According to Spoon University, it all boils down to storage, water filtration, temperature, syrup and the straw. Yes, even the straws at McDonald’s are a little different.
According to McDonald’s, the company follows Coca-Cola’s exacting guidelines to make sure the beverage is as consistent in taste as its bottled soda. To begin with, the syrup is delivered in stainless steel containers to help preserve the flavor of the ingredients. The company explains, “water and Coca-Cola syrup are pre-chilled before entering our fountain dispensers with the ratio of syrup set to allow for ice to melt.”
The temperature is also very important. While McDonald’s has been known in the past for their hot coffee (so much so that they’ve been forced to add a warning label for customers), but it should probably be recognized for its cold carbonated beverages. Cold temperatures hold carbonation better, so by serving it just a little cooler than their competitors, McDonald’s is able to make the carbonation last longer and more bubbly means a better taste.