January 2024

Turning eggshells into liquid fertilizer is a simple and environmentally friendly way to utilize kitchen waste and provide plants with calcium and other essential nutrients.

In this video, I experiment with what ratio of eggshell to vinegar produces the best calcium fertilizer based on pH. I also ran the experiment for different lengths of time, from 10 minutes to 24 hours to see if time made a difference. Here's a basic guide on how to create liquid fertilizer from eggshells:

Materials Needed:
1. Eggshells: Collect clean eggshells from your kitchen, in this experiment I used 10 eggshells. Rinse them thoroughly to remove any remaining egg residue, then bake in an oven (300 degF) until completely dry, but before they turn brown. After they cool, grind them into a find powder.
2. Container: Choose a container to store the liquid fertilizer. A glass jar or plastic bottle with a tight-fitting lid works well. Make sure the container is at least 3 times larger than the amount of vinegar you use as the mixture will foam up like a soda.
3. Vinegar: You'll need an acid to help extract the nutrients from the eggshells. I used 500mL of white vinegar, but you can use some kind of citrus juice (such as lemon or orange juice).

Steps to Make Eggshell Fertilizer:
1. Add your chosen acid and eggshells to the container: The acid helps dissolve the calcium and other minerals from the eggshells.
2. Let it Sit: Seal the container with the lid, leaving enough room for the container to breathe. During this time, the acid will break down the eggshells and extract the nutrients.
3. Strain the Solution: After the soaking period, strain the liquid to separate it from the solid eggshell pieces. You can use a fine mesh strainer, cheesecloth, or coffee filter to remove the solids.
4. Dilute if Necessary: Depending on the concentration of the solution and the sensitivity of your plants, you may want to dilute the liquid fertilizer with water before using it. A general guideline is to dilute it with water so that you get about 1 eggshell for each plant.
5. Apply to Plants: Use the liquid fertilizer to water your plants. Apply it to the soil around the base of the plants, taking care not to splash it on the foliage.

In summary, I found that 2 eggshells for every 100mL of vinegar to be the best ratio for making eggshell fertilizer.

Some Additional Tips:
- Storage: Store any leftover liquid fertilizer in a sealed container in a cool, dark place. It can be stored for several weeks to a few months, but it's best to use it as soon as possible for maximum freshness and efficacy.
- Application Frequency: You can use eggshell liquid fertilizer as part of your regular watering routine, applying it every few weeks during the growing season.
- Nutrient Boost: Eggshell fertilizer provides plants with calcium, as well as other minerals like magnesium and potassium. It can help improve soil structure and promote healthy plant growth.

By recycling eggshells into liquid fertilizer, you not only reduce waste but also provide your plants with a natural and nutrient-rich source of nourishment.