4 Ways to Use Up Onion Skins

When I wrote about my week of closed-loop cooking for Food52, my attempt was fruitful (and fun). Still, I had a hard time finding a good use for all my leftover onion skins. Lucky for me, many of my friends—both within and outside of the Food52 community— reached out to share their best tips for making the most of them. Below, a roundup of my favorite ideas. You might very well find yourself buying onions just for the skins!

1. Onion skin stock
2. Onion skin snack (fried onion rings with an onion skin batter)
3. Onion skin dye
4. Compost

1. Onion Skin Stock

The simplest way to integrate onion skins into your cooking is by stirring these nutritional powerhouses into your vegetable stock. After making my own stock, I am totally convinced that store-bought broths just don’t cut it.

This recipe for root-to-stem cooking is especially easy and delicious. All you need to do (really and truly) is boil a bunch of onions skins and carrot tops and whatever else you have on hand to create the core for nourishing soups. As we steer into spring, onions’ immunity-boosting properties are invaluable, and an onion skin stock is a good way to get all that good stuff. If you’re worried about bitterness, use fewer onion skins. In my experience, an onion skin-rich stock works wonders, but if you’re a super-taster (as my mother is) it’s better to play it safe

2. Onion Skin Snack

I used Nik from A Brown Table’s recipe for cauliflower Parmesan pakoras to experiment with onion skins. I finely minced several onion skins with a little garlic—you can even use the softened ones leftover from making stock—then folded the mixture into his pakora batter. It's a sneaky way to enjoy the antioxidant-rich properties of onion skins.

Then, I used the same technique to whip up a batch of pakora-fried onion rings—a delicious topping to crumble onto soup and in salads or to eat as a snack on its own. I peeled the onions, saving their thick outer shells (but discarding the paper), then cut the insides into 1/4-inch-thick rings. Then, I cut the onions into 1/4-inch-thick slices, boiled the skins until pliable (I didn’t use quite as many skins as there were onions—and this step is optional), and blended the soft skins with some olive oil and salt until smooth.

I then used incorporated the onion skin mush into a pakora batter and used it to coat the onion rings, which I then fried like pakoras. I served them with a bowl of tangy yogurt sauce made from kefir, olive oil, lemon juice, and lots of chopped cucumbers, but I like this dill sauce and tahini sauce as well.

3. Onion Skin Dye

One of my favorite uses for onion skins comes courtesy of my friend Adriana Moreno of the Portland-based Moonshadow Goods. Adriana's handmade quilts and naturally-dyed linens are dynamic proof that we can work with what we have leftover to create something beautiful and fresh.

Adriana’s recipe, originally published in Loam and later in Chickpea, is the perfect opportunity to strike up a conversation with your local farmer (because you’re going to need a lot of onions skin) and feed your DIY spirit. Have fun with it!

What You'll Need

• Plenty of onion skins: the more the better! (every trip to the local market is an opportunity to gather some onion skins—be prepared to get some weird looks and questions on what you’ll be doing with them)
• Natural fabric or fibers (like cotton, silk, wool, felt, wool yarn)
• Large pot: stainless steel is preferred, and I would recommend a pot that you don’t use for cooking food
• Strainer
• Heat source (i.e., stove, hot plate, propane stove)
• Wooden spoon
• Bucket for rinsing
• Gloves, optional

How to Do It

1. Fill your pot with the onion skins, then add enough water to submerge them. Leave some room for your fabric.
2. Boil the skins uncovered for 1 hour. Stir a few times throughout the hour.
3. I like to let the onion skins soak/steep overnight. This step is not necessary but allows for a more concentrated dye bath.
4. Optional step: Make fun patterns by folding, wrapping and tying fabrics in different ways.
5. Next, soak your natural fabric in clean warm water for at least 45 minutes. (I like to soak my fibers for about 2 hours.) Soaking your fabric will allow the fibers to open up and dye evenly.
6. Strain out the onion skins from the bath.
7. Add your pre-wet fabric to the bath. With the fabric in the bath, bring it back to a boil for 1 hour. Keep an eye on the bath and make sure to release any air bubbles from within the fabric.
8. Once again, let the fabric soak/steep in the dye bath overnight. Letting the fabric soak in the dye bath overnight will yield more saturated colors.
9. The next day, remove your fabric from the dye bath and rinse with cold water until the water runs clean. Three to four rinses should do.
10. Your used onion skins can be put into a compost or mixed into soil. I’ll also use the dye bath and rinsing water to feed outdoor plants, ensuring nothing goes to waste.
11. Then hang your newly dyed fabric to dry and voilà!

4. Onion Skin Compost

You won’t always find a use for an onion skin—but that’s very alright because a happy, hearty compost mix loves a good onion skin.

If you are growing a garden, no matter how small (even the herbs on your sill like a compost-rich soil) making compost is a true adventure in working with what you have. Christopher Shein’s A Vegetable Gardener’s Guide to Permaculture is one of my favorite resources for learning how to cultivate an edible ecosystem.

For those of you new to this small miracle, compost is a nutrient-rich matter that’s used to fortify soil. I’d go to Shein for a more thorough explanation of how to whip up compost in your backyard or apartment bedroom; that said, getting started on creating your own compost doesn’t take much more than some vegetable scraps, a bucket, and a willingness to get a little dirty. You’ll need a mixture of wet and dry materials—as well as a little water and air—to build a nourishing compost mix. So save your onion skin scraps (and newspaper clippings, and fish bones, too) because these are essential to creating healthy soil.

Ready to dive in? This handy guide breaks it all down.

Ready to get cooking?

Do you have a favorite way to use onion skin scraps? Tell us in the comments below!