Brewing Tips

Last updated: August 2026

Cold brewing black tea means steeping loose leaf in cold water for 6–8 hours instead of hot water for minutes — it extracts far less tannin, producing a naturally smoother, sweeter cup with no added bitterness. Our Ruby Black Tea, grown at 5,500–7,000 ft on Sandakphu Tea Estate in Ilam, is built for it: dark cherry and cocoa notes with a velvet mouthfeel, bold but never bitter, even before cold water's gentler extraction takes effect.

If you want to try it yourself, start with our $30 Tea Sampler Kit — 10 single-origin teas from four farms in Ilam and Taplejung at 5,000–7,000 ft, including both black teas in this guide, so you can compare hot and cold brewing side by side. No bitterness, in any of them.

Why Does Cold Brewing Remove Bitterness From Black Tea?

Cold brewing removes bitterness because tannins and caffeine extract far more slowly in cold water than in hot water. A study on the extraction kinetics of black tea found that phytochemical release follows temperature-driven diffusion — in hot water, molecules move quickly across the leaf's cell walls, pulling out tannins and caffeine fast; in cold water, that diffusion slows dramatically (Extraction Kinetics of Phytochemicals During Black Tea Brewing). The result is a cup with less astringency and a gentler caffeine curve, without losing the tea's character.

For a black tea already grown to be smooth — Nepal's high-altitude leaf develops naturally lower tannin levels than lowland tea to begin with — cold brewing amplifies that softness rather than creating it from scratch. "Ruby Black already drinks bold without any harshness," says Bhaskar Dahal, founder of Nepal Hills Tea. "Cold brew it overnight and what you get is almost dessert-like — dark cherry and cocoa with none of the bite people expect from a strong black tea."

Which Nepal Hills Black Teas Cold Brew Best?

Both of our single-origin black teas cold brew well, but they produce different cups. Ruby Black Tea, from Sandakphu Tea Estate at 5,500–7,000 ft in Ilam (grown on a certified organic farm), is the bolder choice — dark cherry, cocoa, and a velvet mouthfeel that holds up even at cold-water strength. It's the tea we recommend to coffee drinkers switching to tea, since cold brewing gives it an almost espresso-like body without bitterness. Gold Black Tea, from Farmers Tea Co. in Malate, Ilam at 5,500 ft (also grown on a certified organic farm), is the gentler option — smooth malt, light caramel, and honey sweetness with visible golden tips, closer to a cold-brewed everyday breakfast tea.

How Do You Cold Brew Loose Leaf Black Tea?

Cold brewing black tea is hands-off once you've measured the leaf. Here's the method we use for both Ruby Black and Gold Black:

1. Measure the leaf. Use roughly 1.5–2x the loose leaf you'd use for hot brewing — about 2 level teaspoons (4–5g) of Ruby Black or Gold Black per 250ml of cold water, since cold extraction pulls out less flavour per gram.
2. Use cold, filtered water. Room-temperature or refrigerator-cold filtered water both work; chlorinated tap water can dull the fruit and malt notes.
3. Steep in the fridge for 6–8 hours. A mason jar or any covered pitcher works. Steep overnight if it's easier — black tea is forgiving and won't turn bitter the way it can with a hot over-steep.
4. Strain the leaves. Pour through a fine mesh strainer or remove your infuser basket.
5. Serve over ice. Cold brew concentrate holds its flavour well; pour straight over ice, or dilute slightly if you prefer a lighter cup.

Ruby Black vs. Gold Black Cold Brew: Which Should You Choose?

If you want a bold, espresso-adjacent iced tea with dark fruit and cocoa depth, Ruby Black Tea is the better cold brew. If you want something closer to a classic iced breakfast tea — smooth, lightly sweet, easy to drink all afternoon — Gold Black Tea is the gentler choice. Both are naturally free of bitterness, grown on certified organic farms in Ilam, and cold brew without the guesswork hot brewing sometimes requires.

Where to Start — The Tea Sampler Kit

Not sure which to try first? The Nepal Hills Tea Sampler Kit ($30 CAD) includes 5g each of Ruby Black and Gold Black Tea alongside eight other single-origin teas from Ilam and Taplejung — enough to cold brew a small batch of each and compare directly, no bitterness in any of them, free returns if it's not for you.

Written by: Bhaskar Dahal, Founder and CEO, Nepal Hills Tea Inc.

Frequently Asked Questions

Can you cold brew black tea?

Yes. Black tea cold brews very well — the slower extraction in cold water pulls out less tannin and caffeine than hot brewing, producing a smoother, naturally sweeter cup. Ruby Black Tea and Gold Black Tea, both grown on certified organic farms in Ilam at 5,500+ ft, are well suited to it.

How long should black tea steep in cold water?

6–8 hours in the refrigerator, or overnight for convenience. Black tea is forgiving in cold water — unlike hot brewing, leaving it an extra hour or two won't make it bitter.

What's the tea-to-water ratio for cold brew black tea?

Use about 1.5–2x the leaf you'd use hot — roughly 4–5g (2 level teaspoons) of loose leaf per 250ml of cold water. Cold water extracts less flavour per gram, so a bit more leaf keeps the cup from tasting thin.

Does cold brew black tea have less caffeine?

Generally, yes. Caffeine extraction is temperature-dependent and slows in cold water, so a cold brew steeped for the same or even longer time typically yields less caffeine per cup than a hot-brewed cup of the same tea.

Can I use the same black tea for hot and cold brewing?

Yes — Ruby Black Tea and Gold Black Tea both work hot or cold. Hot brewing (90–95C, 3–4 minutes) brings out more boldness and warmth; cold brewing softens the same tea into a smoother, more refreshing cup.

Is Ruby Black Tea good for cold brew?

Yes — Ruby Black Tea's dark cherry, cocoa, and velvet mouthfeel hold up especially well cold, giving it an almost espresso-like body without any bitterness. It's a good choice for coffee drinkers trying cold brew tea for the first time.

Related Reading

• How to Make Cold Brew White Tea: A Smooth & Refreshing Guide
• How to Make the Perfect Cup of Black Tea: Temperature, Time & Brewing Tips
• Cold Brew Tea Guide: How to Make Smooth, Refreshing Tea at Home