Shop Oolong or Wu Long Below
Both spellings are correct when discussing this bulk herbal semi-fermented tea. 

The two are exactly the same in some research articles and other articles states that wu long is a type of oolong tea.  Though I have researched several articles I have not able to figure out what the exact difference is.   Here is what I have found out about oolong tea though.

What is oolong tea?  Unlike green tea that is not fermented and black tea that is totally fermented, oolong tea is only partially fermented.  For me I think of it as in the story of Goldie locks and the three bears.   This one is too hot, this one is too cold, but this one is just perfect.    Oolong tea is semi-fermented, that is, moisture is kept within the leaves for a longer period of time than the green tea leaves. After wilting, the usually larger, older leaves are carefully rolled around on rattan trays in order to "bruise" their outer edge.  The range of oxidation can vary from 8 to 85%, depending on the variety and the desired ending results.

The black outer and green inner parts of the herb leaf give this tea its characteristic qualities. The color is usually a light brown and can sometimes reveal a slight fruity taste. Some high grade Oolong leaves can even be brewed up to 10 times without fading in flavor.  Oolong tea is so popular in Asia that many times Oolong tea is served at weddings instead of Champaign.  It is also stated in folklore that by drinking oolong tea twice a day you will maintain a perfect weight.  Oolong tea contains vitamins, minerals, amino acids and tea polyphenols.

Oolong teas have a wide flavor profile. Oolongs are often harvested from Camellia sinensis trees that are over 100 years old.  The flavor of the tea is effected by the drying process and how much oxidation the leaves undergo.  The taste can range from sweet and fruity to a rich woody flavor.  As with taste, the aroma can also range from a light sweet smell to a full bodied roasted smell.  The wide variation of taste and aroma gives the tea enthusiast and adventure in flavor!

Most people have tried Oolong tea, but may not know it.   If you have ever gone into a Chinese or Japanese restaurant and a pot of tea was severed, it was most likely Oolong tea. (a beautiful shade of tea which has a fantastic aroma) An enjoyable tea, which is known to benefit digestion.  It calms the stomach when consumed hot.  

Brewing Oolong Tea the Proper Way. 
Easy to do, but certain steps can't be left out or the bulk oolong tea will be "dull".  And what I mean by dull is really bad tasting bitter unpalatable tea.

• Step 1: Start with cold water.
• Step 2: Preheat your teapot: Simply boil enough water to fill the teapot one and one half time.  Pour the hot water into the teapot, swish it about.  This will heat the teapot up.  Then pour the used water out. Many people do not do this.  Without doing this step your tea becomes luke warm quickly.
• Step 3: Measure into the teapot 1 tsp. of loose tea for every cup you plan to pour, plus one for the pot.  Trust me on this, it will make a difference.
• Step 4: For black teas, bring the water to a full boil. Remove the teakettle from the heat as soon as the water begins to boil. Boiling all the oxygen out of the water will flatten the tea's flavor.
• Step 5: For more delicate green teas, remove the teakettle from the heat before the water begins boiling, at 165-170 degrees F (74-77 degrees C). Or you can add 1 part cold water to 4 parts boiling water to cool it to the ideal temperature range.
• Step 6: Before steeping, pour a small amount of the hot water over the tea leaves, to allow them to bloom, or open up, and release some of their bitter tannins. Drain immediately.
• Step 7: Fill the pot with the boiling water. Keep the spout of the kettle close to the teapot, so the water does not cool as you pour it in. Cover the teapot and leave the tea to brew. In general, black teas are best brewed for 4 to 5 minutes; green teas should brew for no more than 3 minutes.
• Step 8: When the tea is ready pour. Avoid keeping the leaves in contact with the hot water. Over-brewed tea will become better and unpleasant.

On a personal note, in the morning, when I am running late, I set my Keurig on to 169 degrees, fill the reusable purple basket up half way with my loose leaf oolong tea, and set it for 20 ounce size cup.  Now I do realize that this doesn't let it "bloom" tea leaves as it should.   But I would rather have it this way than miss my oolong tea all together.   It just wouldn't be a great day without a kiss and a cup of oolong tea as I am leaving for work.