It's a well-known fact that soda tastes different when you drink it out of a bottle than when you get it out of a soda machine. What you may not know is that it's not just your imagination--Coke (or Pepsi or any other type of soda pop) can actually be different depending on the method of delivery.
It's not that the soda maker (or any other carbonated beverage producer) has a different recipe for the drink that goes into bottles and the drink that goes into a soda machine. But when you get a cold beverage from a soda machine, you're getting a different process that mixes the syrup with the carbonated water.
In bottles or cans, the process is already done. All you have to do is pop the top and drink. But when you get a drink from a soda machine, the mixing process depends on the restaurant.
A Washington, DC restaurant owner walked The Today Show through the soda machine mixing process. Gina Chersevani said that the taste of a soft drink depends on the carbonation, the ratio of syrup to water, and temperature.
We've all gotten a soda from the machine at a fast food restaurant only to find out it's flat. That's because the restaurant hasn't kept the pressure on the soda machine calibrated, which is necessary to keep the carbonation fizzy.
It's in the Syrup
The amount of syrup mixed with the carbonated water matters, too. The more syrup you get, the sweeter the drink is. But that's not always a good thing (even aside from the giant amount of sugar found in sodas). There is a recommended amount of syrup to add to the water; McDonald's, for example, says they follow the specific guidelines given to them by the Coca-Cola company and they're well known for serving the best Cokes in the fast food business. McDonald's also notes that the ratio is built around how fast ice melts.
The Temperature Matters
Temperature is also a key point in getting the best drink from a soda machine. Chersevani said, "The carbonation will fall apart almost instantly if it's not cold." McDonald's website states that as part of their adherence to the highest standards, the syrup and soda water is pre-chilled before it goes into the soda machine dispensers and the soda fountain is kept cold so that the whole system provides the optimum cold drink.
Ice also plays a role in the taste of the drink. Besides keeping it cold, if the ice melts too fast, it can water down the drink. Chersevani likes crushed or "chewable" ice best because its surface area allows for the bubbles in carbonation to grab onto the ice. (Which validates the reason why Sonic drinks are so good.)
Go for the Glass?
Not everybody likes soda from a soda machine best, though. Some people swear by the glass bottles and some will only drink from a can (does anyone actually prefer the plastic bottles?). Temperature and carbonation affect the taste of the drink in each type of container, giving the same recipe a slightly different taste.
Glass bottles keep the drink the coldest the longest, followed by aluminum cans. Plastic bottles, as you know, don't do a great job of keeping beverages cold once they're out of the fridge. However, aluminum cans are porous and allow more carbonation to escape, while plastic bottles keep all the good carbonation trapped where it's supposed to be.
If you want to have some fun, hold your own taste test to see what you like best: the soda machine drinks or soft drinks from a can or bottle.