Alright not my deepest question I’m sure, but I’ve always wanted to ask…
If the major soda manufacturers have a formula that is sold as syrup to all the different fast food chains (Popeyes, Burger King, Chick-fil-A…etc) Why do all their drinks (let’s say Coca-Cola) taste different? I do understand some restaurants mix more of the CO2 into their drinks than other restaurants, but can the taste difference really just be this?
Of all the fast food places I eat at I’ve found Chick-fil-A’s Coke to be the most authentic tasting to something I could buy in a can.
Anybody else notice this taste difference?
It’s not just the CO[sub]2[/sub]. Water tastes different depending on the location and whether the restaurant has a purification system. That’s most of the difference.
Robin
Also, different wait staff may be adding different amounts of spittle to your drink.

The syrup strength is also variable amongst different machines, and the level left in the box. As the box empties, more air gets pumped instead of syrup. Also, machines can be calibrated differently, dispensing different mixtures of both syrup and carbonated water.
Who’s in charge of cleaning the lines, the restaurant or the distributor? Dirty lines can add… “flavor” to the beverage.
I vote for cleaning of the lines, along with the different mixes of CO2 and sugar mix. Worked in a bar for a few years, and I seem to remember that the Budweiser always would taste funny after a few months. Fortunately, we had a “bar clean” from top to bottom every 6 months. Everybody got into the action, to include changing the lines that ran from the walk-in cooler (with the kegs) and the warm cooler (where the soda syrup was kept). After that, everything tasted fine for a few months.
I dislike fountain sodas for this reason. No two establishments (restaurants, convenience stores) have the same methods of quality control. I trust the bottling plant methods and quality control more.
One more thing. Fountain diet soft drinks may use a different sweetener than their bottled counterpart. I don’t like Diet Coke from a fountain even though I’ll drink gallons of the canned/bottled stuff.
Robin
McDonald’s gets their syrup in large steel containers, while other retailers may used the bag-in-a-box setup. These are filled on different lines at the syrup manufacturing plant, and may have different “born on” dates depending on how the distribution system works.
First, syrup remaining doesn’t matter as to quality. It’s a bag, and like wine-in-a-bag, the bag collapses around the syrup as it’s sucked out. No air gets in. For places that still use metal containers, they have dip tubes for extraction. No air gets in, either.
Quality variation between locations can be attributed to water quality, syrup age, water-syrup ratio, and carbonization level.
Line cleanliness can be an issue with soda-pop only if the line becomes dirty. This is less of an issue with soda-pop than with beer, though, since nothing can live in such a sugar concentration, and carbonated water is essentially sterile. With kegged beer, though, line sanitation is extremely important, because kegged beer isn’t pasteurized. (I sanitize my lines and taps every time I change the keg, because the flavor change does become noticeable.)
The amount of CO2 dissolved in the water also drastically changes the mouth-feel, which for sugary beverages affects perceived taste. When I make soda water it’s not a big deal. When I make soda-pop, I have to use a scale to make sure I add the “right” amount of CO2 to the filtered tap water. The “right” amount is just a consistent amount per volume; your tastes will vary.