Similar, sensational headlines often tempt people to use eggshells around the house or garden. Eggshells consist of more than 90% calcium carbonate (CaCO₃), but they also contain magnesium, phosphorus and other minerals.
Boiling and processing eggshells can solve several problems at once:
No more acidic soil and poor harvests (for gardeners)
Regularly boiling eggshells (about 10-15 minutes) disinfects them and removes protein residues and pathogens (such as salmonella).
Eggshell broth as fertilizer: Don’t throw away the boiling water! It contains leached calcium. After cooling, use it to water tomatoes, peppers, cucumbers or houseplants. This prevents, for example, the blackening of tomato tips (necrosis), which is caused by a lack of calcium.
Ground eggshell flour: Boiled and dried eggshells are ground into a fine powder. This powder is excellent for neutralizing acidic soil in flower beds.
No more burnt-on food and deposits (in the kitchen)
Boiled and coarsely ground eggshells are an excellent, 100% natural and ecological cleaning agent.
Sprinkle burnt-on pots, pans or baking trays with crushed eggshells and a drop of dishwashing detergent and then clean them with a sponge – all without harsh chemicals.
Place the crushed eggshells in a narrow glass vase or carafe with a little water and dishwashing detergent and shake thoroughly. This makes it easy to remove limescale deposits, even in hard-to-reach places.
No more bitter and sour coffee
An old trick from our grandmothers says that adding a piece of clean, boiled and crushed eggshell directly to the coffee grounds before brewing neutralizes excessive acidity and bitterness. The coffee then tastes much smoother and more balanced.
No more snails and slugs (Mechanical barrier)
Coarsely crushed shells, scattered in a circle around young seedlings (e.g. lettuce or marigold plants), form a sharp barrier. The soft bodies of snails and slugs do not like to climb over the sharp edges of the shells.
💡 Last tip: Boiling the shells is an important step if you want to store them for a long time or use them as fertilizer. This removes organic waste that would otherwise cause an unpleasant odor in the container.