Temperature, Time, Leaf: A Brew Guide for Sencha and other Japanese Green Teas

Have tea in the morning, goes an old Japanese saying, and you’ll escape the troubles of the day.

In the modern world, where disasters come with the swiftness of e-mail, the proverb still holds true. A tea break calms the mind down - and guides it to better decisions.

So if you can ward misfortune off with a cup of morning tea, imagine what an expert brew might do.

This guide will walk you through the essentials of Japanese green tea: the kinds, the chemistry and the art of brewing. If you understand why that cup tastes the way it does, you'll be able to tailor it to your liking.

The Different Kinds of Japanese Green Tea

Tea has taken every possible career path. From just one plant - camellia sinensis - you get brews ranging from the raised-in-the shade elegance of gyokuro to the deep smokiness of bancha, a tea that's been around the block.

The difference lies in the life experience the leaves have had - how much sunlight they received and whether they were steamed, rolled or roasted. Change the parameters and you'll change the personality of the tea. Here's an overview of the main players:

Sencha

The most popular green tea in Japan, sencha is grown under direct sunlight. The finest sencha comes from the first flush, when tender new shoots are plucked in spring. The second harvest yields a stronger, slightly more astringent brew.

Once picked, the leaves are steamed for less than a minute to prevent oxidation - a brief but crucial step that distinguishes Japanese green tea from its Chinese cousin, which is typically pan-fired. The steam locks in the tea’s bright green hue and grassy aroma.

After steaming, the leaves are rolled and dried. Rolling gives them their distinctive needle-like shape and releases the juices within, intensifying the flavor and aroma. The result is an interplay of sweetness, astringency and umami.

Fukamushi Sencha

Literally 'deep-steamed' sencha, this tea is steamed two or three times longer than regular sencha. This breaks the leaves down even further, producing finer particles and a green that's even deeper. The taste? Richer, rounder and less bitter.

Gyokuro

The crown jewel of Japanese teas; its name means 'jade dew' (玉露). Grown under shade for about three weeks before harvest then processed in the same way as orthodox senchas, gyokuro is characterized by strong umami, very little astringency and a sweet aroma.

Tencha

Tencha shares its upbringing with gyokuro - it’s also grown in shade, developing the same sweetness and umami. After harvesting, the leaves are steamed but not kneaded or rolled. They’re dried flat then the stems and veins are removed.

On their own, these leaves can be steeped but their true destiny lies in becoming quality powdered tea. The first character in their name, ten (碾), can be translated as 'stone mill' or 'to grind'. The second character, cha (茶), means 'tea' - but you knew that already.

Matcha

Matcha begins life as tencha, which is ground slowly in a stone mill until it becomes a powder so fine it could moonlight as eyeshadow.

Traditionally whisked with a bamboo chasen into a smooth, frothy suspension, matcha delivers a concentrated burst of flavor and the calming energy of shade-grown leaves. Once reserved for chado tea gatherings, it’s now a celebrity ingredient, appearing in everything from soba to soft serve.

Hojicha

Made by roasting sencha over high heat. The process produces a reddish-brown color and a toasty aroma. Lower in caffeine, hojicha, like bancha, is the go-to tea for evenings, especially at the end of a traditional Japanese meal.

Bancha

The working-class hero of Japanese tea, bancha tastes great hot or cold. Made from larger, mature leaves or stems harvested after the earlier flushes, it comes in many regional varieties.

The flavor is much heartier than sencha's delicate notes - imagine tea served in a thatched-roof farmhouse as smoke rises from the sunken hearth. The name 'bancha' (番茶) - 'everyday tea' - can also be written as 'late tea' (晩茶), a nod to its later harvest.

Genmaicha

A blend of green tea and roasted brown rice sometimes called 'popcorn tea' because a few grains pop during roasting. Mild in caffeine and big on comfort, genmaicha is the tea equivalent of a warm hug.

Caffeine, Catechin and Theanine: How Chemistry Affects Your Cuppa

Every cup of green tea is a small science experiment and its flavor depends largely on three compounds: caffeine, catechin and theanine.

Caffeine brings alertness and a slight bitterness. Think of it as the lively extrovert at a tea party. The younger and tenderer the leaves, the higher their caffeine content, so gyokuro and high-grade sencha pack more punch than hojicha or genmaicha.

Catechins are the antioxidants that bring astringency. They increase with exposure to sunlight, which is why shaded teas such as gyokuro have fewer catechins and more sweetness.

Theanine, however, is the real magician. An amino acid unique to tea and some mushrooms, it creates the savory taste called umami. Theanine doesn’t just enhance flavor; it also calms the nervous system.

First-flush and shade-grown teas such as gyokuro and matcha contain the most theanine, which explains their deeper umami, while roasted or sun-grown teas - hojicha and bancha - have less.

In short:
More sunlight = more catechins and caffeine = brisker, more astringent taste
More shade = more theanine = sweeter, umami-rich taste

Understanding this trifecta is the key to choosing between types of green tea.

There's Something in the Water

If tea were a band, the water would be the bassist: often overlooked but everything falls apart without it. Japan’s soft water - low in minerals such as calcium and magnesium - is exactly what's needed for delicious tea.

For brewing at home, use soft or filtered water. If you live somewhere with hard tap water - common in Europe and parts of the US - use a water filter or soft bottled water.

