All cheese? Fascinating questions and answers

Silage milk has a higher content of spores, which can cause late-blowing in the cheese. This affects hard and semi-hard cheese with a long maturation period in particular.

Traditional Swiss cheese varieties like Emmentaler AOP, Sbrinz AOP, Gruyère AOP, Appenzeller®, Tête de Moine AOP, Raclette, Tilsiter and others are only made from silage-free milk.

There are hundreds of different types of cheese and their flavours and aromas are as diverse as those found in a colourful floral meadow. It is the flavour components in the milk that produce the basic flavour. Microorganisms (e.g. bacteria, mould, yeast) then change and develop this flavour.

The flavour is intensified by increasing the fat content and adding salt, and by leaving the cheese to mature for longer.

No. The cheeses made for domestic use and for export are identical. In both cases, mild, younger cheeses and more mature specialities with a stronger aroma are available. Taller, more curved wheels are produced for Italy – the most important export market for Emmentaler AOP.

In the case of Emmentaler AOP, the holes are caused by propionic acid bacteria. First of all, lactic acid bacteria ferment the milk sugar into lactic acid (amongst other things), as is the case in other cheeses too. The propionic acid bacteria typical of Emmentaler AOP then ferment the newly formed lactic acid into propionic acid, acetic acid and carbon dioxide (CO2), which in turn forms the holes.

When it comes to Appenzeller® or Tilsiter for example, it is heterofermentative lactic acid bacteria, which ferment the milk sugar into lactic acid, ethanol, acetic acid and carbon dioxide. They can also ferment citric acid and, in doing so, can release even more CO2.

If you remove the water content from cheese, you are left with fat, protein, lactic acid, vitamins and minerals – in other words, the dry matter. You can use this dry matter to calculate the fat percentage.

When shopping, you can use the fat in dry matter to ascertain the level of fat in the Swiss cheese and can gauge an idea of the flavour: the higher the fat content the smoother, finer and creamier the Swiss cheese.

The fat levels are as follows:

• Double cream cheese: min. 65% FDM
• Cream cheese: min. 55% FDM
• Full-fat cheese: min. 45% FDM
• Three-quarter-fat cheese:  min. 35% FDM
• Half-fat cheese: min. 25% FDM
• Quarter-fat cheese: min. 15% FDM
• Low-fat cheese: less than 15% FDM

Cheese was originally produced using raw milk. But nowadays, many cheese varieties are made using pasteurised milk.

The milk used to make raw milk cheese, such as Emmentaler AOP, Gruyère AOP, Sbrinz AOP and other cheese specialities, is turned into cheese without being heated first. As such, the enzymes in the milk and the bacteria from the natural environment remain active. This is noticeable as the cheese matures, as they produce aromas, which are not present in pasteurised cheese. The flavour of raw milk cheese gets stronger as it ages.

In the case of cheese that is made using pasteurised milk, the milk is heated to at least 72 °C (for
15 seconds) and then cooled down again, prior to it being used to make cheese. This process serves to deactivate the enzymes in the milk and the naturally occurring bacteria. Special aroma-forming substances (bacteria) are used to make the cheese mature. Cheese made using pasteurised milk is usually consumed when it is younger and tends to be milder than raw milk cheese. Well-known varieties include Green Tilsiter, mozzarella and most soft cheese.

Yes. Although some export countries regularly query the hygienic safety of classic Swiss raw milk cheese varieties – i.e. Appenzeller®, Berner Alpkäse and Hobelkäse AOP, Emmentaler AOP, L'Etivaz AOP, Le Gruyère AOP, Raclette Valaisanne AOP, Raw Tilsiter (red), Tête de Moine AOP and Sbrinz AOP – due to the use of raw milk, the scientific facts do not support this view. The milk used is of excellent quality, it is processed quickly i.e. within 18 hours of milking, and it is heated to relatively high temperatures. This is combined with the fact that the cheese is properly acidified and undergoes a long maturation process that lasts between three and 18 months. All of these steps help to prevent pathogens from accumulating in dangerous quantities. Even sensitive consumer groups, such as pregnant women, can enjoy these cheeses without issue.

Soft cheese made using raw milk is much more demanding in terms of hygiene. Given that the cheese mass is hardly heated at all, the water content is high and the ripening process only takes a few weeks, there can be no guarantee that the pathogens present in the milk have been deactivated. As a result, hygienic safety must be ensured through stringent checks on the quality of the milk from the moment it is sourced and the continuous microbiological checks of production batches.

It is hard to tell whether a cheese has been produced conventionally or using organic methods from looks alone (specified on labels on cheese wheels and on cheese passports). There are also several different labels for the organic production of agricultural products, which have similar properties (e.g. Knospe, Migros-Bio, Demeter-International).

