Only one of the drinks in the photo above is milk. Can you spot which one? The answer is the one in the middle. The rest are different plant-based drinks and you’ll notice they all have something in common – a light colour. The desire to imitate the colour of milk explains why producers of plant-based drinks choose direct UHT rather than indirect UHT (ultra-high temperature or ultra-heat treatment).
Dairy milk vs plant-based beverage
Milk is milk and will always have a special position in consumers’ minds and hearts. There’s nothing quite like it, or is there?
Many plant-based beverages were originally introduced as an alternative to dairy milk and used milk as a benchmark. Their popularity is growing fast but milk still dominates traditional markets. In the US, for example, plant-based beverages accounted for 16% of all dollar sales of retail milk in 20211.
1. Source: SPINS categories as refined by The Good Food Institute, Inc., USA, 2021
Tastes differ
On the question of taste, consumers seem to be split down the middle. In one market research survey2 conducted in the US, the top reason for replacing dairy beverages with plant-based was a better taste according to 47% of the respondents.
According to another survey3 from 2020, 43% of consumers that reject plant-based beverages do so because of disliking the taste.
2. Mintel Report on Non-Dairy Milk, USA, Apr 2016.
3. Ipsos quantitative research, 2020.
Three generations
Though soya beans have been made into a traditional drink in China for at least 2,000 years, it is only since the 1970s that the industrial processing of soya beans gave a drink with a taste and consistency more closely resembling dairy milk. Soya drink represents the first generation of plant-based beverages in modern industrial times. The soya-based segment still dominates today with the largest revenue share of the global plant-based beverages market. But other plant-based alternatives have come along to compete. The second generation includes nuts such as almonds and cashews as well as coconut ‘milk’ and other milk substitutes from grains, rice and oats. Regarding oats, many markets were opened for up oat drinks by the pioneer Oatly first launched in the late 1990s in Sweden.
Soon the third generation of plant-based will be here using new ingredients from legumes and seeds. Drinks based on peas are already starting to appear on supermarket shelves in certain markets. The use of bambara nuts, hemp seeds and flax seeds could be next. Hemp seeds are not only highly nutritious, but they have the advantage of producing a drink with a pure white colour. That’s the look consumers weaned on cow’s milk seem to prefer.
Colour is critical
Whatever the plant source, colour remains a vital ingredient for success. The challenge for producers is that browning or discoloration tends to occur if too much heat is applied during processing. For this reason, the heat load needs to be kept to a minimum during UHT treatment. And that’s why the plant-based drinks sector is dominated by direct UHT, a form of heat treatment that is as gentle as possible on the product while still achieving commercial sterilization for a prolonged shelf life.
Direct vs indirect
The difference between direct UHT and indirect UHT can be summed up by the graph shown here. From the 80°C starting point in both cases, indirect UHT has a slower climb up to the ultra-high temperature with a longer decline. With direct heating, you instantly heat to the ultra-high temperature with a short holding time and then use flash cooling. In contrast, heating and cooling in indirect UHT take much longer with a higher overall heat load. Therefore the risk of affecting the colour, taste and impairing the delicate quality of plant-based drinks increases with indirect UHT. Plant-based products are more sensitive to colour change compared to milk, so more heat means more colour change.
A direct UHT unit can be used for a variety of different plant-based drinks as the treatment in the injector is basically the same. The same unit can also be used for the treatment of milk where the relatively low heat load helps to preserve milk’s original qualities such as taste and nutrition, while still removing unwanted pathogens. This is the kind of flexibility direct UHT technology is renowned for and there are many ways to customize a line for a particular customer’s needs.
UHT from the start
Traditionally, milk has been kept refrigerated in a cold chain all the way from milking the cow to drinking at home. Later, UHT treatments have opened up the possibility of selling long life milk without the need for refrigeration.
In contrast, right from the time of the first generation of plant-based beverages, the preferred method of treatment has been UHT enabling a long shelf life at ambient temperatures.
These drinks may not be exactly comparable to milk in terms of nutritional quality and taste, but in one key aspect, they are comparable — colour. And their original light colour is preserved thanks to the gentle treatment of direct UHT.
