- Vanillin and marker compounds
- Vanillin, p-hydroxybenzaldehyde, vanillic acid and p-hydroxybenzoic acid by HPLC; their ratios are the usual screen for added synthetic vanillin.
- Alcohol content
- Ethanol percent by volume by GC or density; 35% is the minimum for anything labeled vanilla extract.
- Authenticity by isotope ratio
- Carbon-13 (and sometimes deuterium) isotope ratio analysis of the vanillin, which separates bean vanillin from vanillin made from guaiacol, lignin or ferulic acid.
- Coumarin and ethyl vanillin
- A check that coumarin and ethyl vanillin are absent, by HPLC or GC-MS, especially for low-priced or imported extracts.
- Physical and micro
- Color, specific gravity and total plate count, yeast and mold for lower-alcohol flavorings, which are more open to spoilage.