Why does my cheesecake crack?

A cheesecake is essentially a baked custard, and it cracks for the reasons custards crack: too much heat, too much air beaten in, or too fast a temperature change. All three are avoidable and none ruins the taste.

Step by step

1. Beat as little as possible.Beating incorporates air, which expands in the oven and collapses on cooling, taking the surface with it. Mix on low just until combined, and scrape the bowl rather than beating longer.
2. Use room temperature ingredients.Cold cream cheese needs far more beating to smooth out, which is exactly the thing to avoid. Take everything out an hour ahead.
3. Bake low and slow.Around 150-160°C. A hot oven sets the edges long before the centre and the difference in shrinkage is what tears it.
4. Use a water bath, or a tray of water below.It moderates the heat and adds humidity. A full water bath needs the tin wrapping in foil; a tray of water on the shelf beneath is nearly as effective and much less trouble.
5. Take it out while the centre still wobbles.The middle should move like set jelly when nudged — a circle about the size of a coaster. It continues cooking as it cools. Baking until firm is the most common cause.
6. Cool it slowly in the oven.Turn the oven off, prop the door open, and leave it for an hour. A sudden move to a cold kitchen shrinks the surface faster than the middle.
7. Run a knife round the edge while warm.It releases the sides so the cheesecake can shrink inwards without pulling itself apart as it cools.
8. Chill for several hours, ideally overnight.It sets properly and slices cleanly. A cheesecake cut warm will not hold its shape whatever else you did.

Tips

• A crack changes nothing about the taste. Sour cream, fruit or a dusting of cocoa covers it completely, and that is what most bakeries do.
• Do not open the oven during baking. The temperature drop is a common trigger.
• If the top browns before the centre is set, the oven is too hot. Lower it and cover loosely with foil.

Questions people ask