Why Treat Corn with Lime?
Corn is treated with lime because it helps remove the hulls and softens the kernels. Treating with lime also makes niacin more available and improves digestion. For thousands of years, people in Central America have soaked corn in water mixed with calcium hydroxide or "lime" to process it into dough and flour, making nutrients more accessible.
The Process of Nixtamalization
Nixtamalization is a traditional process in Mexico and Central America whereby corn is treated with lime, cooked, and dried and ground to produce the flour used to make tortillas. The alkalinity of lime helps dissolve hemicellulose in maize cell walls, loosening hulls and softening the maize. About 1% lime by weight of corn is typically used in this process.
Soil pH and Lime Application
A soil pH of 6.0-7.0 is preferred for sweet corn. Lime (if needed) is most effective when worked into the soil in the fall. Many nutrient deficiency symptoms are often due to low pH, so applying the appropriate fertilizer is essential as well.