Over the past couple years I've started thinking more about individual ingredients, both in cooking, and those used as flavorings in tea. Cloves are an interesting spice. They're fairly mainstream--something you might expect to find in anyone's cupboard--but they're also not necessarily the most versatile of spices: a lot of people may go for a long time without using them in anything, and they certainly don't go well with all foods.
Cloves have a strong, distinctive aroma, which can easily overpower other spices or flavorings.
Tulsi, or Holy Basil, and Other Basils, Resemble Clove:
As distinctive as cloves are, their aroma is not completely unique. There are a number of other plants, including unrelated ones, which have aromas sometimes suggesting clove. The plant that I've found that most closely resembles clove in aroma is tulsi, or holy basil. I find holy basil has a warmer and gentler quality than clove, which can come across as harsh or dominating.
Not surprisingly, these plants both share the same primary component of their essential oil, a chemical called eugenol. Eugenol is a biologically-active compound, and is responsible for many of the medicinal properties of both cloves and tulsi, such as the anaesthetic properties of clove. This chemical is also present in other species and varieties of basil, including regular sweet basil, giving other basils a clove-like quality as well.
Cloves in Masala Chai:
Cloves are usually only used to flavor tea in the context of masala chai or spiced tea. Because cloves are so strong and distinctive, adding clove alone to tea will generally give the tea more of a "spiced" character, even if you do not add any other spices. My own perception is that if I add cardamom to tea, I'll taste "tea with cardamom", whereas if I add cloves to tea I'll taste "spiced tea".
I find that cloves go most well with strong black teas, such as Assam. Lighter teas tend to be overpowered by the clove aroma. Personally, I rarely like adding clove to anything other than black tea; the aroma does not seem to blend well with green, white, or most oolong teas, although I could imagine clove might go well with some of the very dark, roasted oolongs. I also rarely use cloves in tea on their own: I usually blend them only as one spice among many, and I tend to add only a hint of them, using other spices, like cardamom, as the dominant character.
When I add cloves on their own to anything hot, it's to hot fruit juice, especially cranberry juice or a blend of cranberry and orange. Especially when I have a cold, in the winter, I find that a mix of orange and cranberry with clove often makes me feel a lot better.
What do you think of cloves in tea?