If you don't have eggs, here are some ideas about what you can use instead. There are garden plants that can be grown and utilized to make egg substitutes. And there are other leavening agents that can be used as well.

Aquafaba

To begin with, there's aquafaba, which means bean water. The liquid in a can of beans is usually drained and discarded. However, it can easily become an egg substitute.

Chickpeas (garbanzos), great northern, navy, and cannellini beans have a neutral-colored liquid that can be used in any recipe. Baby lima beans work well too. Black bean aquafaba can be used in recipes where the darker color and stronger taste doesn't matter, such as those requiring cocoa. Broth from pinto beans is too rich and earthy even for brownies and should not be used.

Important: Wait to season your cooked beans until after you’ve drained off the aquafaba so it doesn't acquire a strange taste.

This liquid has properties that are similar to egg whites and can be used to prepare things ranging from meringues and macarons to marshmallows. Aquafaba can be whipped into vegan mayonnaise, baked into meringues or macaroons, and shaken to make foams. Any residual bean flavor will disappear once it’s cooked, making it good for both sweet and savory recipes.

How to substitute: Use 3 tablespoons of the bean water to replace each egg. If you’re using it as a binder, whip slightly until foamy. For meringues or whipped egg white substitute, use an electric mixer to beat into peaks.

Using dried beans and peas

Here’s how to make homemade aquafaba from dried beans, water, and salt.

mass of white dry beans

Total time: 5-16 hours, depending on soaking time. Prep time: 15 minutes. Yield: 1&1/2 cups aquafaba, which is equivalent to 8 eggs, plus 5-7 cups cooked beans.

1 pound dried beans (454 grams)
5 cups water
1 teaspoon salt

Carefully sort through the dried beans, then thoroughly rinse them. Put beans in a very clean pot or slow cooker. Any trace of oil will ruin the chance of having fluffy aquafaba. Be sure to use only clean, oil-free utensils. Add water and salt, soak for 2-12 hours; cook until tender. If beans rise to the surface, add enough water to barely cover.

Slow cooker: Put the lid on the slow cooker. Cooking speeds vary, but usually beans will cook on high in about 3 hours and on low in about 8 hours.

Stove: Bring a covered pot to a boil over high heat; reduce heat to low so beans barely simmer. Cook for about 2 hours.

Instant Pot/pressure cooker: Follow the instructions that came with your model. While it may take longer for 8 quart models to come to pressure than the smaller sizes, once pressurized the cooking time should be the same.

When beans are tender, carefully pour the cooking liquid through a sieve into a container. If you have more than 1&1/2 cups of liquid, pour all the liquid into a pot and boil it uncovered on medium-high until reduced as desired. Some recipes such as macaroons call for reducing the aquafaba even further. You can do that at this point.

If your recipe calls for whipping the aquafaba, chill it first.

Unwhipped aquafaba keeps refrigerated for seven days and frozen for a year. Freeze in ice-cube trays and store in a freezer bag.

Other leavening agents you can use

baking powder, yeast and soda

Carbonated water

This can add moisture to a recipe, but it also acts as an excellent leavening agent. The carbonation traps air bubbles, making the result light and fluffy.

You can replace an egg with one-fourth cup (60 grams) of carbonated water. This substitution works well for cakes, cupcakes and quick breads.

Apples

Applesauce can be used in place of eggs in some cakes and cookies.

No Egg Applesauce Cake

1/2 cup butter or margarine, softened

1 cup sugar

2 cups all-purpose flour

2 teaspoons baking soda

1&1/2 teaspoons ground cinnamon

1/2 teaspoon ground cloves

1&1/2 cups unsweetened applesauce

1/2 cup raisins

In a bowl, cream margarine and sugar until fluffy. Combine flour, baking soda, cinnamon, and cloves. Alternate adding this and the applesauce to the creamed mixture. Beat on low until well blended. Stir in raisins.

