How the Cheesemaking Process Affects Lactose Content
Understanding how cheese is made is the first step to identifying low-lactose varieties. The key factors in reducing lactose are the separation of curds and whey, and the aging process.
- Curd and Whey Separation: In cheesemaking, milk is separated into solid curds and liquid whey. Lactose, being a water-soluble sugar, primarily stays in the liquid whey. For hard cheeses, the whey is drained more thoroughly, removing most of the lactose from the start.
- Fermentation and Aging: The starter cultures (beneficial bacteria) added to the cheese curds continue to ferment any remaining lactose, converting it into lactic acid. The longer a cheese is aged, the more time these bacteria have to consume the lactose, leading to minimal to non-existent levels in the final product. Some extra-mature cheeses, aged over 18 months, have been measured to contain virtually no lactose.
This process is why hard, aged cheeses are far lower in lactose than softer, fresh cheeses like ricotta, cottage cheese, or fresh mozzarella, which retain more moisture (whey).
Low-Lactose Cheeses Available in Sliced Form
While buying sliced cheese often means looking at packaged options, you can find low-lactose choices both pre-sliced and by slicing a block yourself. Some of the best options include:
- Aged Cheddar: Extra-sharp and mature cheddars are aged longer, resulting in very low lactose levels—often less than 0.1 gram per ounce for those aged over 12 months. Some brands like Cabot certify their aged cheddars as lactose-free.
- Swiss: Known for its characteristic holes and nutty flavor, traditional Swiss cheese (Emmentaler) is naturally very low in lactose due to its long aging. Deli-sliced Swiss, however, may have higher lactose if whey is added for texture, so look for authentic, aged varieties.
- Provolone: Aged provolone has a buttery flavor and low lactose content, making it a suitable option for sandwiches and melting. As with Swiss, be mindful of processed versions versus aged blocks.
- Gouda: Aged Gouda, often with caramel notes, contains very little lactose. The longer the aging process, the lower the lactose content. Look for labels indicating “aged” or “extra-aged” Gouda.
The Problem with Processed Cheese Slices
Processed cheese, including many types of American cheese slices, are often blended with other dairy ingredients, such as additional whey, to create their smooth, creamy texture and melting properties. This re-introduction of whey can increase the lactose content, making them less suitable for those with sensitivities compared to naturally aged cheeses. For example, studies have shown American processed cheese slices to have a higher lactose content than natural, aged cheeses.
Low-Lactose Sliced Cheese Comparison
| Cheese Type | Typical Lactose Content (per 100g) | Notes on Sliced Varieties |
|---|---|---|
| Extra-Aged Cheddar | <0.1g | The best choice; look for blocks or packaged slices specifically labeled 'extra-aged' or 'lactose-free'. |
| Aged Gouda | <0.2g | Excellent for sandwiches; choose longer-aged types for lowest lactose. |
| Swiss (Emmentaler) | <0.4g | Great for classic melts; be cautious with lower-quality deli slices that may contain added whey. |
| Provolone | 1–3g | A good option for many, but lactose levels can vary. Aged is better than young. |
| Colby | <1.0g | Some brands certify as lactose-free; generally a safe bet. |
| Mozzarella (Aged) | <1.0g | Aged low-moisture mozzarella contains less lactose than fresh mozzarella. |
| Processed American Cheese | Higher, varies | Often contains added whey, making it a poor choice for those with significant intolerance. |
Beyond Aged Cheese: Other Low-Lactose Options
For those who prefer a different flavor profile or have severe sensitivity, other options exist. Some companies specifically process cheese to be lactose-free by adding the enzyme lactase, which breaks down the milk sugar. These products will be explicitly labeled. Additionally, some individuals find that cheeses made from goat or sheep's milk, such as Feta (typically 0.1g per 100g) or Pecorino Romano, are easier to digest, though they still contain lactose.
Finally, for those who are highly sensitive or prefer not to consume any dairy, a variety of sliced, plant-based cheese alternatives made from nuts or other ingredients offer a true lactose-free experience.
Conclusion
For those wondering what sliced cheese has the least lactose, the answer lies in the age and processing method. Hard, aged varieties like sharp cheddar, Swiss, and Gouda are your safest and most flavorful bets, with Parmesan being a star performer. By understanding the role of aging and fermentation, and by checking for terms like 'aged' or 'lactose-free' on packaging, individuals with lactose intolerance can make informed choices and continue to enjoy sliced cheese on sandwiches, burgers, or as a snack without discomfort.
For additional resources and information on managing lactose intolerance, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) offers comprehensive guidance on dietary management and understanding the condition. NIDDK Lactose Intolerance Information
