December 22, 2022

Should we weigh milk in coffee shops?


In the vast majority of specialty coffee shops around the world, dosing coffee is an everyday practice for preparing both espresso and filter beverages. When baristas weigh their doses, they ensure that they are using an optimal coffee-water ratio, thereby extracting the full range of a coffee’s flavours and aromas.

However, in his winning 2022 World Barista Championship (WBC) routine, Australian competitor Anthony Douglas also weighed his milk course beverages to create a more consistent sensory experience for all four WBC judges.

Naturally, this has led to a pertinent question being asked in the specialty coffee sector: should more coffee shops also be weighing milk? And if so, how would this influence both barista workflow and the customer experience?

To find out more about weighing milk in coffee shops, I spoke with several coffee professionals. Read on for more of their insight.

You may also like our article on whether we should allow plant milks in the World Barista Championships.

a cup of coffee with latte art being measured on a scale

Why weigh milk?

First and foremost, weighing milk-based beverages can help to reduce milk waste, which is particularly useful for coffee shops. Most baristas are trained to carefully eyeball the amount of milk they pour for each drink, but even the most experienced baristas can sometimes use too much.

Of course, this leads to leftover steamed milk, which if not used for other beverages, can quickly increase a coffee shop’s waste costs. In fact, some coffee shops can waste up to US $15 of leftover milk every day.

Anthony Douglas is the training manager at Axil Coffee Roasters in Melbourne, Australia. He is also the 2022 World Barista Champion.

During his winning WBC routine, Anthony prepared his milk course beverages for the judges before weighing each drink on a scale. But why did he do this?

“Baristas and WBC competitors weigh coffee doses and yields, so also weighing your milk can add another level of consistency – especially in competitions,” he says.

Kirk Pearson is the founder of Sub-Zero Coffee, a frozen coffee pop-up shop in Victoria, Australia. 

He emphasises that much like using an optimal coffee-water ratio, baristas and coffee shop owners should do the same with coffee and milk.

“A few years ago, we were using an espresso blend from ONA Coffee,” he says. “[After some experimenting], we found it tasted best with 110g of milk – no less and no more.

“It’s a great example of how weighing milk is so important,” he adds.

Most different kinds of milk (including cow’s milk and certain types of plant milks) taste sweet and have a creamy mouthfeel. In some cases, using too much milk can overpower the delicate and complex flavours in coffee – although this very much depends on the coffee you use. For instance, preparing a Gesha as a milk-based beverage could minimise the more delicate floral flavour notes.

Angus Mackie is a barista trainer at ONA Coffee and the creator of Nucleus Coffee Tool’s Compass. 

“Milk-based coffee beverages shouldn’t be considered any less important than black coffee,” he tells me. “Different amounts of milk can result in different sensory experiences when drinking a milk-based beverage, as different volumes and textures of milk can change the sweetness of a drink.”

Angus explains that after he was diagnosed with tongue cancer a few years ago, more than half of his tongue was surgically removed – leading to significant damage to his taste receptors. He says that while he was training to regain more of his palate back, milk-based beverages were particularly useful for identifying certain flavour notes and aromas.

“Moreover, weighing milk is a useful practice when training baristas to improve their milk steaming and pouring skills, as well as their palates,” he adds.

a barista pours steamed milk into a cup of coffee

Should more coffee shops be weighing milk?

Considering the various benefits that we’ve just listed, should more coffee shops start weighing milk?

“In Melbourne specifically, around 80% of drinks served in coffee shops are milk-based – typically flat whites and lattes,” Anthony explains. 

However, Kirk tells me that weighing milk is not a common practice in the country.

“Only around 5% of Australian coffee shops weigh milk, but I would love to see more of them doing it,” he says. 

He emphasises that weighing milk for each milk-based beverage is often not practical for many baristas, which could be the reason for low uptake. However, he adds that automated milk steaming and foaming systems could help to improve barista workflow if weighing milk is something they want to start doing.

“Some coffee shops, like Axil and ONA, use automatic milk foaming systems like Übermilk,” he says. “Although it may not be realistic to weigh milk for every beverage, automated systems can dispense predetermined amounts of milk.”

Hany Ezzat is a Sales and Guest Roaster Manager at ONA Coffee. He explains that the practice of weighing milk is more common in specialty coffee shops which serve more exclusive and high-end coffees.

“Coffee shops are more likely to weigh milk if they’re using single origin coffee roasted for espresso, or if they’re serving a reserve coffee,” he says. “If a customer is paying a more premium price then they should receive a more premium service, which includes baristas being more accurate and precise with coffee to milk ratios.”

