The Crucial Ingredient: Rennet
At the heart of the debate over whether mozzarella string cheese is vegetarian lies a single, vital component: rennet. Rennet is a complex mixture of enzymes, most notably chymosin, used to curdle milk, separating it into solid curds and liquid whey during the cheesemaking process. The source of this rennet determines if the final cheese product is suitable for vegetarians.
Animal vs. Vegetarian Rennet
Traditionally, rennet is harvested from the stomach lining of young calves, lambs, or goats. Since this is a byproduct of slaughter, cheese made with animal rennet is not considered vegetarian. For many years, this meant that vegetarians had to avoid a wide range of cheeses. However, advancements in food science have provided viable alternatives.
Today, most commercial cheesemakers use vegetarian-friendly coagulants. The primary alternatives include:
- Microbial Rennet: Derived from molds, fungi, or bacteria, this is the most common vegetarian rennet used in cheese production today. It is a reliable and cost-effective alternative to its animal-derived counterpart.
- Vegetable Rennet: Sourced from specific plants like thistles, artichokes, or figs, vegetable rennet is less common than microbial rennet but is still used by some cheesemakers. Some varieties, however, can impart a bitter flavor to aged cheeses.
- Fermentation-Produced Chymosin (FPC): This is a genetically engineered version of chymosin produced by microbes, which is now used in over 90% of cheese production. While its status as 'vegetarian' is accepted by many, its GMO origin is a point of contention for some stricter vegetarians.
Decoding the Ingredient Label
The easiest way to determine if a mozzarella string cheese product is vegetarian is to read the ingredient list carefully. The wording can sometimes be vague, but there are specific terms to look for:
What to Look For
- "Microbial enzymes": This indicates the use of vegetarian rennet derived from microorganisms.
- "Vegetarian enzymes": This is a straightforward label that guarantees the coagulant is not animal-based.
- Kosher Certification: Products certified as Kosher often use microbial rennet, as animal rennet from non-Kosher sources is forbidden. Look for a 'K' or 'OU' symbol on the packaging.
- Specific Brand Information: Many brands explicitly state "suitable for vegetarians" or "made with vegetarian rennet" on their packaging.
What to Avoid
- "Rennet": If the label simply says "rennet" or "enzymes" without specifying "microbial" or "vegetarian," it is safest to assume it contains animal rennet.
- "Animal enzymes": This is a direct indication that the cheese is not vegetarian.
- Animal Lipase: While less common, lipase is another enzyme sometimes added for flavor and can be animal-derived. Check for "microbial lipase" if listed.
Vegetarian and Non-Vegetarian Coagulants in Cheese
This comparison table illustrates the differences between various coagulant types used in cheesemaking.
| Coagulant Type | Source | Vegetarian Status | Notes |
|---|---|---|---|
| Animal Rennet | Stomach of young mammals (calf, lamb, kid) | No | Traditional, still used in some artisanal cheeses. |
| Microbial Rennet | Fungi, mold, bacteria | Yes | Most common coagulant in commercial cheese production. |
| Vegetable Rennet | Plants (e.g., thistle, artichoke, fig) | Yes | Used in some European and artisan cheeses. |
| Fermentation-Produced Chymosin (FPC) | Genetically modified microbes | Yes (generally) | Widespread, but may be avoided by stricter vegetarians. |
| Acid Coagulation | Citric acid, vinegar | Yes | Used for fresh cheeses like ricotta and paneer, not string cheese. |
How String Cheese Is Made
The unique, peelable texture of string cheese is a result of a specific step in the cheesemaking process involving heating and stretching the mozzarella curd. This mechanical alignment of milk proteins is what gives string cheese its characteristic strands. While the stretching process itself is vegetarian, it's the initial coagulation step—where rennet is added to curdle the milk—that determines the cheese's final vegetarian status. The type of rennet used by the manufacturer is independent of the mechanical stretching that follows.
Common Vegetarian String Cheese Brands
Thankfully, with the rise of vegetarianism, many major brands now offer string cheese suitable for this diet. Some popular choices known to use vegetarian-friendly enzymes include:
- Organic Valley Stringles: As a USDA Certified Organic product, their string cheese is guaranteed to be suitable for vegetarians.
- Frigo Cheese Heads: Many of their products are made with microbial enzymes, but always check the specific label to be sure.
- Sargento String Cheese: Like Frigo, many Sargento string cheese varieties are vegetarian, and their labels typically list "microbial enzymes".
- 365 Whole Foods Market: The store brand often offers vegetarian and non-GMO string cheese options.
Conclusion: Always Verify the Ingredients
Is mozzarella string cheese vegetarian? The answer is: often, but not always. While the majority of mass-produced cheese now uses non-animal rennet, variations exist between brands and product lines. For vegetarians, developing the habit of checking the ingredient list is the most reliable method for ensuring a product aligns with their dietary choices. Pay close attention to the terms "enzymes" or "rennet," and opt for products that specify "microbial" or "vegetarian" enzymes or carry a vegetarian certification logo. For more information on ingredients, consider checking resources like the Vegetarian Resource Group blog. A little research at the store can save you from an accidental transgression and allow you to enjoy your string cheese with peace of mind.
