Composting eggshells with worms
Crushed eggshells are an excellent and very useful addition to your Bonter vermicomposter. They play a crucial role in buffering the pH of your compost and serve as ‘grit’ for your worms’ digestion. A simple action with great benefits for a healthy and productive compost bin.
Can eggshells go in your worm bin?
Yes, absolutely! Crushed eggshells are very suitable and highly recommended for vermicomposting. They consist mainly of calcium carbonate, which is an excellent pH buffer. This helps prevent your compost from becoming too acidic, which can happen with a lot of fruit or vegetable waste. A stable pH is essential for the well-being of your worms. In addition, the small, sharp particles serve as ‘grit’ in the worms’ gizzard, helping them grind their food. Without grit, worms cannot digest their food as efficiently. Eggshells break down very slowly, but their benefits last for a long time.
How many eggshells can you add?
Crushed eggshells can be added regularly to your Bonter. There is no strict ‘too much’ quantity that is directly harmful, as they release slowly and primarily have a structural and buffering role. Add a handful of crushed shells each time you add new food waste, or spread them throughout the bin. The most important thing is that they are well crushed (see tips) to utilize their functions optimally. They contribute to structure, mineral balance, and pH stability.
What to do instead? Alternatives & waste management
Crushed eggshells are so useful and beneficial for the Bonter that you should ideally save them for that purpose! They are essential for a healthy pH and worm digestion. If for some reason you have an exceptionally large amount of eggshells, they can also be added to a traditional compost heap (also crushed here for faster breakdown) or used directly in the garden as a calcium source for the soil (also helps against slugs). Rinse eggshells before drying and crushing them to minimize odours.
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Tips for composting eggshells
The most important tip: thoroughly crush the eggshells before adding them. This can be done by grinding them (e.g., in a clean coffee grinder or glass blender), crushing them finely with a rolling pin, or breaking/crushing them very finely by hand after drying. The finer they are, the easier they are absorbed by the worms and the better the calcium is released. Rinse the shells briefly and let them dry completely before crushing them to prevent odours. Mix the crushed shells well with the food waste and existing bedding in your Bonter. Add small amounts regularly for continuous pH buffering and grit.
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Frequently asked questions about composting eggshells
Can eggshells go in the worm bin?
Yes, crushed eggshells are very suitable and useful as a pH buffer and grit source.
Should I crush eggshells?
Why are eggshells good for pH?
Do eggshells serve as grit for the worms?
Can eggshells that still have some egg white in them go in the bin?
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