Fermented milk has been part of human history for a very long time and is a versatile product made in various regions around the world. By fermenting milk, the product is enhanced to be more beneficial than the original unfermented product. Some of the benefits of fermented milk include enhanced digestibility, as well as a higher nutritional value in the form of added probiotics, vitamins, minerals and amino acids. It also preserves products for a longer time, whereas unfermented and unprocessed milk usually has a very short shelf life.
Types of fermented products
Various types of cultured milk or dairy products are found across the globe, including fermented milk beverages, cheese, yogurt and different cultured dairy foods. According to Tetrapak’s Dairy Processing Handbook, milk products can be called cultured or fermented when they have been prepared using lactic acid bacteria fermentation (e.g. yoghurt) or a combination of this bacteria and yeast fermentation (e.g. kefir).
Lactic acid bacteria include strains such as Lactobacillus and Lactococcus. Here are a few examples of the world’s most popular fermented dairy products.
Each country has its speciality of soured milk. In South Africa buttermilk and maas, also known as amasi, are examples of fermented milk products. Buttermilk is commonly used in baking, while amasi is enjoyed as a nutritious beverage or served with a meal such as pap.
Crème fraiche is a well-known soured cream product from France and can be enjoyed on almost any meal imaginable, from soups to salads or even pizza.
Yogurt is a fermented food that retains the same level of protein and fat as the milk it is made from. It is a good source of calcium and vitamins B2, B6 and B12.
Kefir is an age-old fermented drink known for its health benefits. The word ‘kefir’ is derived from a Turkish word that means ‘good feeling’ and refers to one of the many benefits of this drink. Kefir is fermented using starter grains, known as kefir grains, which contain active micro-organisms in the form of lactic acid bacteria as well as yeast. Kefir is high in vitamins (B2, B12, D, K and A), minerals (phosphorus, magnesium and calcium), amino acids and enzymes.
Cheese is probably the most well-known fermented milk product. Both soft and hard cheese can be made from cultured milk. Fresh cheeses are made by straining the moisture out of sour cream or yogurt, while other types of cheese require culturing and fermentation.
Goat’s milk vs cow’s milk
The main difference between goat’s and cow’s milk is the type of protein it contains. Cow’s milk contains the milk protein alpha-s1 casein, which commonly causes allergies, whereas goat’s milk contains the easier to digest alpha-s2 casein. The fat molecules in goats’ milk are also smaller, making it easier to digest. Nutritionally, goat’s milk is higher in essential fatty acids, potassium and vitamins A, B3 and B6, while cow’s milk has high levels of vitamins B2, B9 (folate), B12 and selenium.
The higher levels of potassium in goat’s milk causes it to become alkaline in the body, whereas cow’s milk becomes acidic. Goat’s milk is also lower in lactose. However, goat’s milk has a much stronger taste than cow’s milk and might take a while to get accustomed to.
Fermenting cow’s milk can improve its digestibility, with kefir being a healthy option in this regard. Goat’s milk is also commonly used to make kefir and has the advantage of being naturally homogenised, which means that the cream will not separate during the kefir-making process.
How to make a kefir starter
To make kefir you need kefir grains. You can find it online or at most health shops, but you will need to buy extra as they will keep growing, which means you will be able to ferment multiple batches of kefir.
The equipment and ingredients needed to make a kefir starter are listed below. Note than non-metal items should be used because of the reactive nature of the acid found in kefir. You can use either goat’s or cow’s milk, but either should be ‘whole’ (full-cream) or as close to natural (organic full-cream) as possible.
- Glass jug.
- Paper towels or coffee filters.
- Rubber band.
- Non-metal slotted spoon.
- Cheese cloth.
- Non-metal bowl.
- Non-metal colander.
- Sealable glass jar for storing final product.
4 cups of full-cream milk.
1 tablespoon of kefir starter grains.
- It is essential to practice good hygiene when making fermented products, so make sure to clean all equipment and to wash your hands with soap before starting.
- Pour the four cups of whole milk into the jug. Add the tablespoon of grains and cover the jug with multiple layers of paper towels or paper coffee filters. Secure with a rubber band to protect it from environmental factors such as dust or unwanted microbes.
- To ferment, place the jug in a warm, dark spot (the temperature should be between 18 and 29°C). Leave it for approximately 24 hours. Once the milk has slightly thickened and has a slightly fermented smell, the kefir is ready.
- Strain the kefir by placing the non-metal bowl under a fine non-metal colander. Pour the kefir into the colander and stir with a plastic or wooden spoon to push all the kefir through. Only the grains should be left.
- To store your kefir, transfer it to the sealable glass jar. It can be kept in the fridge for approximately two weeks.
- To have a continuous supply of this elixir, start a new batch immediately after finishing your first. Rinse the glass jug thoroughly before adding the grains. Add 4 cups of milk to start the process again.
You can also make flavoured kefir by adding a quarter cup of fresh fruit, a tablespoon of cocoa powder, 1a quarter teaspoon of vanilla extract or one pitted date. – Ursula Human, AgriOrbit