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How to Make Egg Shell Powder
The humble egg shell can be a huge boost to your garden and to your chicken flock. But tossing the whole shells directly into the compost can take forever to break down.
Cue homemade egg shell powder.
In the garden, egg shell powder is a good soil amendment. It adds extra calcium and other minerals back into the soil. And since most soils are woefully depleted- this is not just about better yields, it’s also about better care for the land.
Tomatoes especially love egg shell powder- apparently it’s the key to avoiding blossom end rot. Other veggies that contain a lot of calcium will also need a lot of calcium to grow- think of chard and spinach.
As cool as boosting soil nutrients is, egg shell powder has even more uses than that.
Sprinkling egg shell powder on the surface of your garden beds can be effective at stopping pests, like slugs.
Outside of the garden, a coarser egg shell powder can be a good calcium supplement to your laying hens- plus it can serve as a source of grit (essential for chicken digestions).
I can’t speak from personal experience, but you can use powdered egg shells as a calcium supplement yourself: or even make a DIY toothpaste from egg shell powder. (You can read a recipe for that here. Or deep dive in an actual scientific study, published in the National Library of Medicine in 2021, here)
Personally, I’ve been making egg shell powder just for use in the garden. But I’m thinking that I need to up my egg shell game and try out that homemade toothpaste. Regardless of what you’ll use it for, the process of how to make egg shell powder is the same.
How to Make Egg Shell Powder
Making egg shell powder starts with an extraordinarily easy step: eating a bunch of eggs.
We’re only a family of 3, but we’re easily going through over 2 dozen eggs a week. And since have plenty of chickens to keep us supplied with eggs year-round, we’re also getting huge supply of egg shells.
You can process as few or as many shells at once as you want, but I like to wait until I have a few dozen stored up. We just keep a small container on the counter and add the shells to it every day. Once it’s full, it’s time to process the shells into powder.
Next, we need to dry out the egg shells. In the winter time, I use a cast iron pan and our oven. Simply arrange the shells in the pan, and roast at 200* – 300* until the shells are dry and brittle. Stirring occasionally as they roast will speed the process along.
In the summer time- when I don’t want to heat the house up with the oven- I’ll use my dehydrator. Arrange the shells on the racks, and leave the dehydrator to do its thing. I’ll usually start it in the evenings, let it run overnight, and finish making egg shell powder the next morning.
Once the shells are cooled, it’s time to grind.
I’ve seen many tutorials advising you to use a food processor or an electric coffee grinder to powder egg shells. I use a manual coffee grinder, which I ordered specifically for powdering egg shells.
(This is the one I use right now, but after using it on dehydrated liver it’s gotten rather dull. I’m looking to upgrade to a better one in the near future.)
To get a coarse grind, I run the shells through once. For a finer grind, twice.
For use in the garden, a coarse grind works- but a finer grind will allow the shells to break down and become available to the plants faster. For the chickens, I like a coarser grind because they need grit anyway, and shells can help with that. If you’ll be making toothpaste or taking this egg shell powder yourself- I’d go for an extra fine, powdery grind.
Storing egg shell powder is easy- I pour it from the grinder into a mason jar, add a lid, and call it a day.
Now that you know how to make egg shell powder, you can see that there’s no need to have your egg shells go to waste. Just a little bit of work can yield a mineral-rich boost for your garden, your birds, and yourself. I hope this post has given you some inspiration for another no-waste kitchen project that you can tackle, even on an urban homestead. Read my full list of ideas on how to use up your egg shells here!
Thanks for reading and happy homesteading!
-Maia
PS If you haven’t added chickens to your homestead yet, check out my post on 10 reasons why you should- besides egg shells of course. If you’re new to gardening this year, I also have a post all about seed starting indoors- here. Limited on space but still want to get into urban homesteading (and urban egg shell production)? Coturnix quail may be the perfect fit for you. Find out the simple way I’m keeping quail on our homestead in this post.
