Eggshells are a great addition to the garden. Making calcium powder from eggshells is a very simple process. When making calcium powder from eggshells you want it to be as fine as possible. This allows a greater surface area for the microbes to work. Breaking down that calcium powder into a form that is available for your plants.
Table of Contents
Materials to make calcium powder from eggshells
To make calcium powder from eggshells you will need the following:
- Eggshells
- An oven (a regular oven or a toaster oven)
- A grinder
- A fine strtrainer
- Containers for sifting and storage
Toaster Oven | Coffee Grinder | Strainer | Storage containers |
---|---|---|---|
Steps to make Calcium Powder from eggshells
- Rinse the inside of the eggshells
- Bake
- Crush the eggshells
- Grind
- Sift
- Store
Rinse
Before baking it is recommended that you remove the clear liquid (known as the albumen from within the shell). It isn’t necessary but I do find the final result to be more of a courser powder when it is removed.
Bake
Baking the eggshells ensures you kill off disease-causing bacteria like salmonella. Spread the eggshells out on a baking sheet. you don’t want the eggshells to be piled too high on top of each other. The air should be able to flow through relatively easily. Put the tray in the oven and bake at 300 F for about 30 min. The trick here is you want the eggshells to be dry and brittle. When it’s finished the eggshell should snap completely rather than just break.


Crush
You can crush the eggshells by hand, using a rolling pin or wrapping them in a kitchen towel and crushing them that way. The point here is just to get them into small pieces for the next phase.
Grind
To grind the eggshells you can use a mortar and pestle, a coffee grinder or a spice grinder. Put the eggshells in your desired grinding apparatus and grind the eggshells down to a powder.
Sift
Use an appropriate size strainer to sift the calcium powder from any large particles. Return whatever didn’t go through the strainer to the grinder to be processed again.


Store
Store the calcium powder in an airtight container.
Final Thoughts
Eggshells are almost 100% calcium. Calcium is important for building the cell structure of plants. It is also a natural buffer in soil and helps regulate soil pH. Calcium is particularly important for plants like tomatoes and eggplants. Without enough available calcium, these plants are susceptible to blossom end rot and reduced shelf life. So, the next time you are planting your tomatoes you can add a handful of your homemade calcium powder before transplanting to ensure you long-lasting produce when it is time to harvest.
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