Like many families, we eat eggs and this produces egg shells. While I am aware that composting is a possibility I am wondering if there are other things we can do with them. We are not raising chickens of our own yet so feeding them back to chickens is not a possibility. We do however have turtles and carp (both ornamental and edible).

1) Can egg shells be fed to turtles and other animals as a calcium supplement (in lieu of cuttlebone)? If so, any advice on how to do this?

2) Is there any reasonable way to incorporate eggshells into cooking to produce extra calcium for human consumption?

3) are there other household uses for eggshells?

5 Answers 5


I've heard conflicting reports on feeding eggshells to reptiles. Most people seem to think it's ok. The concern seems to be about heavy metals and hormones in the shells--though if you're buying organic I don't think that would be as much of a problem--and salmonella contamination. Tortoise Trust says not to do it because of the salmonella risk and because they claim that "Eggshells are not a good source of calcium, in fact." I have to say that such a claim runs counter to everything else I've ever heard about egg shells... unless maybe they meant that the calcium in raw eggshells is somehow difficult for a turtle's digestive system to absorb? (Disclaimer: I am no turtle expert.)

As far as human consumption... I've heard that some Thai food has eggshell as an ingredient, though I haven't come across any recipes. This woman made eggshell cupcakes. I don't think you're supposed to eat the shell in that case, but the baking would kill any salmonella and then you could grind them up for other uses. Then again there might be bits of cake stuck to them. Haven't tried it myself, yet. An alternative would be just to pop them in the oven while you're baking something else. From a sustainability standpoint I can't justify heating up the whole oven just for eggshells...

Some folks also claim you can use egg membrane as a bandage, or to treat pimples.

This site suggests a ton of other uses, including Christmas ornaments, homemade sidewalk chalk, and as an abrasive cleaner for dirty pans.

  • 1
    I bet shells from hard-boiled eggs would not have the bacteria issue.
    – theUg
    Commented Mar 20, 2013 at 22:29
  • +1 for "...I can't justify heating up the whole oven just for eggshells...".
    – Nate
    Commented Aug 7, 2013 at 5:10

Egg shells can be used as a calcium suppliment for humans. The most common way is to grind them. They can be baked first (to make the more brittle, and to kill any pathogens). Or this source suggests boiling them first, then simply letting them dry.

You can grind them in a coffee grinder, or with a mortar and pestle, then mix the powder with other foods. In small quantities, it should mix well with hot cereal, soup, stir-fry, etc.

I'm sure you could use the same process to prepare egg shells as a calcium supplement for pets or other animals as well, then mix it with their food and/or water.


You can also use them in the garden. I dump them in an open gallon jar to dry. Every now and then I crush them down. Grind them coarsely, and use them as slug barriers, or just mix into the garden soil.


I've always washed them out and let them soak in the water I use for houseplants to leach minerals into. I've always heard it was good for plants, but have no evidence whatsoever to back it up. Seems to work though.

  • 1
    Hello there, and welcome. Thanks for your answer. Would you like to elaborate a little more? A fuller answer will help all our interested readers.
    – 410 gone
    Commented Mar 27, 2013 at 9:53

One answer I did not see here, that I often do, is to use it as a fining agent to clarify your homemade (white) wine.

You first sterilize them by putting in the oven (preferably while using it for other things) so it kills any nasty's removes any remaining moisture.

Crush them until they are fine dust (very small pieces are OK)

Then add them to your wine if it wont clear on it's own. (this is for about 1 month before bottling your wine.

The science behind this is that the shells will move up and down in the wine grabbing on to small particle that are preventing it from clearing. After a month, the shells will stay at the bottom and your wine is clear.

I know the OP probably doesn't make wine but this might help others with the same question.

Originally got the idea from this site many years ago: Finishing Your Wine

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