is a commercial consideration too. Most Australian pears are stored at low temperatures after harvest, then brought out for retail as needed. The cold storage acts as a "pre-conditioning" that allows the ripening process to proceed normally later. This is why pears at the supermarket are often rock-hard — they have been in cold storage and need time at room temperature to ripen. See our pear season guide for which varieties are available when.

How to Tell When a Pear Is Ripe

Because pears ripen from the inside out, the traditional "squeeze the whole fruit" test is misleading. If the body of the pear feels soft, the inside is probably already overripe. The correct test is to press gently near the stem end — the narrow part at the top. This area gives an early indication of ripeness because it is thinner and shows the internal softening sooner. When the stem end yields slightly to gentle pressure, the pear is ripe. If the body is soft but the stem end is firm, the pear is overripe outside and still ripening inside — a messy state.

Colour is a less reliable indicator. Some varieties (like Bartlett) change from green to yellow as they ripen, but others (like Beurre Bosc) stay the same colour throughout. For Packham pears, a slight colour change from bright green to yellow-green is a hint, but the stem-end test is more reliable. Scan the pear with PickFresh if you want an objective ripeness assessment.

How to Ripen a Pear Properly

If you have bought hard pears and want them to ripen, the best approach is to leave them at room temperature for a few days. Pears produce ethylene, so putting them in a paper bag with a banana or an apple speeds up the process — the extra ethylene from the banana triggers faster ripening. See our ethylene guide for more on this technique.

Once a pear is ripe — when the stem end yields to gentle pressure — you can slow further ripening by putting it in the fridge. A ripe pear will hold in the fridge for 3–5 days. Do not put an unripe pear in the fridge hoping it will ripen later — cold stalls the ripening process, and a pear that has been chilled before ripening may never develop proper texture. See our storage guide for the full rules.

Why Pears Go Brown at the Centre

The inside-out ripening pattern has an unfortunate consequence: by the time you notice a pear is soft on the outside, the core may have already started to brown and go mealy. This browning is oxidation — the same enzymatic reaction that makes cut apples go brown and avocado go brown. The cells at the core break down first, release their enzymes, and oxidise the phenolic compounds in the tissue. The result is a brown, soft, sometimes gritty centre that tastes stale even though the outside looks fine.

This is not dangerous to eat, but it is unpleasant. The fix is to catch pears earlier — eat them when the stem end just starts to yield, not when the whole fruit is soft. A slightly firm pear is far better than a brown-centred soft one.

Pear Varieties and Their Ripening Behaviour

Different pear varieties ripen differently:

• Bartlett (Williams): The classic canning pear. Ripens quickly and goes from firm to soft in a day or two. Most prone to the inside-out problem.
• Beurre Bosc: A firmer, denser pear with a russeted skin. Ripens more slowly and holds its texture better. Less prone to brown centre.
• Packham: The most common Australian pear. Large, green, and sweet. Ripens at a moderate pace — check the stem end daily.
• Nashi: A round Asian pear with crisp, apple-like texture. Does not soften the same way — it is eaten crisp, like an apple, and does not have the inside-out ripening problem.
• Corella: A small, red-blushed pear with a firmer texture. Ripens slowly and holds well.

For eating raw, Nashi pears are the easiest — they stay crisp and you do not have to worry about the ripening timing. For the classic soft pear experience, Beurre Bosc is the most forgiving because it ripens slowly and evenly. See our pear varieties guide for more detail on each variety.

The Takeaway for Pear Lovers

The inside-out ripening of pears is a quirk of their biology, and once you understand it, pears become much easier to enjoy. Check the stem end, not the body. Ripen at room temperature, then refrigerate once ripe. Eat slightly firm rather than waiting for full softness. Buy varieties that ripen slowly if you want a wider window. With a bit of practice, you can hit the perfect pear — sweet, aromatic, just soft enough — far more reliably than by squeezing the whole fruit and hoping.

Australian pears are available from February to October, with different varieties peaking at different times. Check our pear fibre guide for the nutritional breakdown, and scan your pear with PickFresh for a freshness check before you buy.