Top 5 types of cheese that require a thermophilic starter culture
· Maryna Petruk · 7 min read
What is a thermophilic starter culture and why is it important for cheese production?
Thermophilic starter culture is a mixture of lactic acid bacteria that develop best at high temperatures (32-42°C). They:
- Promote milk coagulation: they produce lactic acid, which lowers the pH of the milk and helps form the curd.
- Shape flavour and aroma: different types of thermophilic bacteria give the cheese its characteristic flavour and aroma notes.
- Protect against harmful microflora: they create an unfavourable environment for the growth of pathogenic microorganisms.
Cheeses made with thermophilic starter cultures
Parmesan
An Italian classic, a hard cheese with a long ripening period. Streptococcus thermophilus and Lactobacillus delbrueckii subsp. Bulgaricus, are most often used to make Parmesan, and strains of Lactococcus lactis. are sometimes added.
Parmesan is considered the king of cheeses. It has a spicy, sharp-salty taste with hints of fruit and hazelnut, and a grainy structure. Its flavour develops new shades over time. Parmesan owes its beneficial properties not only to its composition but also to the maturing process.
Interestingly, in Italy there is a position of "Parma knocker", who checks the readiness of the cheese by tapping the cheese wheels with a silver hammer and judging by the sound whether it is ready.
It is the only product that people who are lactose intolerant can eat. Thanks to the work of the starter cultures throughout the production process, practically no lactose remains in the product.
Emmental
A Swiss cheese with large eyes. Thermophilic bacteria, combined with propionic acid bacteria, form its unique flavour and characteristic structure.
Why are thermophilic cultures important for Emmental?
- Characteristic "eyes": Thermophilic starter cultures used for cheeses with a high second cooking temperature release metabolites that stimulate the growth of propionic acid bacteria, which help form the characteristic eyes in Emmental. The high second cooking temperature combined with high acidity at the moment the cheese mass is pressed leads to the loss of lactose. During production the cheese is kept at high temperatures (22-25°C) for 6-8 weeks during secondary ripening.
- Flavour and aroma: Thermophilic cultures give Emmental its characteristic sweetish, spicy taste with almond notes.
- Texture: Delicate. Uniform, with large eyes.
The cultures used are Streptococcus thermophilus, Lactobacillus lactis, Lactobaciilus helveticus, Propionibacterium freudreichii sub-sp. Shermanii; some producers use Lactobacillus delbrueckii subsp. bulgaricus.
Gruyère
Made in Switzerland, it has a creamy yellow colour and a dense texture without holes. Gruyère has a creamy, sweetish taste with nutty tones, but mature varieties become saltier, sharper and earthier. This cheese is often confused with Emmental, but it differs in its smaller size, riper taste and small eyes.
Differences from other cheeses
- Features of the production process: Gruyère, like Emmental, is a cheese with a high second cooking temperature. Unlike Emmental, Gruyère has a pronounced flavour and aroma with an ammonia aftertaste. Secondary ripening (to form the pattern of the cheese), driven by the development of Propionibacterium freudreichii sub-sp. shermanii, lasts 2-3 months at 17-18°C.
- Long ripening period: Gruyère ripens for several months, and sometimes for more than a year (réserve). This allows the aroma and flavour to develop fully.
- Specific cultures: Special strains of thermophilic cultures are used to make Gruyère, selected to give the cheese exactly the characteristics that are expected.
The most commonly used cultures are Streptococcus thermophilus and Lactobacillus helveticus.
Cheddar
Cheddar is made in many countries. Traditional English, New Zealand, American and Canadian versions differ to some extent. The general difference from the technology of other cheeses is the cheddaring of the cheese mass, which creates the layered structure typical of this type of cheese. Subsequent milling of the cheese mass, salting, moulding and ripening help to produce a quality cheese. Thermophilic bacteria give it its characteristic tang and contribute to the development of complex aromas during ripening.
The most commonly used cultures are Lactobacillus lactis, Streptococcus thermophilus, Lactobacillus helveticus.
