Do you have to use hot water make tea or can i just put a bag in cold glass of water?

You can technically put a tea bag in cold water, but it won't really make tea. Here's why:

* Temperature and Extraction: Tea leaves release their flavor and color through a process called "extraction." Hot water allows the compounds in tea leaves to dissolve more readily, creating a stronger and more flavorful brew. Cold water will extract some flavor, but it will be very weak and the process will take much longer.

* Time: Cold brewing tea can take anywhere from 4 to 24 hours to extract a decent amount of flavor. This is not a practical method for most people.

* Taste: Cold-brewed tea can have a slightly different taste than hot-brewed tea. It might be smoother and less bitter, but it won't have the same vibrant flavor profile.

So, while you technically can make "tea" with cold water, it's not the optimal way to get a good cup of tea. For the best flavor, stick to hot water!

If you're interested in trying cold-brewed tea, there are specific methods and recipes available online that use cold water for a longer period to extract a richer flavor.