In coffee shops around the world, plant milks have never been so popular. In fact, according to Meticulous Market Research, the value of the global plant-based milk market is expected to be more than US $42.8 billion by 2029.

Within this market there are a range of plant milks – including soy, oat, almond, and coconut. As well as these options, there are an increasing number of barista-formulated plant milks which aim to replicate the creamier mouthfeel of cow’s milk.

However, despite the recent surge in popularity of dairy alternatives, some plant milks have been in use for centuries, namely soy milk, which can be traced back to 14th-century China.

It was during the 1990s that consumption of soy milk began to steadily increase, particularly in the US. But in the years since, soy milk has become less and less popular among consumers, as sales of other daily alternatives have skyrocketed – almond and oat milks in particular.

So, to learn more about why soy milk is less popular now, I spoke with two coffee industry professionals. Read on to find out what they had to say.

You may also like our article on plant milks & coffee: What does the future hold?

The emergence of soy milk

For many years, coffee shops around the world generally only served cow’s milk. However, this has changed dramatically in recent years – with many coffee shops across the globe now serving soy, oat, almond, and coconut milk, among other non-dairy options.

Although it has been consumed for centuries in some countries (mostly throughout Asia), soy milk started to become more popular in coffee shops during the 1990s. In fact, for many years, it was one of the very few plant-based options for people who didn’t consume dairy in both coffee shops and supermarkets. In some cases, soy milk was the only choice for these consumers.

Throughout the 1990s, a large number of commercial soy milks in coffee shops were heavily processed to mask their “beany” flavours that would often overpower the flavours of the coffee. However, because soy milk was often the only plant-based option in many coffee shops, sales naturally started to increase.

Moreover, in 1995, The New England Journal of Medicine published research which found evidence that higher levels of consumption of soy protein leads to lower levels of “bad” low-density lipoprotein (LDL) cholesterol and higher levels of “good” high-density lipoprotein (HDL) cholesterol. These health claims, among several others, led to a significant rise in soy milk consumption in the US throughout the late 1990s and early 2000s.

The rise of almond and oat milk

During the early 2010s, almond milk started to become much more prominent in coffee shops and supermarkets. Similar to soy milk, almond milk has been popular in some countries (particularly those in the Middle East) for centuries.

As almond milk grew in popularity, the consumption of soy milk started to steadily decline. Moreover, as the plant-based milk market began to diversify even further during the mid-to-late 2010s – notably with the emergence of oat milk – sales of soy milk continued to drop.

In 2018, according to Mintel, sales of almond milk accounted for around 64% of the US plant milk market, while soy milk only had around 13% of the market share in the same year. 

Panagiotis Konstantinopoulos is the Managing Director of Coffee Island, which operates more than 500 coffee shops in eight countries – including Greece, Canada, and the UK.

He tells me that across all of its locations, there has been a significant increase in demand for plant milks. He adds that in 2020, Coffee Island expanded its plant-based milk range from only soy to also include coconut, almond, and oat milks.

“The growth of dairy alternative milks has been significant, but our soy milk sales have dropped about 4%,” he says. Today, he adds that around 85% of milk-based beverages served at Coffee Island are made with cow’s milk, while 3.5% are made with coconut and almond, and only 1.5% are made using soy milk.

Furthermore, between 2018 and 2019, sales of oat milk skyrocketed from US $6 million to around US $40 million – largely thanks to brands like Oatly, Minor Figures, and Califia Farms. In several markets today, including the US and the UK, oat milk is by far the most popular plant milk option in coffee shops.

Why did soy milk become less popular?

It’s clear that soy milk consumption has fallen significantly since the 1990s, particularly in the US and the UK. Alongside the increasing diversification of the plant milk market, there are a number of other reasons for its decline.

One of the most prominent issues is a longstanding association between deforestation and soybean production. 

As a significant volume of global soybean production is used to feed livestock (including cows, pigs, chickens, and other animals), the volumes of soybean grown in Brazil, Argentina, and the US have steadily increased over the past few decades in proportion to population growth and meat consumption.

To keep up with growing demand, soybean monocropping has grown tremendously, which requires large amounts of land to be cleared. Ultimately, this can lead to higher levels of deforestation.

Growing concerns over rising deforestation rates, particularly in Brazil, led some soybean producers and traders to take action. In fact, in 2006, Brazil instated a Soy Moratorium (SoyM), a voluntary zero-deforestation agreement which meant signees could not source soybean which was grown on deforested land in the Amazon.

Although the moratorium was renewed indefinitely in 2016, soybean production continues to be linked to deforestation in the Amazon rainforest. For example, in 2018, a report claimed that Brazilian soybean production was linked to some 200 square miles of deforestation, according to the United States Department of Agriculture.

