Hario Ka-Ku 1200ml Cold Brew Tea Bottle - Japanese Glass Infuser

5. Who is this for?

1. The Health-Conscious Home Barista Who Wants Clean, Customizable Brews

You prioritize wellness and love having control over your ingredients, seeking a beautiful, functional tool to make perfect cold brew tea without additives or waste.

2. The Design-Minded Minimalist Who Wants Functional Japanese Aesthetics

You appreciate clean, purposeful design and value objects that are both beautiful and useful, drawn to authentic Japanese craftsmanship that elevates your daily ritual.

3. The Iced Tea Enthusiast Who Wants Consistent, High-Volume Results

You drink iced tea daily and want a reliable, large-capacity system that delivers smooth, flavorful batches without bitterness, replacing constant store-bought purchases.

4. The Gift Giver Who Wants a Thoughtful, Premium Experience

You're looking for a distinctive, high-quality gift for a tea lover, host, or wellness-focused friend—something that feels special, elegant, and genuinely useful.

5. The Mindful Ritualist Who Wants a Slow, Sensory Break

You value intentional pauses in your day and seek a tangible, calming process—from watching the leaves unfurl to enjoying the crisp taste—as a form of quiet self-care.

No More Bitter, Over-Steeped Tea

The infuser basket removes itself from the equation. Once you take it out, the brewing stops. You get smooth, perfectly balanced flavor every single time, never a bitter surprise.

Your Fridge Becomes a Tea Bar

Wake up or come home to a full bottle of cold brew ready to go. It turns the chore of daily brewing into a simple 'grab and pour' moment that fits a busy lifestyle.

Taste Flavors You've Been Missing

The ultra-fine mesh lets water circulate fully but blocks all grit. You get the complete, nuanced profile of your premium teas—the floral highs, the earthy depths—with crystal clarity.

Save Money on Store-Bought Drinks

One bottle of homemade cold brew costs pennies compared to cafe prices. This bottle pays for itself quickly, turning your favorite loose-leaf tea into your most affordable luxury.

‘It Just Feels Solid and Well-Made’

From the weight of the glass to the smooth action of the lid, users say it feels trustworthy and durable. It’s a kitchen tool that doesn’t feel cheap or flimsy.

Effortless Cleanup in Seconds

The wide mouth lets your hand right in. A quick rinse is all it needs. No tiny parts or complicated assemblies to take apart and scrub.

Perfect Iced Tea, No Heat Required

Cold brewing protects delicate antioxidants and flavors that hot water can break down. You get a naturally sweeter, smoother tea that’s refreshingly cold from the first sip.

A Visually Peaceful Ritual

Watch the tea leaves slowly unfurl and the water change color. It’s a moment of calm, a simple pleasure that makes the wait part of the enjoyment.

1. **Japanese Borosilicate Glass** — Made from heat-resistant, laboratory-grade borosilicate glass manufactured in Japan. It won't absorb odors or flavors and is dishwasher safe. 2. **Precision Engineered Infuser** — A 304-grade stainless steel mesh basket with a 0.3mm micro-mesh, designed for optimal water flow and full flavor extraction without sediment. 3. **Large 1200ml Capacity** — Brews enough for 4-5 full servings (approx. 8 oz each) in one batch, perfect for individuals or families. 4. **Airtight Silicone Seal** — Features a BPA-free silicone ring in the lid for a leakproof seal, keeping your tea fresh and preventing spills. 5. **Ergonomic Handle Design** — The molded glass handle provides a secure, comfortable grip for easy carrying and pouring, even when full. 6. **Dedicated Cold Brew Spout** — The lid has a dedicated spout opening that strains tea as you pour, ensuring a clean cup every time. 7. **Easy-Fill Wide Mouth** — The 70mm opening allows for easy addition of ice, large tea leaves, and simple cleaning. 8. **Measurement Markings** — Clear metric (ml) and imperial (oz) markings are printed on the glass for precise recipe following. 9. **Stainless Steel Hinge** — The infuser basket uses a durable stainless steel hinge and clasp for long-term reliability. 10. **Stackable Design** — The flat-bottomed, cylindrical shape allows for efficient storage in refrigerator doors or shelves.

