How vegan eggs are made: mung beans, fermented ovalbumin, and the chemistry of each

A chicken egg is not one ingredient functionally, it is five. It binds ingredients together, it leavens through trapped air in whipped whites, it emulsifies fat and water into a stable mixture, it sets and firms when heated (coagulation), and it enriches a dish with fat, colour and flavour. A cake recipe might be asking an egg to do three of those jobs in one bowl. No single plant compound performs all five at once, and that mismatch is why vegan egg replacers are not one product. They are a family of narrow tools, each built to do one or two of the five jobs and nothing else.

That is also why the category split cleanly in two. Liquid egg substitutes such as JUST Egg exist to replicate coagulation and enrichment, the behaviour of a scramble or omelette going from liquid to solid over heat. Powdered and improvised replacers exist to replicate binding and leavening in baked goods, where nothing needs to set into curds. Reaching for the wrong one in the wrong recipe is why a flax egg fails to make an omelette and why JUST Egg makes an odd, gummy brownie.

JUST Egg, made by Eat Just, is a liquid egg substitute built around mung bean protein isolate. The company has said its scientists screened hundreds of thousands of plant species, a figure the company has put at roughly 357,000, looking for one whose protein would gel like egg white when heated. Mung bean stood out because its dominant storage protein, an 8S globulin, denatures and forms a firm gel in a temperature range that overlaps with the two proteins that make egg white set: ovotransferrin, which coagulates starting around 61C, and ovalbumin, egg white's most heat-stable protein, which fully sets around 80C. Published gelation studies on mung bean protein isolates put its structuring range in the roughly 70C to 85C band, which is close enough to that egg-white window that a mung bean scramble firms into curds on a hot pan the way an egg does, rather than staying a wet paste or turning rubbery.

Eat Just submitted its mung bean protein isolate to the FDA as a GRAS (generally recognized as safe) ingredient in December 2016, under the company's earlier name, Hampton Creek, and received the FDA's no-questions response. The finished JUST Egg formula lists water, mung bean protein isolate and expeller-pressed canola oil as its three largest ingredients by weight. Gellan gum, a fermentation-derived polysaccharide, adds body and helps the liquid hold together before it hits the pan. Small amounts of turmeric and carrot extractives supply the yellow colour a real yolk would otherwise provide, since mung bean protein on its own is pale. Nutritionally the swap is not free: a 3-tablespoon serving of JUST Egg carries about 5 grams of protein against roughly 6 grams in a large chicken egg, and it has no natural cholesterol or the choline a yolk carries, so it is a different nutrient profile rather than a strict substitute.

Mung bean is not the only protein used to build a settable liquid egg. Several products use soy protein isolate or pea protein isolate for the same coagulating job, sometimes blended with mung bean or with each other, since both legume globulin families denature and gel under heat in roughly the same range. Follow Your Heart's VeganEgg took a different route entirely, building its structuring protein from whole algal flour, a dried biomass of microalgae, combined with carrageenan and gellan gum for gelling and cellulose gum for body. Companies including Triton Algae Innovations have pursued algae further upstream, growing strains of the freshwater alga Chlamydomonas reinhardtii in fermentation tanks specifically to harvest proteins with gelling and foaming behaviour for egg and dairy analogues, positioning algae as a raw ingredient supplier rather than a finished-product brand.

The oldest manufacturing route of all predates every one of these companies by centuries: besan, or chickpea flour, ground from dried chickpeas and a staple of Indian, Middle Eastern and Mediterranean cooking long before anyone called it an egg substitute. Whisked with water into a batter, besan's chickpea protein and starch bind and firm on a hot pan much like a thin omelette, which is why besan chilla, a savoury chickpea pancake, functioned as an egg-free breakfast in parts of India well before the modern vegan-egg category existed. It is a coarser, less egg-mimicking texture than JUST Egg's globulin gel, but it needs no isolate, no gum and no factory, only flour and water.

A separate branch of the category does not simulate egg protein at all, it produces the actual molecule. The EVERY Company uses precision fermentation, inserting the genetic sequence for ovalbumin, the dominant protein in real egg white, into a microbial host that is then grown in a fermentation tank. The microbe manufactures ovalbumin as it grows, and the protein is purified out of the fermentation broth afterward. The result is not a plant protein standing in for egg white, it is molecularly the same ovalbumin a hen's oviduct produces, made without a bird. EVERY secured a foundational US patent covering fermentation-produced ovalbumin in September 2024 and its ingredient, now marketed as OvoPro (previously EVERY EggWhite), carries FDA clearance for food use. In March 2026, OvoPro reached home cooks directly for the first time through a partnership with Healthier Comforts, sold as a powdered pantry ingredient rather than only supplied to food manufacturers, and EVERY has said a manufacturing partnership with Huvepharma is meant to roughly quadruple its production capacity.

The improvised, no-brand-name replacers work through mechanisms that are as specific as anything in a factory formula. Aquafaba, the viscous liquid drained from a can of chickpeas, whips into a stable foam the way egg white does because it carries two active ingredients: low molecular weight proteins under about 24 kilodaltons, and saponins, plant compounds that behave like natural surfactants and produce a soap-like foam on their own. Research comparing aquafaba's isolated proteins to whole aquafaba has found the proteins alone foam worse than the mixture does, which points to saponins, not protein, as the larger driver of aquafaba's whipping behaviour, with the two likely interacting to stabilise the bubbles once formed. That foam is a leavening and emulsifying tool, not a coagulating one, so aquafaba fits meringues, mousses and cocktail foams, not scrambles.

Flax and chia seeds work by an entirely different mechanism: mucilage. Both seeds carry a layer of soluble polysaccharide in their hull that swells and thickens into a gel on contact with water, and that gel is a hydrocolloid, the same broad category of thickener as the gums used in commercial formulas. Whisked with water and left to sit, ground flax or whole chia builds a slippery, stretchy gel that binds particles together in a batter, standing in for an egg's binding role in muffins and cookies. Because it is a hydrocolloid rather than a heat-set protein, it does not firm up further when baked the way egg white does, and research on chia mucilage has found it can coat gluten strands and blunt gluten development, which is part of why a fully egg-free, flax-bound loaf tends to be denser than the same recipe made with eggs.

Vinegar and baking soda cover leavening alone and nothing else. Baking soda is sodium bicarbonate, a base; vinegar is acetic acid. Mixed together, the acid reacts with the base to release carbon dioxide gas on the spot, and that gas is what pushes a batter to rise while it is still liquid enough to trap the bubbles. It is the same acid-base leavening chemistry used in ordinary baking without eggs at all, borrowed here specifically for recipes that lean on egg foam for lift. It supplies no binding, no fat and no protein structure, which is why it is typically paired with a separate binder rather than used as a full egg swap on its own.

The manufacturing story behind each product maps directly onto where it belongs in a kitchen. A heat-set protein gel, whether it is mung bean, soy, pea, algal or fermented ovalbumin, is built for a pan: scrambles, omelettes, quiches, French toast batter. A hydrocolloid like flax or chia mucilage, or a starch-based powder, is built for an oven: cakes, muffins, cookies, quick breads, where binding matters more than setting into curds. Aquafaba sits in its own category, useful anywhere a recipe specifically wants trapped air: meringues, macarons, mousse, royal icing. Using a liquid protein substitute in a cake, or a flax egg in a scramble, is not a failure of the product, it is asking a tool to do a job its chemistry was never built for.

None of this manufacturing detail decides how much of each ingredient to use. For the actual swap ratios, tablespoon for egg, by recipe type, that is a separate, dedicated guide, and duplicating it here would only make both guides worse.