Green tea is among the most popular style worldwide, but the huge variety in green teas can be overwhelming. Though the crafting steps of green tea are typically minimal, and the style is narrowly defined by the lack of oxidation, the range in green tea flavor can be enormous, even before considering scented and flavored varieties. To narrow down the options to more a more specific selection of flavor profiles, we recommend asking about harvest date.

Harvest date is the primary criteria for grading traditional Chinese green teas, with the first leaves picked during the year fetching the highest prices. But the most expensive tea is not always best for every palate, and exceptions exist to every rule. So how exactly does harvest date contribute to quality? And what factors can change the impact of traditional harvest dates?

We love traditional teas, and we believe that expertise passed down through generations of tea farmers and crafters is key to maximizing quality. But we also know the value of innovation. Many of our favorite teas are produced in new and unique ways, whether it’s the experimental oxidation level of our Xin Gong Yi white tea or the blend of varieties in our Three Cultivar Red black tea. And in this modern age, most of our best teas are crafted with the help of machinery, which helps automate crafting processes long done by hand.

It may not fit the romantic image presented to tourists or pictured in documentaries, but the advantages of using machines in the crafting process are hard to deny, especially as premium tea farms face labor shortages and volatile weather conditions. While teas harvested or crafted by machine are sometimes derided by purists, artisans making every style of tea now use machinery specifically developed to mimic the traditional methods of crafting that have been passed down to them. Rather than compromising the quality of the tea, these machines help maintain quality, consistency, and cleanliness during the production process.

During our annual sourcing trips to China and Taiwan, we are presented with a variety of teas at each farm we visit. Some farms grow many different varieties of the tea plant, but every farm produces many lots of tea throughout the harvest season, with differences based on the exact day of harvest and minor adjustments in crafting techniques. Our job is to discern the most subtle of flavor differences and curate our selection to include only the very best. To ensure we get an accurate tasting, we use our own version of the gong fu cha brewing method. Here are the steps we take to gauge the quality of every tea we get the opportunity to taste.

As direct importers, we made the conscious choice many years ago to source from small, family owned tea farms, despite the extra level of difficulty this adds to our buying process. While large, commercial farms can produce teas with great consistency at inexpensive prices, we choose to seek out smaller, family-owned tea farms that focus on quality over quantity. Often, we have to look far and wide, well outside of the normal boundaries of famed tea markets or major cities. In return for the extra effort of annual sourcing trips through rural mountainous regions in China and Taiwan, we are rewarded with better quality of flavor, inherent sustainability, and an infinite variety of new tea possibilities.

One of the things we love about working with traditional tea farms is that the growers we work with are primarily concerned with how the tea tastes, rather than how much they can produce. With this focus on quality over quantity, we are free to appreciate the ways in which even subtle differences in growing conditions can dramatically change the final flavor in our cup. By tasting several lots of tea from the same farm or season, it is easier to isolate specific variables like changes in weather patterns between different farms or years, or even between specific weeks during the harvest season.

Differences in weather between seasons are one of the most important factors in the overall grade of the finished tea, and often correlate to levels of bitterness or astringency as the plant grows more mature leaves throughout the annual growth process. Differences in regional weather patterns, along with local flavor preferences and crafting styles, define ideal harvest dates for each type of traditional tea. And variations in weather patterns, whether from year to year or week to week, keep growers, crafters and tasters on their toes, ensuring that no two harvests taste exactly the same.

Oolong teas compose one of the most varied categories of tea because they cover the entire range of oxidation levels between green and black tea. Newcomers to this category might be surprised to find that two teas called “oolong” could be completely different in aroma, flavor, and even leaf shape. In fact, there are four main types of oolong, hailing from four geographically isolated regions near the eastern coast of China. Each region has its own unique terroir and specialized varieties of Camellia sinensis, but the easiest influence to observe in the final flavors of the tea is each region’s specific crafting style. And one aspect of the finished tea that gives us a clue to crafting style is leaf shape.

As direct importers, we believe that transparency in the sourcing process is one of the best ways to ensure that tea production stays sustainable. We make it our mission to understand and share as much information as possible about any tea we carry, from the variety used to grow it, to the environment it was grown in, the harvest date when it was picked, and the way the leaves were crafted into finished tea. But this in depth knowledge depends on our personal trips to the tea farms we work with, and the control we have over each lot we source, from the time it leaves the farm to the time it arrives at our San Francisco warehouse. Not all teas have such a direct path to your cup. Here are a few of the twists and turns your tea might be making.

When we source new teas, we always make an effort to visit the farm and see for ourselves how the tea is grown and crafted. While the majority of teas are bought and sold through middlemen at large tea markets, we prefer to work directly with the farmers to ensure we can personally vouch for the quality of each tea we select, as well as provide accurate information about the variety, provenance, harvest date, and crafting style that give a tea its unique flavor profile.

At each farm, we wander through rows of tea bushes, meet pickers and crafters, and observe whatever stage of the process is currently in progress. These visits are our first line of defense against misinformation, and we’re always looking for signs that the teas we’re considering are farmed sustainably. Here are five indicators of a high quality, natural tea farm.