Macaron Troubleshooting: Hollow, Cracked, No Feet

French macarons fail in specific, readable ways. A shell that rose and then left a gap under the dome, a top that split open, a smooth round with no ruffled foot at all: each points to a different stage of the process. That makes macarons frustrating, but it also means you can diagnose a bad tray and change one variable at a time.

The four stages that matter are the meringue, the macaronage (folding the almond flour mixture into the meringue), the resting time before baking, and the oven. This guide is organized by symptom. Keep notes on oven temperature, rack position and how long you folded, because macarons respond to small differences that are hard to remember from one batch to the next.

Hollow shells

A hollow forms when the shell rises quickly, the top sets in place, and the interior then sinks or never fills the space. The most common culprit is an oven running hotter than its setting. At around 150°C (300°F), most home ovens bake shells in 14 to 18 minutes; at a true 165°C (330°F) they puff too fast and the insides collapse away from the crust.

Underbaking produces a similar gap because the soft interior shrinks as it cools. A shell should release cleanly from the mat or parchment once cool; if it sticks and tears, bake the next tray a few minutes longer. An overbeaten meringue, dry and clumpy rather than glossy, also builds a weak interior that pulls away.

• Check the real temperature with an oven thermometer
• Bake a little longer at a slightly lower temperature
• Whip meringue to firm, glossy peaks, not dry and grainy

Cracked tops

Cracks happen when steam and air push up through a surface that cannot stretch. Large air bubbles left in the piped shells are one source, so rap the tray firmly on the counter several times after piping and pop any surface bubbles with a toothpick.

For the French method, rest the piped shells until the surface feels dry to a light touch, typically 20 to 60 minutes depending on humidity. That skin channels the rise downward into the foot. Strong bottom heat can also crack shells; doubling up baking sheets or moving the rack higher gives gentler heat.

No feet or tiny feet

Feet form when the shell's top has set and steam escapes out the bottom edge, lifting it. Batter that is overmixed is too loose to hold that structure, so it spreads flat and bakes without feet. Properly folded batter flows off the spatula in a thick ribbon and the peaks on piped shells sink back in about 20 to 30 seconds.

Missing skin and a cool oven are the other common reasons. If the oven is too low, the shells dry out slowly instead of springing up. Very humid days also make it hard for a skin to form; a fan in the room or an Italian meringue batter can help.

Lopsided feet, spreading and peaks

Feet that flare out on one side mean uneven heat. Rotate the tray halfway through, avoid placing it close to a convection fan, or bake on the middle rack with an empty sheet above to shield the tops. Shells that spread into ovals were overmixed or piped from an angle; hold the bag straight up and pipe from directly above.

Pointed tips that will not settle mean the batter was undermixed. Give it a few more folds next time. A slightly bumpy top usually traces back to almond flour that was too coarse; process it briefly with the powdered sugar and sift, discarding the large bits.

• Lopsided: uneven heat or convection fan
• Spread flat: overmixed batter
• Peaks that stay: undermixed batter
• Rough tops: coarse or oily almond flour

A reliable test routine

Weigh every ingredient. Most recipes use equal weights of almond flour and powdered sugar, with egg whites at roughly 75 to 80 percent of the almond flour weight. Small changes to that balance alter how the batter flows.

Pipe six test shells on a small sheet and bake them before committing the rest. Cut one in half once it is cool. If it is hollow, adjust the temperature or time; if it has no feet, check your folding on the next batch. Filled macarons improve after a day in the fridge as the filling softens the shells slightly.

Common questions

Do I need aged egg whites for macarons?

No. Separating whites a day ahead and letting them come to room temperature can make the meringue whip slightly more easily, but fresh whites at room temperature work well. Accurate weighing matters much more.

Is the Italian method more reliable?

Many bakers find Italian meringue shells more forgiving because the cooked-syrup meringue is very stable and less sensitive to humidity. They take a little more equipment and attention to the sugar syrup temperature.

Why do my shells stick to the mat?

They are underbaked. Bake a few minutes longer, and let them cool fully on the sheet before lifting them. Shells baked on parchment can also be released by a quick spritz of water under the paper.