Pour into a 9-inch non-stick baking pan. Bake at 350° for 35-40 minutes or until a toothpick inserted in the center comes out clean. Cool on wire rack.

ripe apples in a bowl

Gelatin

If you can or preserve food, you probably have unflavored gelatin on hand.

To replace one egg, dissolve 1 tablespoon (about 9 grams) of unflavored gelatin in 1 tablespoon (15 grams) of cold water. Mix in 2 tablespoons (30 grams) of boiling water until frothy. You can also use 1 tablespoon (9 grams) of agar-agar powder mixed with 1 tablespoon (15 grams) of water to replace an egg.

Neither replacement will affect the flavor but can produce a slightly stiffer texture.

**Gelatin is rich in protein and has a unique amino acid profile that gives it many potential health benefits. There is evidence gelatin may reduce joint and bone pain, increase brain function and help reduce skin aging.

Potatoes

Mashed potatoes add instant moisture to anything that calls for an egg, and can add a light, airy texture to breads and rolls.

How to substitute: 1/4 cup mashed potatoes for each egg. You can also use 2 tablespoons of re-hydrated instant mashed potatoes.

strainer of small potatoes

Water + Vegetable Oil + Baking Powder

This egg replacement combines water, oil, and baking powder to leaven baked goods like cookies and cakes. Caution: if your recipe has more than three eggs, this substitute will result in a very oily cake.

How to substitute: For each egg, combine 2 tablespoons of water with 1 tablespoon vegetable oil and 2 teaspoons baking powder.

Baking Soda and Vinegar

The carbonated reaction helps leaven baked goods like bread, resulting in a fluffy dough that rises beautifully.

How to substitute: Replace each egg with 1 teaspoon baking soda and 1 tablespoon white vinegar.

Egg Substitutes for Cakes and Cupcakes

For each whole egg used you can substitute one of the following:

½ medium banana, mashed

¼ cup (4 tablespoons) apple sauce

¼ cup (4 tablespoons) tofu

¼ cup (4 tablespoons) buttermilk

Remember the Chia Pet© craze?

To replace an egg, use 1 tablespoon of chia seeds mixed with 3 tablespoons of water and let the mixture sit for 15 to 20 minutes until it becomes a gel. You can prepare this the night before.

chia pet

How to grow your own chia

The Mexican chia (Salvia hispanica) was grown by the Aztecs and other indigenous people. It was rediscovered in the 1900s and is now grown for its nutritious seeds. Plants grow quickly, needing only four months from germination to flowering.

Start seeds indoors in March and April or outdoors in April and May after all chance of frost has passed. Germinate indoors by scattering seeds on top of a damp paper towel or over seed-starting mix. Chia seeds germinate in 3-14 days. Covering the seed tray with plastic wrap helps keep the seeds moist. Once seeds germinate, carefully move them to pots.

Chia plants require warmth and bright light. Keep seedlings where they will receive 6-8 hours of bright light daily. Water when soil is dry to the touch. In 4-6 weeks or when seedlings are at least 6 inches tall with six to eight pairs of leaves, plant them in the garden.

The University of Kentucky's new early summer lines of chia have been licensed to Heartland Chia, a producer-owned company in Franklin, Kentucky. Heartland Chia provides non-GMO seed and production advice to growers and, in turn, markets the chia they produce.

mexican chia

The plants prefer a sunny, well-drained location. Plant seedlings 12 to 18 inches apart, allowing room for growth. These are large plants, growing up to 4 feet tall and 18 inches wide. Hybrids such as "Byron Flint" (Salvia mexicana x hispanica) grow up to 6 feet tall and 3 feet wide. Although drought resistant, chia thrives when watered regularly and especially if the soil is dry to the touch.

Blue to lavender flowers begin appearing in July and August, four months after germination. They attract native bees, honeybees, butterflies, and hummingbirds. Once pollinated, the flowers die back and the tiny seeds develop. Deadhead the flowers to encourage continued blooming until frost. If the plant goes to seed, sparrows and other seed-eating birds will eat them.

(Growing instructions via https://homeguides.sfgate.com/long-chia-sprout-turn-flower-82587.html)