Aubergines are easy to buy badly. One looks glossy and handsome, but the flesh is spongy, the seeds are tough and the finished dish drinks far too much oil. Another looks modest in size and cooks into the soft, silky texture you were hoping for.
The best choice is usually a firm, heavy-feeling aubergine with smooth glossy skin, a fresh stalk and no soft damage. Size matters less than maturity and variety. In UK shops 'aubergine' and the American term 'eggplant' describe the same vegetable.
Look for fresh glossy skin
On a standard purple aubergine, an even glossy surface is an encouraging sign. UC Davis notes that firmness and external glossiness are associated with the desirable immature harvest stage before seeds become excessively large or hard.
Dull skin alone does not prove poor quality, especially with a variety that is naturally matte, but pronounced wrinkles often mean the fruit has lost moisture. Deep creases and sagging texture are not what you want for a fresh purchase.
Inspect the full surface rather than the side presented in the display. Bruised sections may be hidden underneath, particularly if several aubergines are stacked in a narrow crate.
Check its firmness without damaging it
An aubergine should feel fairly firm and spring back from gentle pressure. A mild response is normal; deep thumbprints or mushy patches suggest deterioration.
Hold it in your palm instead of pinching the skin. Heavy squeezing can leave a bruise in the pale flesh, which becomes more obvious when the aubergine is cut.
The fruit should feel reasonably substantial for its size. A very light, shrivelled aubergine may have lost moisture, but comparing different varieties by weight is less helpful than comparing similar ones.
Inspect the stalk and calyx
The leafy cap around the stem is called the calyx. It should look relatively fresh and secure, not slimy, heavily mouldy or completely dried and collapsing.
Be careful: some aubergine varieties have small prickles on the calyx. Pick the fruit up by its body rather than grabbing the stem tightly.
A dark dry stem cut is not automatically a problem if the fruit itself is fresh. The more important warning signs are wet decay, unpleasant smell or deterioration spreading from the cap into the flesh.
Small or large: which tastes better?
Aubergines are normally harvested before their seeds mature completely. A young fruit often has tender flesh and less developed seeds. That does not mean all small aubergines are better or that large ones are inevitably bitter.
A large globe aubergine may be ideal for thick roasted slices, while a long slender variety suits quick stir-frying. Different cultivars naturally grow to different sizes. Compare within a variety rather than insisting on one perfect diameter.
For a dish where the skin remains visible, smooth and intact skin is helpful. For a dip where everything will be roasted and scooped out, flavour and sound flesh matter more than an elegant shape.
Understand the different varieties
Common UK shops sell dark purple globe aubergines, but you may also find striped, white, round or long narrow types in specialist grocers. Some are better for stuffing and others cook quickly in a hot pan.
The word 'eggplant' does not guarantee a purple fruit. White and striped varieties are genuine aubergines, not unripe purple ones.
If a recipe is written for long Asian aubergines, a large globe aubergine may need cutting differently and a little more cooking. Buy the type that suits the dish when possible.
What about bitterness and salting?
Older recipes often recommend salting every slice to remove bitterness. Modern commercial varieties are frequently milder, so salting is not always necessary for flavour.
Salting can still be useful to manage moisture in some preparations. Sprinkle sliced aubergine lightly, let it rest according to the recipe, then pat it dry. Avoid adding salt indiscriminately if the finished dish already contains salty cheese or sauce.
A very mature aubergine with hard seeds may have a less pleasant texture. No amount of salting turns damaged or rotten produce into good ingredients.
Avoid these signs of damage
Reject fruit with wet sunken patches, broken skin, obvious mould or a sour smell. Dry superficial scratches can be harmless, but a puncture through the surface is a different risk.
Look for extensive browning under the calyx and soft spots where the aubergine has been compressed. An aubergine with large yellowish patches may be ageing or belong to a different cultivar; use the variety label and firmness to judge it.
Once cut, pale flesh with some small seeds is normal. Large dark seeds, extensive brown spongy areas and an unpleasant smell make the fruit less attractive for cooking.
How to store an aubergine
Aubergines are more cold-sensitive than many people expect. Commercial postharvest advice cautions about chilling injury at low temperatures, especially with prolonged storage. At home a cool, appropriate environment and prompt use are sensible.
Avoid letting the fruit sit for days on a hot windowsill. If you refrigerate it, keep storage relatively brief and protect it from excess moisture and bruising.
Do not wash until you are about to prepare it. After cutting, use it promptly or keep it covered and chilled. Exposed aubergine flesh browns through oxidation; some colour change alone is not spoilage.
Preparing it for roasting or frying
Wash the skin under running water, then dry. Trim the stalk carefully with a knife and cut to the recipe's required thickness. The skin of common aubergines is edible and often helps slices hold together.
For roasting, spread pieces on a tray with some space between them. Crowding encourages steaming rather than caramelisation. For frying, remember that the porous flesh absorbs oil readily; start with a controlled amount and add only if needed.
Cook until the flesh is properly tender. An aubergine that looks brown on the outside but is firm and sponge-like inside needs more time.
Make the right choice for the meal
For layered baked dishes, a large firm globe aubergine provides wide slices. For stir-fries, slender varieties cook quickly. For baba ganoush, choose sound full fruit that can roast until completely soft.
You do not need the biggest aubergine in the shop. The one with glossy intact skin, good firmness and a healthy stalk is a better bet than an impressive oversized one with wrinkles.