I’m a food scientist — here’s why Coke tastes better at McDonald’s

Why does Coke taste so much better at McDonald’s? Popular food scientist Abbey Thiel is refreshing our memories.

The special formulation of McDonald’s Coca-Cola has long been the subject of conspiracy theories, with the international burger chain trying to tamp down speculation in 2021 by revealing that one reason why its Coke is soda-licious is that it filters every drop of water before it enters the soda fountains.

“Soft drink producers will usually have their own water supplier or a filtration system to increase the quality of water,” Thiel explained to Parade last week.

“Most often, chlorine is removed as it can result in a ‘disinfectant’ taste, the water hardness will be adjusted since it affects the acidity of the drink, and iron will be removed to limit color and flavor defects,” she continued. “Without this treatment, the end result is a Coke that has off-flavors and aromas due to low-quality, inconsistent water.”

Earlier this year, the Reddit post “Does McDonald’s Coke really taste the best?” generated debate about whether the best Coke could be found at McDonald’s or Walt Disney World.

“Hands down, my favorite place to get a coke,” one fan fawned about McDonald’s.

“It’s the straw that makes it. I used to get McDonald’s on the way in to the pizza place I ran,” another devotee dished. “I’d refill with our coke and it’d taste the same. I’ve also gotten mcd and forgot a straw so used our thinner ones. Taste nothing like mcd coke. Sounds [weird] but try it. Needs to be a big straw.”

McDonald’s bosses agree, explaining in the 2021 post that their straw “is slightly wider than a typical straw so all that Coke taste can hit your taste buds.”

Another key distinction is that McDonald’s pre-chills the water and Coke syrup before they go into fountain machines in a special ratio that factors in melting ice.

“Most products are traditionally prepared as a syrup‐plus‐water mix, in a ratio of some 1 part (volume) syrup to between 3 and 6 parts (volume) water,” Thiel told Parade. “This allows a concentrated batch of syrup to be made and then proportioned with water to form the final product.”

McDonald’s also pointed out that its dispensers remain cold, which Thiel says helps maintain the carbonation level to keep the soda perfectly bubbly.

And in 2014, The New York Times reported that Coke delivers its syrup to McDonald’s in stainless steel tanks instead of in plastic bags, as it does for other restaurants, to ensure freshness.

“Facts McDonald’s fountain coke hits different,” one Redditor concluded.