In principle, you can use any animal milk. When purchasing, please look for homogenised and pasteurised milk, as this is more suitable for yoghurt preparation. Cow's and sheep's milk are ideal, goat's milk is always more fluid because αs1-casein, which is so important for water binding and thus the formation of casein micelles, is only present in small quantities.
For hygienic and health reasons, raw milk should be heated once to 85 °C before yoghurt preparation.
When using a milk alternative, it should be noted that the addition of thickeners may be necessary. The lactic acid bacteria Streptococcus thermophilus and Lactobacillus acidophilus can convert the sugar in the plant-based drink, so fermentation is successful. However, the consistency of the ‘veggieghurt’ is very runny because the protein content is generally very low and the ideal protein, which binds a lot of water and can therefore form the micelles, is completely absent.