Can You Compost Eggshells?
Yes. Eggshells add calcium and break down slowly but reliably, much faster when crushed. Let them dry or give them a quick rinse so leftover egg doesn't attract animals.
At a glance
| Home compost pile | Yes |
|---|---|
| Green or brown | Neither (not a green or brown input) |
| Moisture | Dry |
| Prep | Chop into small pieces |
| Worm bin | Yes |
| Bokashi | Yes |
How to compost eggshells
Let shells dry on the counter or rinse them, then crush them by hand or in a bag with a rolling pin. The finer the pieces, the faster they disappear. They're a small addition, so there's no need to add extra browns to balance them.
Grind dried shells to a powder in an old coffee grinder if you want them gone within one season.
What goes wrong
Whole shells can show up in finished compost months later. That's harmless: crush them smaller next time, or just dig the fragments into the garden. Shells with raw egg still inside can smell and draw animals in an open pile.
Worm bins and bokashi
Worm bin: Worms benefit from finely crushed eggshells, which add grit and help buffer acidity in the bin.
Bokashi: Eggshells can go into bokashi, though they come out mostly intact and finish breaking down in the soil or pile.
Balancing the rest of your pile? Check the balance with the compost mix calculator.
From hopcompost.com/can-you-compost/eggshells/ · General guidance, not professional advice.
Frequently asked questions
Do eggshells need to be crushed before composting?
Not strictly, but crushed shells break down much faster. Whole halves can last many months in a cool pile.
Should you wash eggshells before composting?
Rinsing isn't essential in a closed bin, but it helps in open piles where raw egg residue could attract pests. Letting them dry out works too.
Can you compost eggshells from boiled eggs?
Yes. Cooked or raw, shells compost the same way. Whole eggs are a different story and need more care.