White crystalline powder
A disaccharide commonly found in foods and commonly utilized in brewing processes.
Purify maltose by chromatography from aqueous solution on to a charcoal/Celite (1:1) column, wash it with water to remove glucose and other monosaccharides, then elute it with aqueous 75% EtOH. Crystallise it from water, aqueous EtOH or EtOH containing 1% nitric acid. Dry it as the monohydrate at room temperature under vacuum over H2SO4 or P2O5. Also purify it by dissolving it in MeOH, evaporating to a syrup which on standing for 12hours in contact with 1/10th its volume of H2O gives crystals of the monohydrate. Its iodine number is 55.5. The osazone has m 200o(dec) and  D 20 +58o (c 1.4, H2O). [Howarth et al. J Chem Soc 793 1937, Beilstein 17 III/IV 3057, 17 V 189.]