The second-best-selling option is almond milk, with consumers spending £105 million on the plant-based alternative in 2020, compared to £96 million in 2019.
The survey of 2,000 people aged 16 and over, found that in those aged between 25 to 44, almost 44 per cent are plant-based milk consumers.
The main motivations for drinking plant-based alternatives were cited as concerns about the environment and health.
More than 50 per cent of those surveyed said they think their choice of milk could make a difference to the environment, while 23 per cent said they believe plant-based milk is better for their health.
Amy Price, a senior food and drink analyst at Mintel, said the growth of plant-based milk sales suggest it is becoming a mainstream option.
“The plant-based trend continues to gain momentum in the UK, fuelled by environmental and health considerations.
“Almost a third of adults drink plant-based milk, evidence of its firmly mainstream status and appeal far beyond the vegan or vegetarian populations.”
She said young people’s preference for plant-based milk could drive down the usage of cow’s milk over time.
“While almost ninety per cent of Brits use cow’s milk, usage continues to be lower amongst younger Brits than older age groups, as it faces intense competition from plant-based varieties.
“If they retain their plant-based milk habit as they age, this stands to drive usage across the population upwards over time, fuelling long-term growth for the plant-based milk category,” she said.
This shift in preferences towards plant-based milk could also be credited to the Covid-19 pandemic.
More than a quarter of those polled (26 per cent) agreed that the coronavirus outbreak made plant-based food more appealing to them.
However, cow’s milk still remains the biggest market, with sales of the milk reaching £3.2 billion in 2020.
The number of people who prefer cow’s milk increased with each age group. In those aged 65 and over, 96 per cent of those surveyed drink standard cow’s milk.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies