Brewing is more appropriately use an alcohol making term. Steeping tea is really quite easy. Here are some instructions for brewing a perfect cup of tea.
By far, the best way to brew tea is to use a tea infuser and pour the hot water over the tea leaves to steep.
First start with cold, great tasting, water. If your tap water does not taste good, then use filtered or bottled water. (I say to use cold water because a typical hot water heater will often add contaminants and reduce the amount of oxygen in the water, which is needed for flavor extraction).
Then bring the desired amount of water to a rolling boil. (Do not boil the water for a long period of time because this too will deplete the water of oxygen).
Put approximately 2 grams or 1 tsp. of tea leaves per 6-8 oz. of water into a pre-heated pot or cup (pre-heating will allow the tea to steep at the proper temperature). For white, silver or herbal teas use 2 tsp/ per 6-8 oz. cup.
Then add hot water (pouring the water over the tea leaves is best) according the chart below for the type of tea you are brewing. Please note that these are general guidelines. If your tea container has brewing instructions I would follow those as they are probably ideal for that specific tea.
About Water Temperature
The water temperature does not have to be exact. The main thing to remember is to not use boiling water for Green or White teas. They will burn and create bitter flavors.
A good way to guess at the water temperature without a thermometer is to bring the water to a boil, and wait about 30 seconds (for white tea) or 60 seconds (for green tea) before pouring over the leaves. Another quick way to judge water temperature is to look for the tiny bubbles before the water come to a full boil and take it off the heat.
About Steep Times
The amount of time that the tea steeps will determine its strength. I enjoy different teas at varying strengths. I would suggest that when you buy a new tea, as it is steeping, check the taste every minute with a spoon. This way you can blow on it so you won't burn your tongue!
Let the first cup steep until it's either too strong or you notice bitter elements that are unpleasant. Then take note of when the tea tastes best to you and write it on the package. Besides, who can tell you how you like your tea better than you!
Make Your Own Decaf Tea
You also may substantially reduce the caffeine content in regular tea to make your own decaf tea by steeping it for approximately 30 to 60 seconds, then dispose of the tea or serve it to someone in need of caffeine. Then, using the same tea leaves, make another cup of tea which will contain much less caffeine since most of it was dissolved in the first cup of tea. Most of the caffeine dissolves in the first 30 to 60 seconds. It actually takes at least several minutes of steeping to start extracting the beneficial substance from tea, such as polyphenols.
General Tea Brewing Guidelines
Black Tea Rolling Boil 3 - 5 minutes
Herbal (tisanes) Rolling Boil 7 - 10 minutes
Green Tea 160 degrees F 2 - 3 minutes
Oolong Tea 190 degrees F 2 - 8 minutes
Pu Erh Tuo Cha (Break or chop the Cake) Rolling Boil 10 mins. - Overnight
Rooibos Tea Rolling Boil 3 - 5 minutes
White/Silver Teas Use 2 tps. Per Cup 180 degrees F 3 - 4 minutes
Although each type of tea has a different shelf life, it's best to use or tea within 6 to 12 months of purchase. Green teas perish the quickest and begin to deteriorate within a year of harvest. Oolong and black teas retain their characteristics for several years.
Keep your loose-leaf teas stored in a cool, dark place to preserve their freshness. Avoid exposing the tea to light. Always store your teas in opaque (non-clear) jars with airtight lids.
Another factor contributing to a tea's longetivity is the way in which the tea leaf is rolled. Tea leaves rolled into pellets (Gunpowder and Imperial green teas) or twisted (like the black Yunnan) last longer than an open, flat leaf, because less of their surface area is exposed to air. Whatever tea you choose, remember to treat it as you would a delicate spice. Keep it away from heat, moisture, and, of course, other strongly scented teas or spices.