Aldol reactions may be carried out without use of preformed enolates simply by grinding together solid reagents in the presence of NaOH. No organic solvent (unless product recrystallisation is required) is utilised in the reaction and the only waste produced is a small amount of acidic aqueous waste. Single crossed aldol condensation products are produced in high yields even in reactions where a mixture of products is possible. These reactions are highly atom and energy efficient and are highly chemoselective. An additional advantage is the high stability of the reaction mixture, which may be stored for a lengthy period.