A very standard formula for the French meringue style of macaron recipe is approximately 1.25:2.3:1.0:0.3 (almond:icing sugar:egg white:caster sugar). Variants of this are used by Alain Ducasse, Christophe Felder, J.M.Perruchon & G.J.Bellouet and Dean Brettschneider. Pierre Hermé’s formul...