Reputable retailers specializing in premium loose tea will usually know the country of origin and sometimes the specific tea estate of their teas. They will know the health properties, brewing instructions and probably some interesting history of most of their tea selection. And most importantly, good tea retailer will be able to tell you when they received their latest shipment of your favorite tea.
on storing loose tea
Tea always needs to be protected from light and exposure. Light and air breaks down its properties and prolongs the oxidation period unnecessarily. Tea should always be kept in either tins or light protected bags and away from direct sunlight.
If a tea/coffee retailer has their tea in glass containers question the quality of this tea. Coffee retailers that sell tea usual do not focus their attention on tea. Tea is a sensitive plant and picks up strong odors especially coffee and buying tea from coffee retailers is a compromise over the quality, longevity and taste of the tea.
On average tea is good up to a year after purchase and after that year it is still enjoyable just not as flavorful nor beneficial.
Tea should always be brewed from 2-5 minutes depending on the tea (2 minutes for green) but herbs can be brewed as long as needed for desired strength and healing properties. Tea will become bitter if brewed too long however, herbs will have a stronger, bolder taste and enhanced nutrients.
Proper measurements of tea by the cup is 1 measured teaspoon per 6-8oz of water right before boiling point. Ideal water temperature is anywhere from 170-190F. Large leaf tea (usually white tea) 2 teaspoon should be added instead of the recommended 1 teaspoon.