Deiverson Migliatti is the founder of Sterna Café, a coffee chain in Brazil.

“It is inevitable that coffee shop owners and consumers alike look for more sustainable milk options,” he says. He adds that in 2015, the company made the decision to replace soy milk with oat milk across all of its locations.

However, it’s also important to note that soy milk production only represents a small percentage of all soybeans cultivated around the world. It’s estimated that around 6% of global soy-based products are made for human consumption, with the remaining 94% developed for livestock feed.

Moreover, soybean production is considerably more environmentally friendly than the production of cow’s milk, especially when it is intercropped and grown more sustainably. For instance, cattle are estimated to contribute to around 11% of all global greenhouse gas emissions produced by human activity.

To add to this, the production of soy milk is not as water-intensive to grow when compared to other popular dairy alternatives – most notably almond milk. To produce a single glass of almond milk, it’s estimated that around 74 litres of water are required, whereas for one glass of soy milk you would require around five litres of water.

Health concerns

Despite the existence of research which supports soy milk’s health benefits, there have been several studies in recent years which also raise concerns.

“Some of our consumers are cautious about drinking soy milk, mostly because of claims that consuming genetically-modified soy products can increase the number of soy isoflavones in your diet,” Panagiotis tells me. 

As they are a type of phytoestrogen, soy isoflavones have been found to be genetically similar to the female hormone oestrogen. Some studies have found that higher levels of soy isoflavone consumption can potentially lead to developing or exacerbating several health issues, such as a higher risk of developing breast cancer and heart disease in both men and women.

However, there is plenty of conflicting evidence to dispute these scientific findings. Several studies have concluded that phytoestrogens in soy milk could even reduce the risk of developing a variety of cancers and chronic health conditions, including a smaller chance of developing breast cancer in women.

In fact, soy milk is one of the most nutrient-dense plant milks, containing high-quality fats and proteins, as well as various amino acids, vitamins, and minerals.

Other research has found that the high levels of processing in soy milk production is predominantly responsible for changing the healthy connotations of soy consumption. The continuous soaking and reheating of soybeans during production can mean a loss of isoflavones, especially at higher temperatures.

Ultimately, more scientific support is needed for any discussion about how healthy or unhealthy soy milk might be.

What might the future hold?

As the number of plant-based milk options continues to grow in coffee shops around the world, one question remains: can soy milk still retain its market share?

“The taste of soy milk can overpower the flavours of the coffee,” Deiverson says. “[Oat milk has become much more popular because] of its more neutral flavours and good performance when steaming and pouring latte art with it.”

Many consumers and specialty coffee professionals alike claim that oat milk’s neutral flavours, creamier texture, and better foamability make it a more suitable choice for milk-based coffee beverages, as opposed to other non-dairy milks like soy and almond.

The arguably more superior texture and steaming performance of oat milk have made it vastly popular in coffee shops in recent years – including in the Asia-Pacific market. In fact, a 2021 survey conducted by World Coffee Portal found that oat milk is the most popular plant milk in UK coffee shops, while sales of soy milk beverages dropped by 0.5% during the same period.

However, despite clear preferences for oat milk, other consumer studies have found that soy milk and other plant milks are rated similarly during blind tastings.

Panagiotis believes that both soy and oat milks have similar neutral flavours when paired with coffee, whereas almond and coconut options can be more overpowering. He adds that Coffee Island uses a barista-formulated soy milk that can produce high-quality and stable microfoam.

“Nowadays, oat milk is quickly becoming the most popular plant milk, especially compared to soy and almond,” he tells me. “However, in a few years, we could see more plant-based options on the market – including pea, potato, cashew, pistachio, pecan, rice, and help milks.”

We’ve already seen the plant milk market diversify significantly, with more options available than ever before – including plant milk blends containing several base ingredients, such as oat, soy, and sunflower seed.

Many of these blends have been developed to closely mimic the texture and creaminess of cow’s milk – a trend that is seemingly becoming more popular.

As oat milk continues to grow and seems poised to dominate the plant milk market, soy milk’s future in specialty coffee and beyond seems uncertain. While it is still popular in certain parts of the world, its market share is clearly falling on a global scale.

It’s important to acknowledge that soy milk arguably paved the way for more non-dairy alternatives in coffee shops and beyond, but whether or not it will experience a resurgence is certainly something worth keeping an eye on.

For now, one thing remains clear: sales of soy milk beverages on the whole are on a downward trajectory, and there seem to be no signs that this will reverse any time soon.

Enjoyed this? Then read our article on a coffee shop favourite: Why is oat milk so popular?

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