Is it scientific fact that acid stabilizes meringue or is this a
fallacy? If so does anyone know actually why and are there any
other substances that do this well also? Acids allow more air to
be beaten into a meringue. In order to make meringue, the
proteins in egg white must be denatured. In their natural state,
the proteins are curled up into tightly packed balls. When the
egg is beaten, they uncoil into long strands. These strands then
begin to coagulate, or join together, with the help of the sugar
you add. The air you whisk in gets trapped between these joining
strands, giving the meringue its characteristic light texture.
Acid delays coagulation, which means that there is more time for
air to get trapped in amongst the proteins, resulting in a
lighter meringue. The acids usually added to meringue are white
wine vinegar, lemon juice, or cream of tartar. Fresh eggs are
more acidic than old ones, so these help too. Some cooks use
copper bowls to make meringue, because copper ions from the bowl
bind to a p