Cold-Brew Green Tea in a Plastic Bottle

What is cold-brew green tea

Cold-brew green tea is steeped in cold water over several hours instead of hot water. Compared to hot-brewed tea, bitterness and astringency are subdued while sweetness and umami stand out.

A plastic bottle is all you need, making it perfect for hot days in HCMC.

Why cold brew tastes great

Green tea flavor comes from theanine (umami), caffeine (bitterness), and catechin (astringency).

Caffeine and catechin dissolve more at high temperatures, while theanine extracts well even in cold water. Cold brew thus reduces bitterness and astringency while highlighting sweetness and umami.

Lower caffeine content makes it suitable for those sensitive to caffeine, children, or evening drinking.

Making it in a plastic bottle

What you need

• Clean plastic bottle (500ml)
• Green tea leaves: about 5-6g (1 tablespoon)
• Cold or room-temperature water: 500ml
• Tea filter bag (non-woven fabric)

Steps

1. Put tea leaves in a filter bag

Place tea leaves in a filter bag for easy straining. Without a bag, add leaves directly and strain when pouring.

2. Place in bottle and add water

Drop the tea bag into the bottle and fill with cold water. Room-temp water works but cold water gives a crisper finish.

3. Refrigerate 3-8 hours

Seal tightly and refrigerate. Steeping times:

• 3-4 hours: Light, refreshing flavor
• 6-8 hours: Rich umami and sweetness
• Overnight (8+ hours): Full-bodied. Some astringency may emerge

Set up at night, ready by morning: the easiest approach.

4. Remove tea leaves. Done.

Take out the tea bag once it reaches your preferred strength. Leaving it too long adds astringency.

Choosing tea leaves

The right tea leaves make a difference.

• Fukamushi-cha (deep-steamed): Longer steaming makes extraction easier in cold water, smooth result
• Gyokuro: Rich in theanine, cold brew yields luxurious sweetness
• Sencha: Most standard, clean and refreshing
• Cold-brew tea bags: Most convenient for beginners

Compared to hot-brewed tea

	Cold brew	Hot brewed
Sweetness/umami	Strong	Moderate
Bitterness/astringency	Mild	Pronounced
Aroma	Subtle	Vibrant
Caffeine	Low	High
Color	Pale yellow-green	Deep green
Extraction time	3-8 hours	1-2 minutes

Neither is better; each has its strengths. Cold brew for hot weather, hot brew for cold days or relaxation.

Health benefits

Cold-brew green tea offers several health advantages.

• Theanine for relaxation: Known for promoting calm
• Low caffeine: Cold extraction reduces caffeine content
• Hydration: A flavorful alternative when plain water isn't enough
• Epigallocatechin: A catechin that extracts well at low temperatures, supports immune function

Cold brew green tea for HCMC's heat

HCMC is hot year-round and cold drinks are essential. Instead of sugary bottled drinks, keeping cold-brew green tea on hand provides sugar-free hydration.

Prep the night before, enjoy in the morning. Take it to the office or on the go.

Storage tips

• Keep finished cold brew refrigerated, drink within 24 hours
• Leaving leaves in too long causes astringency and spoilage
• Wash the bottle thoroughly each time

Summary

With just a plastic bottle and tea leaves, anyone can make cold-brew green tea. Mellow sweetness and clean flavor: perfect for HCMC's hot days.

Download the Farmi app and find your favorite Japanese tea.

Note: This article and some images were created with the assistance of AI (artificial intelligence) and reviewed by the editorial team before publication.