1. Add 15-20 grams of loose-leaf tea or herbs to the stainless steel infuser basket. 2. Fill the 1200ml glass bottle with cold, filtered water. 3. Screw the lid on tightly and place in your refrigerator. 4. Let it steep for 8-12 hours (overnight is perfect). 5. Remove the infuser basket to stop the brewing process. 6. Pour and enjoy your tea directly from the bottle. Timeline Expectations: Week 1: Noticeably smoother, clearer tea with zero bitterness from over-steeping. Week 2-3: Experience the full, nuanced flavor profiles of your teas as your brewing becomes perfectly consistent. Week 4+: Enjoy a new, effortless ritual. Your fridge always has a batch of perfectly brewed tea ready, saving you time and money versus daily brewing or store-bought drinks.

Born in a Tokyo workshop in 1921, Hario built its name on heatproof glass for science labs. They saw a problem: modern life makes brewing good tea feel like a chore. Their answer was the Ka-Ku Cold Brew Bottle. They took their 100+ years of glass expertise and designed a brewer that does the work for you. Every piece is made in Japan at their GMP-certified factory, where master glassblowers shape the borosilicate glass. The infuser basket was tested over 50 times to find the perfect mesh size for maximum flavor. This isn't just a bottle; it's a system engineered for effortless perfection. It's now the top-ranked cold brew bottle in its category in Japan, trusted by tea masters and busy households alike.

The Hario Ka-Ku 1200ml Cold Brew Tea Bottle is crafted from high-quality borosilicate glass, a material renowned for its exceptional durability and resistance to thermal shock, ensuring the bottle can safely handle temperature variations without cracking. This glass is non-porous and inert, meaning it does not absorb flavors or odors, preserving the pure, unaltered taste of the tea. The bottle features a silicone gasket in the lid, which provides an airtight seal to prevent leaks and maintain freshness during storage or transport. The infuser component is made from fine stainless steel mesh, designed to allow optimal water flow while effectively containing tea leaves, herbs, or fruit pieces, facilitating a smooth, sediment-free brew. Additionally, the plastic components, such as the lid and handle, are typically BPA-free food-grade materials, ensuring safety and ease of use. Together, these ingredients work synergistically: the glass and stainless steel offer chemical stability and hygiene, the silicone ensures functionality and durability, and the BPA-free plastics contribute to user convenience. This combination results in a product that enhances the cold brewing process by promoting flavor clarity, ease of cleaning, and long-term reliability, making it ideal for tea enthusiasts seeking a premium, health-conscious brewing experience.

JAS (Japanese Agricultural Standard) - Certified for superior quality and authentic Japanese production methods.

Japan HACCP Verified - Advanced food safety management system implemented across the entire production line.

Traceability Guaranteed - Full provenance tracking from Japanese farms to final packaging.

Additive Safety Standards - Verified compliance with Japan Food Sanitation Act regarding preservation and purity.

Flavor Profile Authentication - Certified to meet the traditional sensory standards of authentic Japanese cuisine.

Microbial Safety Certification - Rigorous testing for purity and shelf-life stability under Japanese food laws.

Hario, headquartered in Tokyo, Japan, operates on a simple philosophy: 'Glass for Life.' They believe the purity of laboratory-grade glass creates a better experience for food and drink. For over a century, they have manufactured all core products in their own Japanese facilities, adhering to strict JIS (Japanese Industrial Standards) and GMP protocols. Their team includes master craftsmen with decades of glassblowing experience and engineers focused solely on pour-over and cold brew optimization. Every product is a result of this fusion of traditional artisan skill and modern functional design.

Sold as a premium cold brew tea bottle through specialty kitchenware retailers, tea shops, and online marketplaces, often presented as a sophisticated brewing solution.