Plant-based alternatives may not be labelled as ‘yoghurt’; this is prohibited by EU Regulation (EEC) No. 1898/87 because yoghurt is defined as a dairy product (udder product) and plant-based drinks of all kinds are not dairy products.
The lactic acid bacteria Streptococcus thermophilus and Lactobacillus acidophilus can convert the sugar in the soya drink, so fermentation is successful. However, the consistency of ‘soyaghurt’ is very liquid 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 missing. Industrially, ‘soyaghurt’ is therefore provided with all kinds of additives (thickeners, sugar, stabilisers, etc.), but ultimately it has nothing to do with real yoghurt.