Incorrect use of thermophilic cultures can lead to the following production problems:
- Insufficient acidity: An insufficient amount of culture or unfavourable conditions can lead to insufficient acidity, which will adversely affect subsequent production processes.
- Off-flavours: Some strains of thermophilic cultures can give the cheese unpleasant bitter or metallic flavours.
- Slow milk coagulation: If the culture is inactive or insufficient, the coagulation of the milk may be prolonged.
Mozzarella
An Italian cheese used for pizza and other dishes. Thermophilic bacteria ensure rapid coagulation of the milk, subsequent cheddaring of the cheese mass and a soft, stretchy cheese. A starter culture for mozzarella most often includes the cultures Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus.
What defects can occur?
- Slow souring: May be related to low activity of the starter culture, low milk temperature or the presence of antibiotics.
- Excessive acidity: Occurs with an overdose of starter culture or prolonged cheddaring; as a result the finished cheese stretches poorly and breaks into short strands.
- Weak curd: May be caused by an insufficient amount of starter culture or poor milk quality.
- Bitter taste: May appear with excessive development of proteolytic bacteria.
- Unpleasant smell: May be related to the development of extraneous microflora.
Differences in the use of thermophilic cultures in different types of cheese
Parmesan, Emmental, Gruyère:
o Common features: similar thermophilic cultures are used to make these hard cheeses, ensuring their characteristic nutty flavour and dense texture.
o Differences: despite the similarity, the strains of thermophilic cultures may differ slightly, which affects the nuances of flavour and aroma of each variety. For example, Emmental is characterised by large holes, which are formed as a result of carbon dioxide released by certain types of bacteria.
Cheddar:
is also made using thermophilic cultures, but their composition may differ from the cultures used to produce Swiss cheeses. This is due to the specifics of the production process and the aim of obtaining a more pronounced sharp taste.
Mozzarella:
specific strains of thermophilic cultures are used to make mozzarella, ensuring rapid coagulation of the milk and a soft, stretchy cheese. These cultures also affect the acidity of mozzarella and its ability to melt.
How to choose the right starter culture for cheesemaking
The choice of thermophilic starter culture depends on several factors:
- Type of cheese: Each type of cheese has its own features that determine the choice of starter culture.
- Milk composition: The fat content, protein composition and acidity of the milk affect the choice of bacterial cultures.
- Production technology: Temperature regime, coagulation time, pressing and ripening – all these factors must be taken into account when choosing a starter culture.
- Desired flavour and texture: Different strains of thermophilic bacteria give the cheese different flavour and texture characteristics.
To its customers, Prodservis first of all recommends the French company BIOPROX, namely its starter cultures for cheese:
- DI-PROX MTRA, containing Lactococcus lactis, Lactococcus diacetylactis, Str.thermophilus.
- DI-PROX MTR – Lactococcus lactis, Str.thermophilus.
- DI-PROX TPC – Str.thermophilus, Lactobacillus delbrueckii subsp. bulgaricus.
- DI-PROX TPF – Str.thermophilus
Where to buy a thermophilic starter culture in Ukraine
You can buy a thermophilic starter culture for cheese in specialist shops for cheesemakers, as well as in online shops. When choosing a supplier, pay attention to the quality of the products, the company's reputation and the availability of certificates of conformity.
Conclusions: why thermophilic starter cultures are the key to quality cheese
Thermophilic starter cultures play a decisive role in cheese production. They affect the flavour, aroma, texture and shelf life of the finished product. The right choice and use of a thermophilic starter culture makes it possible to obtain a high-quality cheese that meets all consumer requirements.
Recommendations from the Prodservis dairy technologists:
- Before starting cheese production, it is advisable to consult specialists.
- Use only quality ingredients and equipment.
- Observe the temperature regime and the milk coagulation time.
- Regularly monitor the acidity of the cheese mass.
- Provide optimal conditions for the ripening of the cheese.
By following these recommendations, you will be able to make a tasty and wholesome cheese!
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