How do you fix hollow French macarons?
Hollow macarons can be fixed by whipping the meringue to the correct stiffness, folding the batter to the ideal consistency during the macaronage stage, rapping the tray after piping, using the correct tools, baking at the optimal temperature and possibly the addition of a "secret" ingredient.
Batter is too wet: A batter that is too wet will cause flat macarons with little to no feet. A wet batter can be from macarons that have too many egg whites or egg whites that have too much water. Egg whites are made up mostly of water. In fact, 90% of the egg white is water while only 10% is protein.
Macarons can become lopsided from improper piping techniques, use of an overly strong fan to dry the macarons, oven's convection fan is too strong, use of a warped baking pan, shells were rested for too long, baking temperature too high or improper macaronage techniques.
There can be a lot of reasons why macarons are hollow – it can be wrong macaronage, wrong oven temperature, too humid weather, overmixing or undermixing the batter and the list goes on and on.
Remember that it's always better to underbeat than the contrary: as you transfer the batter to the piping bag, and then pipe the shells onto the baking sheets, the batter will continue to thin. If you overbeat from the getgo, you'll end up with cracked or feetless macarons.
When macaron batter is over-mixed, there's not much air bubbles left to give the shells lift during baking. Therefore, they come out flat without feet. Also, if macarons weren't rested to form a skin before baking, it could cause no feet macarons.
Resting too long may may be the cause of lopsided macarons, because if the shells rest for too long before baking the protein structures begin to deflate, causing the shells to bake unevenly. Uneven heat is the biggest culprit for lopsided macarons.
Generally, most macaron bakers set their home conventional ovens between the temperatures of 290°F (143°C) - 325°F (163°C). If you're using a convection oven, reduce these temperatures by 25°F. How long should I bake macarons?
Depending on your sweet-o-meter or taste preference, add some more confectioners' sugar or even cornstarch to a buttercream mixture to stiffen it up. My preference is always cornstarch because it adds thickness without adding sweetness.
If your macarons have cracked or broken, you can try to put them back in the oven. Preheat the oven to 350 degrees Fahrenheit and place the macarons on a baking sheet lined with parchment paper. Bake for 5-8 minutes, or until the shells are crispy. Let the macarons cool completely before serving.
Why are my macarons raw inside?
Not baking the macarons long enough may cause them to be too gooey on the inside and not have the top be attached to the bottom. This is an easy fix, bake the macarons until they are fully baked. To know when the macarons are done baking, wiggle one shell and if it jiggles continue to bake it.
"Resting" a macaron shell involves letting it air dry for 30 minutes after piping until the surface loses its glossy sheen and you can lightly touch the shell without any trace of the batter transferring to your fingers.
