How MSG Is Made: Raw Materials and Production Process

What is MSG and how is it made?

Monosodium glutamate, or MSG, is a flavor enhancer made through fermentation of carbohydrate sources such as sugarcane molasses, corn starch, or tapioca starch. The production process uses bacteria to convert sugars into glutamic acid, which is then neutralized with sodium hydroxide, purified, and crystallized into the white crystals we use in cooking. This method is similar to making yogurt, beer, or soy sauce, and the result is a pure compound that adds umami—the savory fifth taste—to dishes.

MSG is the sodium salt of glutamic acid, an amino acid found naturally in many foods like tomatoes, cheese, and mushrooms. In Thailand, MSG is often used in small amounts to round out flavors in soups, stir-fries, and dipping sauces, complementing the balance of salty, sweet, sour, and spicy.

Raw Materials for MSG Production

The key raw materials for MSG production are carbohydrate sources, nitrogen sources, minerals, and the microorganism used for fermentation. In India, where MSG is also produced, common carbohydrate sources include sugarcane molasses, corn starch, and tapioca starch—all readily available and cost-effective.

• Carbohydrate sources: These provide the sugar that bacteria feed on. Examples: sugarcane molasses, corn starch hydrolysate, tapioca starch hydrolysate.
• Nitrogen sources: Often ammonium salts or urea, which supply nitrogen for bacterial growth and glutamic acid synthesis.
• Minerals and vitamins: Trace amounts of phosphates, magnesium, and B-vitamins support fermentation.
• Microorganism: Specific strains of Corynebacterium glutamicum are used because they efficiently convert sugars into glutamic acid.

MSG Production Process Step by Step

The industrial production of MSG involves several distinct stages. Each step is carefully controlled to ensure high yield and purity.

1. Preparation of carbohydrate source: Starch is broken down into glucose using enzymes or acid hydrolysis. Molasses is diluted and treated to remove impurities.
2. Fermentation: The sugar solution is placed in large fermentation tanks. The selected bacteria (Corynebacterium glutamicum) are added under sterile conditions, along with nitrogen sources and minerals. The mixture is aerated and kept at around 30–37°C for 24–48 hours. During this time, the bacteria convert glucose into glutamic acid, which is secreted into the liquid.
3. Recovery of glutamic acid: After fermentation, the broth contains glutamic acid. The liquid is filtered to remove bacterial cells. The pH is then adjusted to precipitate glutamic acid crystals, which are separated by centrifugation or filtration.
4. Neutralization: The glutamic acid is mixed with sodium hydroxide to form monosodium glutamate (MSG) in solution.
5. Purification: The MSG solution is decolorized using activated carbon and filtered to remove impurities.
6. Crystallization: The purified solution is concentrated under vacuum to induce crystallization. The crystals are separated, dried, and sieved to achieve uniform size.
7. Final packaging: The finished MSG crystals are packaged in sachets, bags, or bulk containers for distribution.

The result is a white, odorless crystalline powder that dissolves easily in water. It has a pure umami taste, without any off-flavors.

MSG Production in India

India is one of the countries where MSG is manufactured, using locally available raw materials. Producers use molasses from sugar refineries or starch from corn and tapioca. The fermentation process is similar to that used worldwide, with Corynebacterium glutamicum strains adapted to local substrates. Indian companies like Ajinomoto India Pvt. Ltd. and local manufacturers follow food safety regulations set by FSSAI. The production capacity in India meets domestic demand, and some MSG is also exported. The use of non-GM bacteria and traditional fermentation methods ensures the MSG is identical to that produced elsewhere.

MSG in Thai Cooking: A Sensory Guide

In Thai cuisine, MSG is sometimes used alongside fish sauce, soy sauce, or shrimp paste to boost umami. It appears as fine white crystals, similar to salt but with a different taste. When you taste a tiny amount, it is not salty but rather savory and mouth-filling. In a dish like tom yum soup, MSG helps harmonize the hot and sour flavors, making the broth taste richer without adding saltiness.

Visually, MSG crystals are uniform and shiny, unlike flaky sea salt or coarse sugar. They dissolve quickly in hot liquids, leaving no residue. In stir-fries, MSG is added near the end of cooking to preserve its flavor-enhancing effect. A good substitute for MSG in Thai recipes is a small amount of fish sauce or soy sauce, but these add liquid and salt, so adjustments are needed. Another option is to use a pinch of sugar and a drop of fish sauce to mimic umami, but the result is not as clean.

Comparison: MSG vs. Other Seasonings

Simple Tips for Using MSG at Home

When using MSG in Thai cooking, start with a very small amount—about 1/8 teaspoon for a dish serving four. Add it along with other seasonings, then taste and adjust. MSG works best in dishes with some liquid, such as soups, curries, or sauces, where it can dissolve and meld. For dry stir-fries, dissolve MSG in a tablespoon of water or sprinkle it over the dish while cooking. Remember that MSG does not replace salt; it enhances the savory notes, so you might still need a little salt or fish sauce for balance. If you prefer to avoid MSG, use a combination of fish sauce and a pinch of sugar to add depth, but note that this will alter the dish's liquid content and saltiness.