Why Pastry Shrinks (and How to Stop It)

There is nothing more frustrating than pulling a beautifully lined tart tin from the oven only to find the pastry has slid down the sides, leaving you with a shrunken, uneven case. The good news is that shrinking is almost always preventable. It happens for three main reasons: the gluten in the flour contracts as it bakes, the butter melts and releases water before the structure sets, and the pastry is stretched when lining the tin. The solution is a combination of gentle handling, thorough chilling, and the right baking technique.

Start by resting your pastry in the fridge for at least 30 minutes after making it, and again after lining the tin. This relaxes the gluten and firms up the butter, so the pastry holds its shape. When you roll it out, use light, even pressure and avoid stretching it to fit. Instead, lift and press it gently into the corners of the tin. A metal tin is your best friend here: it conducts heat quickly, setting the edges before they have a chance to shrink.

Lining the Tin: The Foundation of a Perfect Case

Roll your chilled pastry to about 3mm thick, working quickly so it doesn’t warm up. To transfer it, roll it loosely around your rolling pin and unroll it over the tin. Ease it into the base and up the sides, being careful not to pull or stretch. Use a small ball of spare pastry to press it into the fluted edges – this gives a neat finish without stretching. Trim the excess by rolling your pin across the top of the tin, or use a sharp knife.

Now, prick the base all over with a fork. This is called docking, and it allows steam to escape so the pastry doesn’t bubble up. But don’t go overboard: too many holes can let filling leak through later. For a sweet tart case, you can also brush the inside with a little beaten egg white and chill for 10 minutes; this creates a seal that keeps the base crisp.

The Role of Baking Paper and Ceramic Beads

This is the step that truly stops shrinking. Line the pastry case with a large sheet of baking paper, scrunching it first so it sits comfortably in the corners. The paper should cover the base and come up over the edges. Fill the case to the very top with ceramic baking beads. These heavy little spheres weigh the pastry down and, crucially, support the sides so they stay upright as the pastry sets.

Why ceramic beads? They are heavier than rice or dried beans, conduct heat gently, and can be reused endlessly. If you don’t have beads, dried rice or beans work in a pinch, but they are lighter and may not hold the edges quite as firmly. Never use them for cooking afterwards – keep them in a jar for baking only. Fill right to the top of the tin; the beads should be level with the rim, pressing the pastry against the sides.

The Two-Stage Bake: Timing and Temperature

Preheat your oven to 200°C (180°C fan, gas 6). Place the lined tin on a baking tray and bake for 20 minutes. The pastry should be set and the edges lightly golden. Carefully lift out the baking paper and beads – do this gently, as the paper can tear. Now return the case to the oven for a further 5–10 minutes, until the base is dry, crisp, and golden all over. For a fully baked case that will hold a wet filling, bake for another 10–15 minutes, until it sounds hollow when tapped.

• For a part-baked case: bake with beads for 20 minutes, then remove beads and bake for 5 minutes. Cool before filling.
• For a fully baked case: bake with beads for 20 minutes, then without for 10–15 minutes, until deep golden.
• For a very wet filling: brush the hot case with beaten egg and return to the oven for 2 minutes to seal.

Keep an eye on the edges: if they are browning too quickly, cover them with strips of foil. Every oven is different, so use these times as a guide and trust your eyes and nose.

Troubleshooting and Finishing Touches

If your pastry still shrinks, the likely culprit is warmth. Work in a cool kitchen, chill the lined tin for 15 minutes before baking, and handle the pastry as little as possible. Overworking the dough develops gluten, which causes contraction. Also, never stretch the pastry when lining – let it relax into the tin. If you are using a loose-bottomed tin, place it on a baking tray to catch any butter that melts out.

Once baked, cool the case completely in the tin before removing. It will firm up as it cools, making it easier to handle. Store it in an airtight container for up to two days, or freeze for up to a month. Then fill with your favourite custard, fruit, ganache, or lemon curd. With these techniques, you will have crisp, golden, perfectly upright pastry cases every time – ready to show off your baking skills.