Milk is an important part of modern diets. As awareness of food safety grows, more attention is being paid to how milk is heat-treated and processed. The treatment temperature also affects the quality of milk kefir, so choosing the right brand matters when you want good-tasting kefir.

1. Fresh Milk

Fresh milk is the best choice for making milk kefir. It undergoes less processing than milk powder or long-life milk, so more of its nutrients remain intact. The probiotics and yeasts in kefir grains need these nutrients; well-fed grains can make the best product for you. Milk powder and long-life milk undergo more complex processing, which reduces some of these nutrients and generally produces less flavorful kefir.

Whole milk is also considered better than skim milk. It contains more fat-soluble vitamins, including vitamins A, D and E, as well as more fatty acids. These nutrients keep the probiotics in the grains active and help improve the kefir’s taste and texture. Most of the fat has been removed from skim milk, so it cannot provide the same nutrients.

Fresh-milk brands and heat treatment

Brands use different heat-treatment methods. The four main methods differ in temperature and treatment time.

1. Ultra-high-temperature treatment (UHT)
Temperature: 125–135°C
Time: 2–3 seconds
This is the most common method in Taiwan. It kills most bacteria in raw milk, reducing spoilage caused by temperature changes during transport and keeping quality more consistent. However, rapid heating denatures milk proteins, making them harder to digest and absorb. Kefir grains do not favor these denatured proteins either, which can lead to unsuccessful fermentation, such as kefir that does not thicken. Long-life milk uses this method too, at a higher temperature and for longer. We therefore do not recommend this type of fresh milk.
Brands: Wei Chuan, Uni-President, Kuang Chuan, Lin Feng Ying and Kirkland.

2. Gentler high-temperature, short-time treatment
Temperature: 80–90°C
Time: More than 15 seconds
Because this treatment is less intense than UHT, some of the fresh milk’s nutrients and calcium remain. If the milk stays above 7°C for too long after treatment, its quality can change and it may form clumps. Refrigerate it promptly after bringing it home and use it as soon as possible.
❤ We have used I-MEI whole milk for a long time and find that it gives the best fermentation results. ❤
Brands: I-MEI (義美), Sifang (四方) and Chulu (初鹿) fresh milk.

3. High-temperature, short-time treatment (HTST)
Temperature: 72–75°C
Time: 10–15 seconds
This method retains the nutrients in raw milk.
Brand: Uni-President Ruisui Jizhi fresh milk (統一瑞穗極制鮮乳).

4. Low-temperature, long-time treatment (LTLT)
Temperature: 62–65°C
Time: 30 minutes
The lower temperature preserves more of the milk’s nutrients, including whey protein and vitamins. However, the longer treatment time makes large-scale production difficult. Shelf life is shorter and prices are generally higher.
Brands: Xiuguluan 65°C fresh milk (65℃秀姑巒鮮乳) and Lao Die fresh milk (老爹鮮乳).

2. Milk Powder and Long-Life Milk

Although milk powder and long-life milk can be used to make kefir, we do not recommend them. Most milk powders undergo extensive processing and lack the lactose the grains prefer, resulting in poorer flavor, texture and even nutritional value. If you still decide to use milk powder, choose a minimally processed brand containing at least 12 grams of lactose. Fresh milk remains the best choice for making milk kefir.

3. Plant-Based Milk

Plant-based milks can also be used to ferment kefir, including soy milk, almond milk, coconut milk and rice milk.

Plant-based kefir can be enjoyed by people with lactose intolerance and vegetarians. However, kefir grains still need regular contact with and nourishment from the lactose in dairy milk to survive. After every six batches with plant-based milk, make one batch with dairy milk to replenish their lactose supply. If you are strictly vegan or have a severe milk allergy, consult your doctor. Plant-based milks also have different nutrient compositions from dairy milk, so the taste and texture will differ.