The Standard Evaluation Procedure: Pu'er Under GB/T 23776
When tea factories buy maocha, competitions award prizes, or testing bodies issue reports, every tea first has to start from the same line. China's national standard GB/T 23776-2018, Methodology for Sensory Evaluation of Tea, is that starting line. Issued on February 6, 2018 and implemented on June 1, 2018, it fixes the rules for equipment, leaf amount, water volume, time, and scoring. In this methodology, pu'er falls under the procedures for dark tea and compressed tea. Understanding the procedure will make your own tea comparisons at home more methodical too.
Preparing for Evaluation
The standard calls for evaluation in a qualified evaluation room, with natural light from the north or a standard light source, no odors in the room, and stable temperature and humidity. The conditions of the evaluation room are governed by a separate national standard, GB/T 18797. All the equipment is white: white porcelain evaluation cups (with a serrated pouring notch at the rim), white porcelain evaluation bowls, spent-leaf trays, and sample trays, plus a scale accurate to 0.1 g, a timer, a spoon, and a spittoon. The purpose of white is simple: nothing should interfere with the color of the liquor and leaves.
Boiling water is used, and the standard also requires that evaluation water meet drinking-water regulations. Before starting, evaluators don't smoke, wear perfume, or eat strongly flavored food, and keep their mouths clean.
How Many Grams of Tea, How Many Milliliters of Water?
Loose pu'er is evaluated using the cylindrical-cup method, at a tea-to-water ratio of 1:50, with two common combinations:
| Cup | Leaf amount | Water |
|---|---|---|
| 150 ml cup | 3.0 g | 150 ml |
| 250 ml cup | 5.0 g | 250 ml |
Both combinations give the same concentration, so use whichever matches the evaluation cups on hand. For compressed tea (cakes, bricks, tuos), samples are first taken from different parts of the whole piece, some from the surface, center, and edge, broken into similar-sized pieces, and weighed to the same amount, to avoid sampling only the attractive buds sprinkled on the cake's surface.
Why Brew Twice?
Pu'er is rich in soluble compounds, and compressed tea needs time to open up, so the standard uses two infusions:
| Infusion | Loose tea time | Compressed tea time | Mainly evaluates |
|---|---|---|---|
| First | 2 minutes | About 2–5 minutes, depending on compression | Mainly liquor color, plus a first smell and sip |
| Second | 5 minutes | About 5–8 minutes, depending on compression | Mainly aroma and taste, then the spent leaves last |
In the first infusion, the leaves haven't fully opened, so the liquor color best reflects the tea's true color. The second infusion is fully extracted, so the persistence of the aroma, the thickness of the taste, and whether bitterness and astringency dissolve all come through completely. Only by putting the two together can you see a tea from start to finish. The more tightly compressed it is, the slower it opens, so times move toward the upper end of the range.
The Order of Evaluation
- Dry evaluation of appearance: Place the sample on a sample tray and look at the leaf shape, color, wholeness, and cleanliness; for compressed tea, check whether the shape is regular, whether the compression is appropriate, whether the surface is smooth, and whether layers are flaking off.
- Wet evaluation of liquor color: Look at the color, brightness, and clarity while the tea is hot, right after pouring.
- Smelling the aroma: Smell it hot to identify the aroma type, warm to judge its purity, and cold to judge its persistence.
- Tasting: Let the tea cool to around 50°C (122°F) before tasting; when it's too hot, the tongue can't judge accurately. Take a spoonful, swirl it around your mouth, and assess strength, mellowness, bitterness and astringency, and huigan.
- Examining the spent leaves: Tip the spent leaves into a tray and look at tenderness, color, evenness, and softness.
The fixed order isn't for ceremony; it's because liquor color changes with temperature and time, and aroma fades as tea cools. Get the order wrong, and your judgment will be skewed.
Scoring Weights
Each factor is scored out of 100, multiplied by its coefficient, and summed for a total score. The coefficients in the standard's appendix vary by tea category; for pu'er, these two sets are commonly cited:
| Factor | Loose dark tea | Compressed tea |
|---|---|---|
| Appearance | 20% | 20% |
| Liquor color | 15% | 10% |
| Aroma | 25% | 30% |
| Taste | 30% | 35% |
| Spent leaves | 10% | 5% |
The calculation is straightforward: total score = appearance score × appearance coefficient + liquor color score × liquor color coefficient + and so on. For example, a loose tea scoring 88 for appearance, 90 for liquor color, 86 for aroma, 89 for taste, and 85 for spent leaves has a total of 88×0.2 + 90×0.15 + 86×0.25 + 89×0.3 + 85×0.1 = 87.9 points. When total scores are tied, individual scores are compared in the order taste, aroma, liquor color, appearance, spent leaves, and the higher one ranks first.
In either set, aroma plus taste account for more than half; how a tea tastes in the cup is always the focus. In Yunnan there are also a number of group standards setting their own evaluation rules for shaiqing maocha and ancient-tree tea, such as a single 4-minute infusion of 5 g of tea in 250 ml of water. The details differ slightly, but the spirit is the same.
Can You Do This at Home?
Yes, as long as you keep the conditions fixed:
- Use two gaiwans or mugs of the same size, each with 3 g of tea and about 150 ml of boiling water.
- Pour off the first infusion at 2 minutes to look at the liquor color, then pour off the second at 5 minutes to smell and taste.
- Serve the tea in white porcelain cups and look at the color by a window during the day.
- Finally, tip the spent leaves onto a white plate and compare color and softness.
Tea brewed this way is very strong; the point is to magnify the differences, not to match an everyday drinking strength. Once you've compared, enjoy the one you like best with everyday gaiwan brewing. For an introduction to evaluation cups, bowls, and tasting vocabulary, read Drinking Pu'er Like a Tea Evaluator; for how to assess each of the five factors, continue with Evaluating the Dry Leaf, Evaluating Liquor Color, and Reading the Spent Leaves.
FAQ
How many grams of tea does the national standard use for pu'er? A tea-to-water ratio of 1:50, commonly 3 g of tea with 150 ml of boiling water, or 5 g with 250 ml.
Why brew twice? The first infusion gives the most accurate liquor color; the second is fully extracted, so aroma, taste, and spent leaves come through completely. Only together do they show the whole picture of a tea.
How long is compressed tea steeped in evaluation? Depending on how tightly it's pressed, about 2–5 minutes for the first infusion and 5–8 minutes for the second; loose tea gets 2 minutes and 5 minutes.
How are the scoring weights divided? For loose dark tea, commonly appearance 20%, liquor color 15%, aroma 25%, taste 30%, spent leaves 10%; for compressed tea, commonly appearance 20%, liquor color 10%, aroma 30%, taste 35%, spent leaves 5%.
Won't it be too strong if I do this at home? It will be stronger than usual, which is for the sake of comparison; once you've compared, pick the tea you like and drink it brewed the everyday way.