In terms of cheese production, the recipe is the same. The only difference is that no colouring can be used in the cheese smear. Genetically modified additives are not permitted for use in the production of cheeses from Switzerland. When it comes to milk production, however, there are great differences. Organic cows have more space in their stalls and, according to law, may graze outside for a greater number of days than non-organic cows of the same species. No chemical fertilisers may be used for the production of roughage. When it comes to feeding, concentrated feed may only be used as a dietary supplement. Furthermore, the regulations concerning the medical treatment of sick cows are stricter for organic cattle.

Conclusion: milk production for organic cheese is more gentle on the environment and on the animals. As such, it contributes to sustainable agriculture and to the production of healthy food. When it comes to taste and quality, there is very little difference.

Rennet is an enzyme that causes milk to curdle when present even in very small quantities. It is also known as chymosin and is taken from the stomachs of young calves. Nowadays, milk-curdling enzymes are also obtained microbially, however.

Caseins (protein) are microscopic components of milk that occur as micelles within milk. Casein micelles have a negative charge, which means that they repel one another and are spread evenly throughout the milk. When rennet is added, the casein micelles lose their negative charge and group together, forming a kind of structure. The milk coagulates. This is due to the dissociation of a protein fragment with a high negative charge from the casein micelles, removing the negative charge from the casein.

Calf stomach rennet

Original rennet is produced from the fourth stomach chamber of calves that have been raised on milk. In addition to the careful selection of raw materials, production of this excellent product requires precise processing methods and controls. This is because the chymosin in calf stomach rennet is the only type of chymosin that has been specifically designed by nature for souring cow’s milk. The calf stomachs come from BSE-free countries. The rennet is guaranteed GMO-free.

Microbial rennet substitutes

Microbial rennet substitutes are sourced from special mushroom stalks. They are GMO-free and kosher.

Vegetable rennet

Certain plants, such as stinging nettles or green figs, release the enzyme pepsin. This coagulating enzyme is mainly used in certain cream cheese specialities. It is not suitable for producing hard cheese.

Genetically engineered rennet

This type of rennet, obtained from genetically modified strains of bacteria, is not used to produce Swiss cheese. The decision not to use genetically manufactured rennet was made voluntarily under the cheese industry code, and is renewed every two years.

*GMO = genetically modified organisms

Specific lactic acid bacteria are used during the cheesemaking process. They convert the milk sugar (lactose) into lactic acid. This also causes the pH-value to fall, which is necessary to precipitate the casein and to produce cheese. The lowering of the pH-value also helps to prevent the growth of undesired, pathogenic germs.

It is the lactic acid bacteria which cause the cheese to ferment and mature. The bacteria produce a variety of enzymes that break down the protein and lactic acid into small, aroma-inducing substances. The hard, compact and bland, young cheese becomes an aromatic foodstuff ready for consumption.

No, the smear on the surface is a key component of many typical Swiss cheese varieties, including Appenzeller®, Gruyère AOP, Tilsiter, Raclette. It is created as a result of the cheese being rubbed with smear water (brine) two to three times a week and because the ripening cellar has an ideal temperature of 10-14 degrees Celsius and an ideal humidity of 90-95%.

The smear contains lots of microorganisms, which play a key role in helping the cheese to mature and, therefore, also help it to develop its aroma. At the start of the maturation process, it is mainly yeast (Debarycomyces hansenii) that can be found, deacidifying the surface of the cheese. This is when other microorganisms really start to proliferate, such as Brevibacterium linens, Micrococcaceae and Arthrobacter for example, which are responsible for protein decomposition and colouration.

It is important to differentiate between a cheese that is supposed to have mould and a cheese that is mouldy because the product has been stored incorrectly or it is past its use-by date.

Mould on white and blue-veined cheese and other types of cheese is desired and is typical for these speciality cheeses.

In the case of hard cheese, mould can form on the surface of the cheese. If mould appears on the surface of cheese, it is advisable to cut off the cheese containing the mould.

In the case of cream cheese and soft cheeses, the undesired mould quickly penetrates the centre of the cheese. These products need to be thrown away.

Late-blowing is the process in which the lactic acid in cheese is fermented into butyric acid, carbon dioxide and hydrogen. Butyric acid has an unpleasant smell. Carbon dioxide and hydrogen cause the cheese to swell up. In order to avoid late-blowing, the spores can be physically removed from the milk – either through bactofugation or through filtration.

Additives can also be added to prevent the spores from germinating (e.g. nitrate and lysozyme. These additives are not used in Switzerland. Or you can use silage-free milk. Late-blowing can also occur in cheeses made using pasteurised milk, as the spores are heat-resistant and are, therefore, not killed by the pasteurisation process.