I looked up “zavarka” and I guess it has more cultural significance than I give it. In my family, zavarka (literally “brew” in Russian) is just the pre-brewed tea you get when you leave a tea-bag/ball in a little container of hot water for hours. It’s done more for the sake of convenience, so that you can just dilute the zavarka in your glass whenever you don’t want to wait for a fresh cup to brew. I use it when I want cold tea because the zavarka cools down and I can mix it with cooled or room temperature water (I never drink ice tea).

Then again, it can be said that I always drink zavarka. When I lived in USSR, we never had the concept of “you have to brew this tea at this temperature for this many minutes.” All tea was brewed in boiled (or even boiling) water indefinitely. I only learned otherwise when I started reading books about tea, and I’m still far from strict about this. I now pay attention to water temperature for green, white, and oolong teas, but I’ll still leave the tea in the water indefinitely and just microwave the glass if it gets too cold.

Growing up with zavarka makes me feel like taking tea out after 2~4 minutes robs it of much of its flavor. One of my favorite teas (one of the very few I enjoy drinking without added stevia) is this mix of sencha and matcha. The instructions say “steep for 30 seconds,” and I just LOL so hard at that. I leave the bag in until the tea is cool enough for me to drink. :P Some tea will develop “metallic” flavors if I steep it too long, which I don't like, so I won’t steep those for longer than is recommended. But I haven’t found this to be a problem with most teas. It gives them a stronger brew, of course, but I like that.