Monosodium glutamate (MSG) is a popular food additive that lends umami (savory) flavor. Do pure MSG crystals require a hechsher?
The OU writes:
Another category change involves fermentation products such as citric acid, lactic acid, and monosodium glutamate. These products are produced by growing certain microorganisms (fungi, bacteria, and yeasts) in large tanks called fermentors. Ingredients in the fermentor, as well as those which are used to grow the microorganism in early stages, can pose Kashrus concerns. Such ingredients can include beef extracts, porcine extracts, casein hydrolyzed with animal enzymes, and animal fat based antifoams. While many of these ingredients may be Batul, the OU has worked with a number of companies to produce these items without Sheilos. The OU therefore requires a reliable supervision for these products to ensure that they are Kosher L’Chatchila.
Monosodium Glutamate (MSG) is produced through a fermentation process of molasses or beets and is a flavor enhancer in soups, meats and sauces. MSG requires reliable kosher certification.