Water for Tea: Change the Water, Change the Taste

The ancients said, "Water is the mother of tea." Brew the same tea with different water, and its aroma, sweetness, and texture will all change. You don't need to fetch water from a mountain spring to brew pu'er at home, but understanding water's properties can make the tea you have taste better.

Soft Water and Hard Water

Water "hardness" refers to how much calcium, magnesium, and other minerals it contains:

• Soft water: Fewer minerals; the tea it brews has a clear aroma, bright color, and smooth mouthfeel.
• Hard water: More minerals; the brew tends to darken, the aroma is muted, and the mouthfeel leans astringent.

For pu'er, soft or moderately hard water is generally recommended. Tap water hardness varies across Taiwan; some places in the south and east have harder water, and white scale building up in your kettle is a sign of higher hardness.

Common Choices

Filtered Tap Water

The most convenient choice. Use a water filter to remove residual chlorine and impurities, then boil, and in most cases it works very well. Letting filtered water sit a while before boiling reduces the chlorine smell even further.

Bottled Mineral Water and Purified Water

• Mineral water: Choose one that's low in minerals and tastes clean for better tea; high-mineral water tends to darken the brew.
• Purified or distilled water: Very soft, producing tea with a clear aroma, though some people find the texture a bit thin. Try comparing it with ordinary filtered water.

Spring Water

The quality of spring water varies widely. Make sure the source is clean and boil it before use.

Boiling Tips

• Bring it to a full boil: Pu'er uses water at 95–100°C, so bring the water to a full boil.
• Don't boil it repeatedly: Boiling the same water over and over reduces the dissolved gases, making the tea taste flat. Fresh water each time is best.
• Don't skip warming the teaware: Hot water poured into cold teaware loses about 5°C, so warming it first keeps the water temperature stable.

Try a Little Experiment

Get two or three kinds of water (such as filtered tap water, a brand of mineral water, and purified water), and brew the same pu'er with the same amount of leaf and time, one cup each, side by side:

1. Look at the liquor color: Which cup is brightest?
2. Smell the aroma: Which cup has the clearest aroma?
3. Taste: Which cup is sweetest and smoothest?

Do it once and you'll see that water makes a bigger difference than you'd expect, and you'll find the one that works best in your home.

Water for Cold Brew

For cold-brewed pu'er, use boiled water that's been cooled or bottled water that's safe to drink as is, in a clean container in the fridge. See how in Cold-Brewed Pu'er.

Water Temperature and Tea

Water temperature affects not just strength but also the balance of flavors:

• Higher temperature: Compounds in the leaves dissolve faster and in greater amounts, the aroma rises, and the texture is full, but more bitterness and astringency come out too.
• Lower temperature: Slower extraction, less bitterness and astringency, and a gentler mouthfeel, but the aroma and body may fall short.

Pu'er is usually brewed at 95–100°C because the large-leaf variety's leaves are thick and need high heat to fully release their aroma and flavor. If a young raw (sheng) pu'er is noticeably bitter and astringent, lower the water to around 90°C; ripe (shou) pu'er and aged tea always need boiling water.

How to Pour

• Along the side of the bowl: The water runs down the inside wall of the gaiwan rather than hitting the leaves directly, giving a softer brew. Good for young raw pu'er.
• Directly onto the leaves: Pouring right onto the leaves helps compressed tea break apart. Good for the first few infusions of dragon pearls and tightly pressed bricks.
• Pour high, serve low: Hold the kettle a bit higher when adding water so the leaves tumble; keep the spout low when pouring out the tea to avoid foaming and losing aroma.

Taiwan's Water: Softer in the North, Harder in the South

Tap water in Taiwan must meet the Drinking Water Quality Standards by law, which set an upper limit of 300 mg per liter for total hardness and 500 mg per liter for total dissolved solids (TDS). Within those limits, water varies quite a bit from place to place, mainly because of the geology the source water flows through:

• Taipei area: Water comes mostly from the Feitsui Reservoir and the Xindian River. Media reports put Taipei's average raw water hardness at about 74 mg per liter, fairly soft water that's very friendly to tea.
• Kaohsiung area: Water comes mostly from the Gaoping River. The same report put Kaohsiung's average total hardness at about 247 mg per liter, with some water purification plants close to 300 mg, and kettles there scale up especially easily.

High hardness doesn't mean the water is bad; it just has more calcium and magnesium. For tea, though, calcium and magnesium bind with compounds in the brew, darkening the liquor and muting the aroma. That's why tea lovers in hard-water areas often brew with a water filter or a softer bottled water.

Reading a TDS Meter

You can buy small TDS meter pens that display a number when you dip them in water, in ppm (roughly mg per liter). They measure the total amount of dissolved substances in the water and can serve as a reference for whether water is "light" or "heavy":

• Very low readings (such as reverse-osmosis or distilled water, often in the single digits up to twenty or thirty): Clear tea aroma, though some people find the texture thin.
• Mid-range readings (typical filtered tap water, most soft mineral waters): The range most tea lovers find most balanced.
• Very high readings (some mineral waters, tap water in hard-water areas): The liquor tends to darken and the aroma gets muted.

TDS is only a total; it isn't the same as hardness. Two waters with the same reading but different mineral makeup will brew different tea. The most reliable approach is still to brew the same tea with the same leaf amount and time in several waters side by side and let your own palate decide.

Scale and Teaware

In hard-water areas, kettles and gaiwans easily build up white scale. Scale is simply calcium and magnesium deposits, and it's easy to deal with: fill the kettle 80% full of water, add 1–2 tablespoons of citric acid, bring to a boil, and let it soak 30 minutes to 1 hour. Pour it out, then boil plain water once or twice. Descaling regularly also makes the boiled water taste cleaner. For everyday teaware care, read Caring for Teaware.

FAQ

Can I brew pu'er with hot water from an electric hot water dispenser? Yes, but these dispensers often keep water at only about 90°C, which may not be hot enough for ripe pu'er or aged tea. It's best to bring it to a boil again.

What about hot water from a water cooler? Water cooler hot water is usually below boiling. It's fine for pyramid tea bags, but for loose-leaf pu'er, we recommend water that's been brought to a boil.

Is lower TDS always better for tea? Not necessarily. Very low-TDS purified water brews tea with a clear aroma, but the texture may be thin; most people find moderate, slightly soft water the most balanced. The best approach is to compare side by side yourself.

If I live where the water is hard, how should I adjust when brewing pu'er? Use a water filter, or switch to a low-mineral bottled water. You can also use a little more leaf to make the brew fuller.