Aquafaba
The viscous water from cooked or canned chickpeas, which whips into a foam resembling egg white — with performance that varies substantially between brands.
Also called chickpea water (INTERNATIONAL); bean water (INTERNATIONAL)
Aquafaba is the liquid chickpeas have been cooked in, carrying dissolved protein, carbohydrate and saponins. Whipped, it forms a foam that looks remarkably like whisked egg white, and it is the only widely available egg replacement that aerates at all.
What it does not do is as important. It supplies almost no protein by comparison with egg, so it contributes little coagulated structure; it has no fat and no yolk emulsifiers; and it browns far less. It is a replacement for the AERATION function of egg white specifically, and treating it as a general egg substitute produces flat, pale, fragile results.
It is also the least consistent ingredient on this list. Measured across ten commercial products, foam volume and stability varied significantly, and after an hour the foam had collapsed and separated in every brand but one.
Composition and specification
Variability between brands
Freeze-dried aquafaba protein content ranged from 23.3% to 26.8% across commercial products, and the coefficient of variation for viscosity across brands was 160%. Foam volume and stability varied significantly, with liquid separating from the foam of every brand but one within an hour.
Recorded as the headline fact about aquafaba rather than a footnote to it. A reader whose meringue failed has most likely not made a mistake — they have used a different tin.
What changes if it is left out
Nothing is lost that another aerating route cannot supply. Aquafaba is itself a substitution, so its absence matters only where egg is also absent and aeration is required — in which case the alternatives are chemical leavening or a formulation that does not need a foam.
Follows from the substitution model rather than being an independent claim.
RecordedFollows from evidence recorded elsewhere on BakeHQ
What the evidence does and does not establish
The measured study behind this record characterises what aquafaba is and how much it varies. It contains no controlled comparison against egg white in a real bake. So BakeHQ states that aquafaba foams, that its performance varies substantially by product, and nothing about how closely it matches egg white — because that comparison has not been read at passage level. The open verification item is recorded on the sources page.
Related
What it does
Aeration
The only widely available egg replacement that aerates at all. Its foam volume and stability vary substantially between commercial products, which is measured rather than anecdotal.
Can stand in for
Eggs— for the aeration of egg WHITE, and nothing the yolk did
The only replacement that whips to a comparable foam. It contributes almost no coagulating protein, no fat, no emulsifier and little browning — so it replaces a whisked white and not a whole egg. Expect substantial variation between brands: measured across ten products, foam stability differed enough that all but one collapsed within an hour.