https://wikiaboutcoffee.blogspot.com/2018/04/russian-tea-culture.html
Tea is one of the more popular beverages in Russia with the average person drinking over 3 pounds a year! Russians consider it customary to always offer guests tea, and it is polite to accept tea if offered. They even have a saying — having a “sit by the samovar” — to describe tea served with a bit of food or a light meal.
Zavarka…
However, in Russia, more tea leaves are steeped in less water to create a very concentrated brew called the zavarka, which is boiled for at least five minutes or possibly all day. This brew is then diluted with hot water when it is served. This concentrated strong tea brew is usually made especially for the Russian tea ceremony. The concentrate, is made in a small teapot that sits upon a samovar. The concentrate is then used to make a full cup of tea.
https://www.tripsavvy.com/what-is-zavarka-1502316
Backtracking…
Historically, the concentrate, it is said to be likely a product of the Russian Civil War in 1917, when the Red Army took over several large tea warehouses in Moscow, Odessa, and St. Petersburg. Before then, tea was sparse—something that only the über-wealthy could afford to drink. It’s difficult to pin point the origin of zavarka, which means “to brew” or “to cook” in Russia; but at some point in the 1920’s, workers discovered that it was most economical to brew a large pot of tea concentrate, and then have each individual dilute it according to their preference. Subsequently, this became the standard way of enjoying tea in Russia—and not just for the working class.
The beauty of this method, is that “you basically have the makings of tea for the rest of the day, because you can pour a little bit of the concentrate and water out for you or your guests whenever you want tea.” Also, back in the day, before the time of stoves, it was a big production to get water boiling. This way, both the tea and the water were always available, and without the risk of the tea becoming cold or too strong.
To make the tea…
A samovar is filled with water and placed over burning coals (nowadays, standard stoves are used). Once the water boils, some of it is poured into a smaller compartment of tea, creating the tea concentrate, or zavarka. To serve the tea, everyone is given a small quantity of the zavarka, and then they serve themselves the desired amount of boiling water from the spigot to dilute the tea depending on their tastes.
The Samovar…
One of the most interesting elements of Russian tea tradition is the equipment. To heat the water, a special device called a samovar was traditionally used. The samovar was an ingenious device that illustrates the Asian influence in Russian culture. Modeled after similar pieces of equipment used by the Mongols, the samovar consists of a large metal urn with a vertical pipe in the middle. The urn holds the water, and the pipe in the middle holds burning wood or charcoal. The fuel in the center heats the water to boiling, and then keeps it hot for the rest of the day. “The samovar is the centerpiece of the Russian table. Everybody has one.” In Russian families, the samovar is considered a precious heirloom—for rich families, it can even be made from precious metals, featuring intricate workmanship.
The samovar is also a thing of beauty. Most samovars are intricately designed pieces adorned with detailed metal-working or even paintings. Traditionally, for those who could afford it, the rest of the tea service was richly decorated as well. For example, Russian tea pots are usually made of porcelain, colored with deep pigments and often with gold accents as well. Tea drinking in Russia is an all-day affair and has been for centuries. A samovar could keep both water and zavarka hot all day long, so that a nice warm cup was always available. Of course, in the modern era many people have switched to electric samovars or have stopped using them altogether.
Now, not all teas…
The traditional tea of choice in Russia is Russian Caravan tea. This tea gets its name from the 18th century camel caravans that originated to bring teas and spices from southern regions of Asia up to Russia and Europe. Russian Caravan tea is a darker tea consisting of a blend of oolong, keemun, and lapsang souchong teas. This heavily oxidized tea it is perfectly suited to make the strong Zavarka concentrate. It will result in a brew that is sweet and smoky with minimal bitterness. However, any Chinese or Indian tea that can be steeped for a long time can be used for zavarka. Herbal or fruit teas can be blended with the black tea to make an even more complexly flavored zavarka.
How it is served…
Sometimes jam is served in a large bowl along with the pot of tea. If sharing with others, you might spoon out a little bit of jam for yourself into a smaller glass container. Then you would simply put a small spoonful of jam in your mouth and sip the tea through the jam. The preserves transform the flavor of the tea as it hits your taste buds, adding a totally different kind of sweetness than regular sugar cubes. And of course, with all the thick syrup gone with the hot tea, you’ve got yourself a tasty little morsel of fruit to chew on after every few sips. The Russians also use sugar, or honey. Instead of dissolving sugar into the tea, some Russian tea drinkers prefer to hold a sugar cube in their mouths as they drink -a recipe for tooth decay, but an interesting idea, nonetheless.
The ABC's of Tea 