There are hundreds of different cheeses, and their aromas (smells or tastes) are as varied as those in a colourful flower meadow. Aromatically relevant components in milk give the cheese its basic aroma, which is then altered and developed further as a result of microorganisms (bacteria, mould or yeast).
By increasing the fat content, adding extra salt and lengthening the ripening process, a more intense aroma is obtained.
In Emmentaler AOC, propionic acid is responsible for the typically sweet, nutty aroma.

In Emmentaler AOC, the holes are due to propionic acid bacteria. First of all, lactobacilli ferment the lactose into lactic acid amongst other things, just like in any other cheese. The propionic acid bacteria typically found in Emmentaler AOC then ferment the newly formed lactic acid into propionic acid, acetic acid and carbon dioxide (CO2), which is what makes the holes.
In Appenzeller® or Tilsiter for instance, heterofermentative lactobacilli ferment the lactose into lactic acid, ethanol, acetic acid and carbon dioxide. The lactobacilli can also ferment citric acid, which releases even more CO2.

Original Swiss Emmentaler cheese, which has been recognised as a controlled term of origin, or AOC, since December 2006, is produced from fresh raw milk using no milk treatment or additives. This means that the milk must come from cows that have not been fed silage. Raw milk must meet extremely strict quality requirements in order to be processed. Furthermore, Schweizer Emmentaler AOC must be produced by competent cheese specialists in commercial cheese dairies according to a traditional recipe. Foreign Emmentaler cheese with large holes is generally industrially produced and made from pasteurised milk.

All cheese was originally made using raw milk. However, nowadays many varieties of cheese are produced using pasteurised milk.
The raw milk used to make cheese such as Emmentaler AOC, Gruyère AOC, Sbrinz AOC and other cheese specialities is processed into cheese without undergoing heat treatment. As a result, the enzymes and bacteria inherently present in milk are still active in their natural environment. This becomes evident as the cheese matures because they produce aromas that do not exist in pasteurised cheese. Raw milk cheeses therefore become stronger with age.
When making cheese from pasteurised milk, the milk is heated to approx. 75°C and then cooled down again prior to cheesemaking. This inactivates the enzymes and bacteria inherently present in milk. Special aroma-forming substances (bacteria) are used to make the cheese mature. Cheese made from pasteurised milk is usually consumed when it is younger. It is also often milder tasting than raw milk cheese. Well-known varieties include Green Tilsiter, Mozzarella and most soft cheese.

Yes. Although some countries of exportation regularly query the hygienic safety of classic Swiss raw milk cheese varieties, i.e. Appenzeller, Berner Alp- and Hobelkäse AOC, Emmentaler AOC, L'Etivaz AOC, Le Gruyère AOC, Raclette Valaisanne, Raw Tilsiter (red), Tête de Moine AOC and Sbrinz AOC due to the use of raw milk, the scientific facts in no way 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. The cheese dough is properly acidified and undergoes a long maturing process that lasts between 3 and 18 months, all of which prevents pathogens from accumulating in dangerous quantities. Even sensitive consumer groups such as pregnant women can enjoy this type of cheese without hesitation.

Soft cheese made from raw milk is much more demanding as far as hygiene is concerned. 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 inactivated. Consequently, hygienic safety must be ensured by carrying out strict controls of milk quality right from the start and through continuous microbiological checks of production batches.

It is hard to tell from the outside whether cheese has been produced using conventional or organic methods (specified on cheese passports and labels on cheese wheels). Furthermore, there are several different labels signifying that agricultural products have been produced organically, the content of which remains similar (e.g. Bio Suisse bud, Migros-Bio, Demeter-International).
As far as cheesemaking is concerned, the recipe remains the same, except that no colouring may be added to the cheese smear. No use is made of genetically modified additives for producing Swiss cheese of any kind. However, there are major differences in terms of milk production. For instance, organic cows have more room in their stalls and, according to the law, may graze outside for a greater number of days than non-organic cows. No chemical fertilisers may be used for the production of roughage. When it comes to feeding, concentrated feed may only be used as a complement. Furthermore, tighter regulations exist for the medical treatment of sick cows.
Conclusion: milk production for organic cheese is gentler on the environment and on animals, thereby contributing to sustainable agriculture and healthy foodstuffs. However, as far as the taste and consistency of the cheese are concerned, there is hardly any difference.

Rennet is an enzyme that causes milk to curdle when present even in very small quantities. Also known as chymosin, it is taken from the stomach of young calves. Nowadays however, milk-curdling enzymes are also obtained microbially.
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 accumulate next to one another, 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. As well as 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 obtained from special mushroom stalks. They are GMO free and classed as kosher.
Vegetable rennet
Specific 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 for producing Swiss cheese. The decision not to use genetically manufactured rennet was made voluntarily under the cheese industry code, and is renewed every two years.

Specific lactic acid bacteria are used during the cheesemaking process. They turn the milk sugar (lactose) into lactic acid. At the same time, the pH-value drops. This is necessary to precipitate the casein and to produce cheese. The lowering of the pH-value also helps 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 split the protein and lactic acid into small, aroma-inducing substances. The young cheese that was formerly hard, compact and bland now becomes an aromatic foodstuff ready for consumption.

Yes, the smeary surface is an important part of many typical varieties of Swiss cheese such as Appenzeller®, Gruyère AOC, Tilsiter and Raclette. It forms because the cheese is rubbed with smear water (brine) 2-3 times a week and because of the relatively damp atmosphere (90-95%) and ideal temperature in the ripening ripening cellar (10-14 degrees Celsius).

The smear contains a great many microorganisms that play an important role in helping the cheese to mature, and therefore also in helping it to develop its aroma. At the start of the ripening 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, Mikrokokken and Arthrobacter for example, which are responsible for protein decomposition and coloration.

Silage milk contains a higher concentration of spores that could cause butyric acid fermentation in the cheese. Hard and semi-hard cheese that have been ripened for longer periods are particularly at risk. The traditional varieties of Swiss cheese such as Emmentaler AOC, Sbrinz AOC, Gruyère AOC, Tête de Moine AOC, Appenzeller®, Tête de Moine AOC, Raclette, Tilsiter and others are made exclusively from silage-free milk.

Unlike mould culture on white or blue mould cheese, mould growth is not desirable on Swiss cheese. It is recognisable by thin straight lines of mould growing on the surface. Some types of mould have a network that penetrates quite deep down inside the cheese. Since only a specialist can recognise whether mould is harmful or not, as a general rule, mouldy Swiss cheese should always be thrown away.