A simple test: if your kettle has scale buildup worthy of a geology exhibit, your water’s too hard for good tea.

Temperature and the Taste Equation

Here’s where brewing gets mathematical. Higher temperatures mean more extraction of caffeine and catechins, which has the effect of making the tea stronger but more bitter. Cooler water extracts more theanine, yielding a sweeter, softer flavor.

Recommended brewing temperatures:

• Gyokuro: 50-55°C (122-131°F)
• Sencha, Fukamushi Sencha: 70-80°C (158-176°F)
• Genmaicha: 80-100°C (176-212°F)
• Hojicha: 90-100°C (194-212°F)

And remember, 'temperature control' doesn't necessarily mean pressing a button. Pouring hot water into cups before you empty them into the teapot naturally cools it down by about 10°C.

You can also gauge how hot the water is by studying the steam. Here's how it appears at different temperatures:

• 90°C (194°F): Steam rises forcefully and straight upward.
• 70°C (158°F): Steam sways sideways as it rises.
• 50°C (122°F): Steam is faint and barely visible.

How to Brew Different Kinds of Green Tea

Time to put all this knowledge into practice. Reach for your kyusu (Japanese side-handled teapot), yunomi cups and a timer.

Sencha (Standard or Medium-Steamed)

Leaf-to-water ratio: 1-3g per 50ml
Water temperature: 70-80°C
Infusion time: 1st – 1 minute; 2nd – 0 to 10 seconds; 3rd – 45 seconds

Steps:

1. Boil fresh water and pour it into your teacups. This both measures out the amount of water you'll need and cools it to around 85-90°C.
2. Add 3-5g of tea leaves to your kyusu.
3. Pour the hot water from the cups into the teapot, lowering the temperature further to around 75-80°C.
4. Steep for 1 minute - no swirling, no agitation. 
5. Pour slowly and evenly, alternating between cups so that each gets a balanced taste. Empty every last drop - leaving tea in the kyusu will make the next infusion too astringent.

Fukamushi Sencha (Deep-Steamed Sencha)

Leaf-to-water ratio: 1-3g per 50ml
Water temperature: 70°C
Infusion time: 1st – 45 seconds; 2nd – 0-10 seconds; 3rd – 30 seconds

Steps:
Follow the same process as for sencha but reduce the steeping time slightly.

Gyokuro

Leaf-to-water ratio: 7-8g per 30ml
Water temperature: 50-55°C
Infusion time: 1st – 1.5-2 minutes; 2nd – 30 seconds; 3rd - 15 seconds

Steps:

1. Use small cups - gyokuro is concentrated umami, not a beverage to gulp.
2. Cool your boiled water by pouring it between the cups until it reaches about 55°C.
3. Add the tea leaves to the kyusu, then pour the water in slowly.
4. Wait for 2 minutes. The tea should be sweet and glowing like pale jade. Savor it in small sips.
5. For the second infusion, raise the water temperature to around 55-60°C and cut the brew time to about 30 seconds. For the third round, raise the temperature a little more and brew for 15 seconds.

Genmaicha

Leaf-to-water ratio: 10g per 240ml
Water temperature: 80-100°C
Infusion time: 1st – 30 seconds; 2nd – 10 seconds

Steps:

1. Add the tea to the teapot or kyusu.
2. Pour the hot water over the leaves and let it brew for 30 seconds without stirring.

Hojicha

Leaf-to-water ratio: 3-5g per 200ml
Water temperature: 90-100°C
Infusion time: 30 seconds - 1 minute

Steps:

1. Add the tea leaves to the teapot or kyusu.
2. Pour the hot water over the leaves and let it infuse for 30 seconds without stirring. If you'd like a stronger brew, increase this to 1 minute.

Tips for three infusions:

Japanese teas are designed to give and give again. After pouring the first infusion, slide the teapot lid slightly open. This stops the tea leaves from steaming and ensures a good second brew.

Increase the water temperature slightly for the later rounds to draw out the rest of the umami and to enjoy the astringency released at higher temperatures.

The second infusion extracts faster, so reduce the brew time dramatically - don't let the tea sit and steep.

How to Store and Revive Tea

Once opened, tea begins a slow but steady march toward dullness. To keep it lively:

• Store it in airtight containers, away from light, moisture and strong odors.
• Unopened tea can be kept in the the refrigerator but let the packet return to room temperature before opening it or condensation will ruin the leaves.
• Once opened, transfer the tea to an airtight, light-blocking container and store it in a cool, dark place. Don't put it in the refrigerator - tea absorbs odors easily and will also turn damp when taken out and put back.
• Use the leaves up within two weeks to a month after opening. Tea is not a time capsule.

If your tea has gone stale, all is not lost. To revive it, heat a clean frying pan over low heat. Add the old tea leaves - no oil, please - and roast them slowly till a toasty aroma fills the air.

What was once tired sencha has been reborn as fragrant hojicha.

Tasting Every Little Thing

Every leaf has its optimum temperature and timing. Treat it right and your cup of tea won’t just taste better - it might make the day go better too.

But brewing green tea isn’t about adjusting it to perfection. It’s about enjoying the small variables that make each cup unique because sencha will always be a little different depending on your water, your teaware and even your mood.

Remember: don't keep anything back. When pouring, pour to the very last drop and enjoy everything, from the first infusion to the final cup.

By Janice Tay