Why Are My Macarons Hollow, Cracked, or Uneven?

Hollow shells

A hollow is a shell that set before the interior structure could rise into it. Two things create that: a meringue that cannot hold its air long enough, and heat that is too aggressive early on.

• Whip the meringue to firm, glossy peaks — French meringue is the least stable, Italian the most. If hollows are chronic, switch to Italian.
• Do not under-mix at macaronage; under-mixed batter traps large air pockets that collapse.
• Drop the oven 10-15°C / 20-25°F and extend the bake by 2-4 minutes.
• Avoid convection blast at the start; a gentler, longer bake sets shell and interior together.
• Age or use powdered egg white to strengthen the whites.

Cracked tops

• Rest the piped shells until a dry skin forms — 20-40 minutes depending on humidity.
• Rap the trays firmly on the bench 3-4 times to release large air bubbles, then pop visible ones with a toothpick.
• Sift almond flour and icing sugar together; coarse particles tear the surface as it rises.
• Lower the oven temperature — cracks are often too-fast expansion.
• In a humid kitchen, run a fan in the room (not in the oven) to help the skin form.

No feet, or feet that spread outward

• Over-mixed batter (too runny) spreads instead of lifting: stop macaronage when the batter falls in a slow, thick ribbon that settles in about 10-15 seconds.
• Oven too cool: feet form from steam escaping sideways under a set top, which needs enough heat.
• Too much liquid colouring — use powder or gel, never water-based liquid.
• Greasy bowl or trace of yolk in the whites kills the meringue.

Lopsided, uneven or browning shells

• Pipe at 90° to the tray, straight down, and use a printed template underneath.
• Uneven oven airflow tilts shells: rotate the tray halfway and avoid the fan's direct path.
• Browning means the top element or the temperature is too high; use a double tray or lower the rack.
• Bake one tray at a time until your oven behaviour is known.

Getting the filling right

Filling choice changes the finished macaron as much as the shell. Fat-based fillings — nut creams, chocolate spreads, coating-based ganache — keep the shell crisp for longer because they add little free water. Fruit fillings taste brighter but soften shells faster, so fill those closer to service.

Whatever you use, mature filled macarons in the fridge for 12-24 hours in a sealed container. The shell absorbs a little moisture from the filling and the texture becomes chewy rather than brittle — that maturation step is not optional in professional kitchens.