Yes I just mean the more expensive tea on the shelf. On cheaper SKUs they're trying to cut cost so they use normal tea bags. The plastic sachets were a trend for a couple years but hopefully most brands have switched away.
That study is interesting because they used SEM to image the plastic afterward, and you can see how the plastic surface has literally been torn up on a microscopic level simply by touching hot water.
Plastic has a low-energy surface, which means it doesn't take much energy to tear it apart. Even Brownian motion is enough, which is pretty wild.
> Or is there really a difference in the quality/taste of the expensive ones?
If we are still talking about tea, then of course there are huge differences. And the best tea is not packaged in individual tea bags (also it's not sold in supermarkets unless it's a country with a very high tea culture).
So at the low end you would have tea that is grown with lots of chemicals, plucked by machines or by badly paid workers, industrially processed in high quantities, sold as bulk on international markets. While on the highest end you would have artisanal small-batch tea with no chemicals involved, possibly grown in some special way like the tea bushes shaded from the sun or hundred years old tea trees in forested areas, processed by hand so the leaves are not broken etc... And all of this is reflected in the taste.
And to add - tea is graded at source, and buyers purchase based on grade. So a low quality tea bag will have tea that is objectively worse than a high quality one, while the best tea is never near a bag.
