What Is Food Grade Lime Culinary Uses And Safety?

What Is Food Grade Lime and How Is It Different from Other Limes?

Food grade lime is calcium hydroxide. It is also called pickling lime or slaked lime. Manufacturers heat limestone to create calcium oxide, then add water to produce calcium hydroxide. The result is a fine white powder.

This is not the same as the lime you buy at the grocery store. The green citrus fruit is called lime but contains citric acid. Food grade lime is an alkaline mineral. They are completely different substances with different uses.

It is also not the same as agricultural lime or construction lime. Those products may contain impurities or heavy metals that are dangerous to eat. Only food grade lime is tested and approved for human consumption. The label must say “food grade” or “pickling lime” to be safe.

What Are the Main Culinary Uses for Food Grade Lime?

The most common use for food grade lime is nixtamalization. That is the traditional process of soaking dried corn in an alkaline solution. The calcium hydroxide breaks down the corn’s outer hull. This makes the corn easier to grind into masa for tortillas, tamales, and other dishes.

Nixtamalization also makes the nutrients in corn more available to your body. Without this process, the niacin in corn remains bound up and your body cannot absorb it well. The CDC reports that nixtamalization was a key cultural practice in Mesoamerica that prevented niacin deficiency.

Another common use is pickling. Food grade lime helps keep pickles crisp. When you soak cucumbers in a lime solution before pickling, the calcium strengthens the cell walls. This prevents the pickles from turning soft or mushy during storage.

Some people use food grade lime for making hominy. Hominy is dried corn that has been treated with an alkali. It has a distinct chewy texture and nutty flavor. You can find it in soups, stews, and side dishes.

Food grade lime is also used in some traditional recipes for preserving fruits and vegetables. It can help maintain color and texture in canned goods. Some cultures add small amounts to certain dishes as a calcium supplement.

Is Food Grade Lime Safe for Consumption?

Yes, food grade lime is safe when used correctly. The U.S. Food and Drug Administration (FDA) recognizes calcium hydroxide as Generally Recognized as Safe (GRAS) for food use. But there are important rules to follow.

You must only use food grade lime. Never use construction lime, garden lime, or any other type. These products can contain lead, arsenic, or other toxic substances. The label must clearly state it is for food use.

You also need to use the right amount. Food grade lime is very alkaline with a high pH. Consuming too much can cause burns to your mouth, throat, and stomach. It can also lead to a condition called milk-alkali syndrome, which causes dangerously high calcium levels in your blood.

Always follow the recipe instructions carefully. For nixtamalization, the typical ratio is about one tablespoon of food grade lime per pound of dried corn. You rinse the corn thoroughly after soaking to remove excess lime. For pickling, you soak the cucumbers and then rinse them before processing.

What Does Research Show About Food Grade Lime?

Research published in the Journal of Food Science shows that nixtamalization with calcium hydroxide significantly increases the calcium content of corn. The treated corn can have up to 20 times more calcium than untreated corn. This is one reason why traditional diets that use nixtamalization often provide adequate calcium without dairy.

Studies have also found that nixtamalization reduces certain antinutrients in corn. Phytic acid, which blocks mineral absorption, is lowered by the alkaline treatment. This makes the iron and zinc in corn more available to your body.

Some research suggests that food grade lime may have antimicrobial properties. A study in the International Journal of Food Microbiology found that calcium hydroxide solutions can inhibit the growth of certain bacteria and fungi. This may explain why it has been used for food preservation for centuries.

However, most of the research focuses on nixtamalization specifically. There are fewer studies on other culinary uses like pickling. The evidence for crisping pickles comes largely from traditional knowledge and food science principles rather than large clinical trials.

What Are the Potential Side Effects and Risks?

The main risk is using the wrong type of lime. Non-food grade lime can contain harmful contaminants. Always buy from a reputable source and check the label.

Eating too much food grade lime can cause digestive upset. Some people report nausea, stomach pain, or diarrhea after consuming improperly rinsed nixtamalized corn. This is usually because excess lime was not washed off.

Contact with dry powder can irritate your skin and eyes. Wear gloves and a mask when handling food grade lime. If you get it in your eyes, flush with plenty of water and seek medical help.

People with kidney disease should be cautious. The high calcium content of treated foods may be too much for damaged kidneys to process. If you have kidney issues, talk to your doctor before eating foods made with food grade lime.

For most healthy adults, the amounts used in cooking are safe. The key is moderation and proper rinsing. A typical serving of tortillas or hominy contains only trace amounts of residual lime.

Food Grade Lime vs. Other Common Food Additives

| Substance | Source | Common Use | Safety |
|———–|——–|————|——–|
| Food grade lime (calcium hydroxide) | Processed limestone | Nixtamalization, pickling | GRAS by FDA when food grade |
| Baking soda (sodium bicarbonate) | Mined or manufactured | Leavening, cleaning | Safe in typical amounts |
| Pickling salt (sodium chloride) | Evaporated seawater | Pickling, preserving | Safe, no additives |
| Alum (potassium aluminum sulfate) | Mined mineral | Crisping pickles | Controversial, some avoid |
| Calcium chloride | Brine or manufactured | Firming vegetables, cheese making | GRAS by FDA |

This table shows that food grade lime is one of several options for food processing. Each has different properties. For crisping pickles, calcium chloride is a more modern alternative that does not require rinsing.

How to Use Food Grade Lime Safely at Home

If you want to try nixtamalization at home, start with dried field corn, not sweet corn. Here is the basic process:

• Rinse the dried corn and remove any debris.
• Dissolve food grade lime in water. Use about one tablespoon per pound of corn.
• Add the corn and bring to a boil. Simmer for 30-45 minutes.
• Turn off the heat and let the corn soak for 4-12 hours.
• Drain and rinse the corn thoroughly. Rub the kernels to remove the loosened hulls.
• Rinse several times until the water runs clear and the corn no longer feels slippery.

For pickling, dissolve one tablespoon of food grade lime per gallon of water. Soak cucumbers for 12-24 hours in the refrigerator. Rinse them very well before pickling. Do not skip the rinsing step.

Store food grade lime in a sealed container in a cool, dry place. Keep it away from moisture because it can absorb water from the air. Label it clearly so no one mistakes it for flour or sugar.