If you eat eggs, make sure you make the best use of those shells! Most of an eggshell is calcium. In fact, about 95% of shells are calcium carbonate…the same stuff that sea shells, coral, and limestone are made from (the other 5% includes proteins, calcium phosphate, and magnesium carbonate). Here’s a list of what you can do with those shells so the calcium and its brittle shell don’t go to waste.
USE EGGSHELLS FOR THIS
1) Give your hens a calcium boost. Eggshells contain 95% calcium, and hens need calcium to lay eggs that have those strong shells. There is nothing unhealthy about feeding your hens eggshells, as long as those shells have been sterilized to kill bacteria (see below on how to do this) and offered in ground form. Pay special attention to shell sterilization if you get some of your eggs from another source where you can’t be sure of the laying hen’s health.
2) Give your pets a calcium boost: In the case of eggshells, what is good for chickens is good for your pet. Adding pulverized eggshells to their food provides extra calcium for bone health. And just like using shells for chickens, be sure to sterilize the shells first.
3) Give yourself a calcium boost: Consuming calcium from eggshells can help you, too. In a 2003 study published in the International Journal of Clinical Pharmacology Research, eggshell consumption helped stop bone loss in postmenopausal women. While you can consume pulverized eggshells for added calcium, remember that calcium amounts very greatly in shells, so there is no way to tell exactly how much calcium you are getting (but we know you are getting more than if you didn’t consume the shells at all). Be sure you bake the shells before consuming to prevent ingesting any bacteria if you haven’t washed the shell before eating the egg (see below).
4) Incorporate them into your soil: It’s a great practice to add ground eggshells into your garden soil (and your indoor pots, too). But realize that it takes awhile for those shells to break down enough for the calcium to be available to your plants. In fact, eggshells can take many years to decompose fully and it will take several years to see the benefits of those eggshell additions to soil. But don’t let this deter you as adding eggshells to soil is great for plants! Start now…in a year or two you’ll start to see benefits (the finer you grind the shells, the more quickly you’ll see benefits). And don’t forget to sterilize those shells before adding them to the soil to prevent adding bacteria to your garden.
5) Keep garden critters at bay: Slugs are slippery little devils, and they dislike the chalky sharpness of ground eggshells. Cutworms don’t like it, either. Sprinkle the eggshell around plants like tomatoes, peppers, broccoli, and cabbage to keep their stems safe and destructive critters away. Make sure you cover the surface of the soil around the entire stem.
6) Clean your pots and pans: Yes, you can grind your eggshells into a powder and use it as an abrasive. But, it being an abrasive and all, it will scratch! I’ve used this for especially stubborn spots on cast iron pans or stainless steel (on the insides). Don’t use this on any surface that you want to see a scratch on.
7) Make your coffee sweeter: Adding crushed eggshells to your coffee grounds helps to lessen the acidity of your coffee. Then you can toss the used grounds and eggshells in your compost bin. Better yet, toss them both into your garden soil! The eggshells have the calcium, but the coffee grounds provide the nitrogen.
PREPARE EGGSHELLS LIKE THIS
For most eggshell uses, it is better to make sure they are clean and free from bacteria. If you don’t wash the eggs thoroughly before using, bake the shells at 150 degrees Fahrenheit on a cookie sheet for about 10 minutes.
You can grind your eggshells either wet or dry. I personally find grinding them dry to be easier, but decide which method works best for you in your kitchen:
To grind eggshells wet, simply take all of your eggshells, place them in a blender and fill the blender with water to about 1/2 way up the eggshells. Then whizzzzzzzzz, and drain. What to do next is where I find the difficulty. Small bits of wet shell are not necessarily cooperative, and most uses for eggshell are easier to implement when the shells are dry.
To grind eggshells dry, you can either leave them sit in a bowl until they are thoroughly dry (I keep the pretty bowl shown above next to my sink and simply stack eggshells as they accumulate), or you can bake them. Baking to dry and sterilize them can serve double duty here! If 10 minutes baking at 150F doesn’t dry all of the wet egg remnants inside the shell perfectly, just leave them bake in the oven until the insides of the egg are perfectly dry. (To see a video on how to use your blender and a mason jar to grind your eggshells and other foods, click here.)
DON’T USE EGGSHELLS FOR THIS
I just can’t recommend that you use eggshells to start seedlings, even though this is a popular infographic on Facebook and all over the interwebs as an eggshell tip (I know…I’m the problem child sometimes). Seedlings are like icebergs…at best what you see above the soil is equal to what is going on below the soil. In fact, sometimes the root system is much larger than the seedling. Half an eggshell just doesn’t have the space necessary to support a growing and intricate root system unless you transplant it pretty quickly to the garden. In drier climates it is also difficult to keep such a small amount of soil moist enough to keep a healthy seedling happy.
Eggshells do not sharpen garbage disposal blades. I don’t think it harms the garbage disposal any more than anything else, but I have read that egg shell bits in the drain, because they are heavier than usual kitchen sink refuse, can contribute to drain clogs. The idea being they settle into a pipe at some point, and slowly start to trap debris. Even more reason to use eggshells for one of their many beneficial purposes!