Cheddar cheese, in its most traditional form, is a fermented, natural food that relies on a specific production process rather than synthetic preservatives for its longevity. However, the modern marketplace offers a wide range of cheddar products—from artisan blocks to convenient pre-shredded bags and processed cheese foods—and each comes with a different story regarding its preservation methods.
The Natural Preservation of Traditional Cheddar
Hard, aged cheddar, like a block of sharp English cheddar, possesses a naturally long shelf life due to several inherent properties that act as preservatives.
Low Moisture Content
Hard cheeses like cheddar have a low moisture content, which is a major deterrent to microbial growth. The process of cheesemaking involves removing whey from the curd, resulting in a dense block of cheese that contains little free water for bacteria and mold to thrive on.
Salt and Acidity
Salt is a crucial component in cheddar production. It is added to the cheese curds after the milling process to inhibit the growth of unwanted microorganisms while encouraging the beneficial bacteria responsible for aging and flavor development. The resulting acidity from the cheese cultures also creates an environment that is hostile to most spoilage-causing microbes.
The Aging Process
Aged cheddar can last for months or even years, and this is by design. The long aging process further reduces moisture and develops a protective rind. This natural process is what gives aged cheddar its distinctive sharp flavor, without needing any added chemical preservatives.
Added Preservatives in Processed and Shredded Cheddar
Unlike traditional block cheddar, many convenience-focused products contain chemical preservatives to serve a specific function.
Natamycin (E235)
Natamycin is a natural antifungal agent produced by soil bacteria and is widely used in the food industry to prevent mold and yeast growth on the surface of cheese. It is often applied as a surface spray or incorporated into the rind of hard and semi-hard cheeses like some cheddars. For shredded cheese, it can be added to the packaging to inhibit mold growth. Natamycin is particularly effective because it does not penetrate deeply into the cheese, ensuring the flavor is unaffected.
Anti-caking Agents
Pre-shredded cheddar often contains anti-caking agents like potato starch or powdered cellulose. These aren't preservatives in the microbial sense, but they are additives that serve to maintain product quality by preventing the shreds from clumping together in the bag.
Sorbates and Benzoates
Processed cheese foods and spreads, which often contain cheddar as an ingredient, may use preservatives like potassium sorbate and sodium benzoate. These additives are especially useful in products with higher moisture content and serve to inhibit mold and yeast growth throughout the product.
Understanding the Product Label
For consumers, the most reliable way to know what's in your cheddar is to read the ingredient list. An aged, block cheddar will typically list only a few core ingredients: pasteurized milk, cheese culture, salt, and enzymes. A bag of shredded cheddar, by contrast, may include additional items like natamycin and cellulose. Processed cheese products are often the most complex, with multiple emulsifiers and preservatives added.
Comparison Table: Natural vs. Processed Cheddar
| Feature | Traditional Block Cheddar (Natural) | Processed/Shredded Cheddar |
|---|---|---|
| Preservation Method | Low moisture, high salt, aging process | Added preservatives (e.g., natamycin) and packaging technology |
| Additives | Typically none added (beyond cultures, salt, rennet) | Anti-caking agents (cellulose), mold inhibitors (natamycin, sorbates) |
| Texture | Firm and smooth, can become crumbly and crystalline with age | Softer, consistent, melts differently due to additives |
| Flavor | Develops depth and sharpness over time during aging | Uniform flavor, designed to be consistent from batch to batch |
| Shelf Life (Refrigerated) | Longer (months to a year for unopened aged blocks) | Shorter once opened (a few weeks) |
Conclusion
In summary, the question of whether cheddar contains preservatives has a nuanced answer that depends on the specific product. A hard, aged block of traditional cheddar relies on natural attributes—low moisture, salt, and fermentation—to stay preserved. In contrast, commercially produced shredded cheese and processed cheese products commonly use added preservatives, such as natamycin and anti-caking agents, to prevent spoilage and clumping. By checking the label, consumers can easily determine the preservation methods used for their chosen cheddar and make an informed decision based on their dietary preferences.
Visit the Ask USDA website for official guidance on food safety.
