Why Cola Tastes Different In Glass Bottles

Did you know cola is made with a kola nut? The ingredient, which is from Africa, is where the fizzy drink gets its caffeine from.

Of course, some cola brands keep the other parts of their recipe top-secret. But why do beverages made by the same company seem to taste different in a glass bottle, can, and plastic bottle?

Well, according to Rowland King, a director at the glass bottles supplier, Quality Bottles, there’s real science behind the difference.

First, there’s the chemistry of each material to consider.

“Glass is chemically inert and non-porous, which means it doesn’t react with the drink or absorb flavour compounds,” King said.

“That helps keep the taste exactly as intended from the moment it’s filled to the moment it’s opened”.

Some experts think the polymer lining of tinned fizzy drinks can lead to a milder taste, while it’s possible that acetaldehyde in plastic bottles could affect the flavour.

And carbonation (bubbles) matter, too, King added.

“Fizzy drinks rely on dissolved CO₂ for their bite and freshness. Over time, plastic is slightly permeable to gas, even when sealed.

“Glass isn’t, so carbonation is typically retained more consistently, which can noticeably affect the taste and how it feels to drink.”

The screw or crown caps commonly used on glass bottles provide a tighter seal, too, allowing less CO2 to escape.

“Bottle shape also comes into it,” King continued.

“A narrow bottleneck concentrates aroma and slows down how quickly the drink hits the palate. That subtly changes the flavour perception compared to drinking from a wide can opening or pouring into a cup.”

I personally love an ice-cold can of diet cola – sometimes called a “fridge cigarette” – because I feel like it stays cooler and crisper than plastic bottles.

But King explained, “Glass bottles are thicker and tend to chill more evenly and stay cold a bit longer once removed from the fridge. Since temperature strongly affects flavour perception, that alone can make the drink seem more refreshing.”

Of course, companies try their hardest to make their product taste as consistent as possible across a range of containers, King stated.

But, he ended, “material science is material science. The container does make a difference, especially with carbonated drinks”.