Black tea. Black tea belongs to post-fermented tea, which is mild in nature and rich in vitamins, minerals and tea polyphenols. It can supplement human nutrition, improve immunity, remove oil and greasy, and help digestion. The winter climate in Northeast China is cold and dry, so people need to consume more nutrients and water to keep healthy. Black tea is a good choice. At the same time, black tea has a mellow taste and rich aroma, which can bring people a pleasant taste experience.