Teekanne double-chamber tea bag

What it is

The double-chamber tea bag is the familiar W-folded bag with two pockets of tea, a cotton string and a paper tag, closed without glue or staples. Teekanne of Düsseldorf patented it in 1949. Its sister company Teepack Spezialmaschinen builds the high-speed machines that form, fill and fold such bags, and sells them to tea packers worldwide.

How it works

A strip of filter paper is dosed with two portions of tea, folded so that each portion sits in its own chamber, and then folded again into a single bag. The string is attached by knotting or folding rather than with metal clips. With two chambers, hot water can reach the leaves from more sides, which helps the tea infuse more quickly than in a flat single bag. The first fully automatic machine for this format, Constanta, was presented by engineer and Teepack co-owner Adolf Rambold. Sources give its output as 120 (Teepack) to 160 (Teekanne) bags a minute. Its successor line, Perfecta, reaches around 400.

Why it stands out

The invention lives far beyond the Teekanne brand. Teepack describes itself as world market leader in its field and says it has delivered more than 3,000 double-chamber packing machines to over 50 countries. That means many of the double-chamber bags sold under other names, in other countries, come off German-designed machines. Rambold had earlier built the Pompadour machine of 1929, which produced 35 gauze tea bags a minute.

Where you meet it

In kitchens, hotel rooms and offices across Europe, the Middle East and beyond. Teekanne itself, according to Wikipedia, packs about 7.5 billion tea bags a year, much of it at its Düsseldorf plant, while Teepack machines run in tea factories on several continents.

Sources

• Teekanne: History
• Teepack: Company
• Wikipedia: Adolf Rambold
• Wikipedia: Teekanne