What Happens to Lactose During Cheesemaking?
Contrary to popular belief, most cheese contains very little to no sugar, or lactose, by the time it reaches your plate. The process begins with fresh milk, which is rich in lactose. Cheesemakers add a starter culture of beneficial bacteria, which begins the critical process of converting the milk sugar into lactic acid. This acidification is what gives many cheeses their distinctive tangy flavor and helps to set the curd.
Following the acidification, rennet is added to coagulate the milk, causing it to separate into solid curds and liquid whey. A large portion of the lactose, being water-soluble, is drained away with the whey. This single step removes a significant amount of the milk sugar before the cheese even begins to age. For harder, aged cheeses, more whey is drained, resulting in a lower initial lactose content.
The Role of Aging in Reducing Lactose
After the curds are formed and separated, the remaining lactose is further consumed by the starter culture bacteria during the maturation phase. The longer a cheese is aged, the more time the bacteria have to ferment any remaining milk sugar. This is why aged cheeses are particularly low in lactose.
- Long-aging: Cheeses aged for many months or years, such as Parmesan and aged cheddar, have virtually no measurable lactose left.
- Whey drainage: Cheeses where a large amount of whey is drained off, like Swiss and Gouda, also end up with negligible lactose.
- Lactic acid conversion: The conversion of lactose into lactic acid makes the final product safe for many people with lactose intolerance.
Hard vs. Soft Cheese: A Comparison of Lactose Content
Different types of cheese have varying levels of lactose based on their production and aging methods. The amount of whey that is drained and the length of the aging process are the primary determining factors.
| Cheese Type | Examples | Lactose Content | Reason for Content Level |
|---|---|---|---|
| Hard, aged | Parmesan, Aged Cheddar, Swiss, Gouda | Negligible (less than 0.1g per 100g) | Long aging allows bacteria to consume nearly all residual lactose. |
| Semi-hard | Gruyère, Edam, Mimolette | Very low (often trace amounts) | Aged for months, allowing significant lactose breakdown. |
| Soft, ripened | Brie, Camembert | Low (1-2g per 100g) | Ripened for less time, so some lactose may remain. |
| Fresh | Ricotta, Cottage Cheese, Cream Cheese | Higher (2-5g per 100g) | Minimal aging or fermentation means most lactose is retained. |
Can Lactose-Intolerant Individuals Eat Cheese?
For most people with lactose intolerance, consuming aged, hard cheeses is generally safe and causes no symptoms. This is because the lactose is largely broken down during production. However, tolerance levels vary significantly, so it is important for individuals to determine their own personal limit. Softer, fresh cheeses will contain more lactose and may cause digestive issues for sensitive individuals. Some people may also be sensitive to dairy proteins rather than just lactose, so understanding one's specific intolerance is key.
For those who are particularly sensitive, options include consulting a cheesemonger for specific product details or choosing cheeses explicitly labeled "lactose-free." Many dairy companies now use an enzymatic process during manufacturing to ensure a completely lactose-free product. Another approach is to take a lactase enzyme supplement before eating dairy, which helps the body digest the lactose.
The Journey from Milk to Nearly Sugar-Free
The transformation of milk's natural sugar, lactose, into lactic acid is a cornerstone of the cheesemaking craft. It's a natural, bacterial process that creates not only complex flavors and textures but also makes dairy products more accessible to those with lactose intolerance. From the initial curdling of milk to the final, long-term aging, each step works to reduce the lactose content. The result is a delicious food with surprisingly little sugar.
Ultimately, understanding the journey of lactose in cheese empowers consumers to make informed decisions about their diet. Whether you are managing an intolerance or are simply curious about the science behind your favorite food, the answer to what is the sugar in cheese called is simple: lactose, but only at the very beginning of its life. For those seeking low-lactose choices, the best approach is to choose hard, mature varieties where the natural process of aging has done most of the work. You can explore a wide variety of cheeses at your local market or speak with a knowledgeable cheesemonger for personalized recommendations.
A Deeper Dive into Fermentation
Fermentation is not only responsible for removing lactose but also for developing the complex flavors found in aged cheeses. The lactic acid produced influences the final acidity, texture, and taste profile. As bacteria continue to break down compounds during aging, new flavor notes emerge, and the texture can transform from soft and moist to firm and crumbly. This microbial activity is the true magic behind cheese, converting a simple ingredient like milk into thousands of unique products loved around the world.
