flax seed eggs

The outermost layer of flax seeds, called the epiderm, contains a mucilaginous material which makes up about 8% of the flax seed by weight. This gel-like material is drawn out of the seed in several ways and used as an egg replacement. Flax gel is a hydrocolloid, a substance that forms a gel when combined with water. Hydrocolloids usually work either to build structure, to emulsify and to soften 'mouthfeel'.

Flax gel is made up of mainly polysaccharides (type of starch), which consist of a continuous strings of monosaccharides, or single sugars like glucose and fructose. Polysaccharides are important in foods because they are exceptional at holding onto water molecules. Their long sugar strings also bump and tangle into each other when poured which causes them to increase the viscosity of water-based fluids. Polysaccharides are also responsible for the thickness of molasses and why brown sugar retains more water to make for chewier cookies. Flax gel can work as a mild structure builder, low foaming agent and emulsifier in vegan baking applications. NOTE: Flax eggs will never perform exactly like eggs, because they rely on proteins to do most of their work and flax seeds use polysaccharides.

Flax seed meal egg : Quicker to make, used for added moistness and denseness but imparts more flavor and isn't ideal as a structure builder in cakes, it's also not ideal when a uniform light color is desired as the flax seed particles will have golden flecks.
How-to : 45 ml (3 tbsp) water + 15 g (1 tbsp) golden flax meal = 1 egg. Add the water to a small bowl or cup. Add flax meal and mix together with a whisk or fork. Let the mixture sit for about 10 minutes so it develops a gelatinous texture similar to a raw egg. Warm water will speed up this gelling process and make it happen about twice as fast.

Flax gel egg replacer : Performs like an actual egg due to its translucence, doesn't impart as much flax flavor, adds extra binding and emulsifying power (for cookies, bars and ice creams). This technique is more involved, and harder to measure because flax gel is very viscous and elastic.
How-to: 45 ml (3 tbsp) flax gel = 1 egg. To make flax gel, you need 700 ml (3 cups) of water and 50 g (5 tbsp) of flax seeds. To make it, boil the flax seeds till reduced to a third of its volume. Strain seeds through a strainer, collect gel underneath. Allow mucilage to cool. Makes 1 cup of flax gel. [ref]