Anthony agrees, saying: “Weighing milk helps to ensure consistency, as well as training baristas to understand how different amounts of microfoam affect milk-based beverages.”

The Flight Coffee Hangar is a cafe serving house-brewed coffee, sandwiches

Considering the impact on baristas and consumers

Although weighing milk-based beverages could significantly slow down workflow during busy rushes, baristas could instead carry out this practice during quieter periods. This way, they have more time to focus on how they need to steam the milk to reach the required weight.

Overall, Hany believes that weighing milk is advantageous for baristas.

“It’s a positive thing,” he says. “It allows them to understand more about how to prepare and serve high-quality beverages.

“Personally, I teach the baristas I work with that they should texture milk to one consistency so that every milk-based drink has between 0.75cm and 1cm of microfoam,” he adds. 

Hany explains that in his experience, preparing milk-based beverages (mainly of a similar size, such as cappuccino and a flat white) to a more consistent texture and weight means showing the full spectrum of each coffee’s flavours.

“For instance, a roaster may develop a roast profile so that when extracted as espresso, the coffee can be paired with around 120g of milk,” he tells me. “This means that baristas should steam the milk [with a target weight in mind].

“Milk with more microfoam will weigh less than milk with less foam,” he adds. “The amount of microfoam will also have a big impact on beverage texture.

“You can weigh 120g of milk for a 6oz (170ml) drink, but if the milk isn’t textured correctly, it can negatively affect the consumer experience,” Hany continues.

Ultimately, if the coffee to milk ratio is too overpowering, or the milk texture isn’t smooth enough, consumers could receive a lower-quality beverage. However, for the most part, if baristas are trained to steam and pour milk well, the majority of consumers will receive high-quality milk-based drinks.

world barista champion anthony douglas performs his routine in melbourne

Will we see this practice more in coffee shops and competitions over the next few years?

In general, all of the coffee professionals I spoke with believe that Anthony’s winning WBC performance will lead to more coffee shops – as well as other WBC competitors – weighing their milk-based beverages.

“Throughout the years, WBC competitors are starting to control more and more variables,” Anthony says. “I definitely see consistency in the weight of milk becoming more prominent moving forward.

“Although two different types of steamed milk may reach the same level in a cup, they could have completely different textures,” he adds. “If you weigh the beverage after you have poured the milk, however, it’s a useful indicator as to how much foam you have created.”

He tells me how weighing milk helped him to develop the milk course section of his 2022 WBC routine.

“I trained a lot using the same amount of milk and the same workflow,” he says. “The difference between each beverage I weighed was roughly 0.2g.”

Competitions like the WBC assess a variety of technical barista skills, including precision, accuracy, and consistency. In theory, this means serving more consistent drinks to competition judges – whether in weight, flavour, appearance, or any other factor – could lead to higher overall scores.

However, despite indications that the practice of weighing milk could become common, Angus believes it could take some time for coffee shops to start adopting it.

“Milk-based beverage tasting workshops could be a useful tool,” he says. “Many coffee shops hold black coffee cupping sessions, but milk-based beverages can have a different range of sensory experiences [for both baristas and consumers]. 

“Adding milk to coffee can emphasise different levels of sweetness,” he adds. 

In order to assist baristas to understand more about weighing milk-based beverages, Angus suggests a training exercise:

  1. Prepare two milk-based drinks using the same espresso recipe and steam two jugs of milk to the same texture.
  2. Pour each beverage, but with a 10g weight difference. Taste to compare how different weights affect the beverage.
  3. Then, prepare two-milk based drinks using the same espresso recipe, but steam two jugs of milk to different textures.
  4. Pour the same weight of milk in each drink. Taste to compare how different textures affect the beverage.
Barista Hide Kono from New Zealand participates in the World Barista Championship in Bogota June 3, 2011. Every participant is required to serve each of four sensory judges a single espresso, a single cappuccino and a single signature beverage of their choice

Although it may not be suitable for every coffee shop, there are clear benefits to weighing milk-based drinks for baristas, café owners, and consumers alike. Not only can waste be reduced, but overall beverage quality could also increase – an important consideration for WBC competitors, too.

However, whether or not we will see more coffee shops weighing milk-based beverages in the coming years remains to be seen. But with more and more coffee shops implementing automated milk foaming solutions into their businesses, it could become easier for baristas to start weighing their milk while also maintaining a good workflow.

Enjoyed this? Then read our guide to working with plant milks.

Photo credits: Hany Ezzat, World Coffee Events

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