The Swiss Water Process: A Chemical-Free Method of Coffee Decaffeination

1. Overview

The Swiss Water® Process is a 100% chemical-free, water-based method of decaffeinating coffee, known for preserving flavor while removing 99.9% of caffeine from green coffee beans. It is particularly favored in the specialty coffee industry for its clean process, traceability, and ability to retain a coffee’s origin characteristics. Unlike solvent-based decaffeination methods, the Swiss Water Process relies on osmosis and solubility science rather than chemical solvents like methylene chloride or ethyl acetate.

2. Origin and Background

The process was originally developed in Switzerland in the 1930s but was later commercialized and refined in British Columbia, Canada, where Swiss Water Decaffeinated Coffee Inc. began operations in the 1980s. Today, all Swiss Water Process decaffeination is done at their facility in Burnaby, BC.

The company works exclusively with certified organic and specialty-grade coffees, and the Swiss Water® brand is trademarked to distinguish it from other water-based methods.

3. How the Swiss Water Process Works

The Swiss Water Process operates through a four-stage cycle, using only water, temperature, and time to remove caffeine:

Step 1: Green Coffee Extract (GCE) Creation
A Green Coffee Extract (GCE) is created by soaking a batch of green coffee beans in hot water to dissolve the soluble compounds—caffeine, sugars, acids, and aromatic compounds.
The water is then passed through a carbon filter that removes only the caffeine.
The resulting liquid (now caffeine-free but still rich in flavor compounds) becomes the base for decaffeinating future batches.
Step 2: Caffeine Removal by Osmosis
A new batch of green (caffeinated) coffee is soaked in the GCE.
Because the extract already contains soluble coffee solids (excluding caffeine), only the caffeine migrates from the beans into the solution—through osmosis.
This avoids stripping the beans of their flavor, unlike solvent-based or initial water-only methods.
Step 3: Continuous Circulation and Filtration
As the caffeine moves out of the beans and into the GCE, the extract is continuously filtered through carbon filters to trap caffeine molecules.
The GCE is recycled and reused across batches, maintaining consistent flavor-preserving properties.
Step 4: Drying and Preparation
Once caffeine content is reduced to 0.01% or lower (99.9% caffeine-free), the beans are dried, bagged, and labeled.
Coffees are often roasted to order by specialty roasters and labeled as Swiss Water Process Decaf.
4. Scientific Principles

The Swiss Water Process relies on two primary scientific mechanisms:

Osmotic Gradient: Solutes (caffeine molecules) naturally move from areas of high concentration (inside the bean) to low concentration (in the GCE) until equilibrium is achieved.
Carbon Filtration: A proprietary, activated carbon filter is used to trap caffeine while allowing other soluble flavor compounds to remain in solution.
Because no solvents are used, and because the solubility equilibrium is tightly controlled, the process is able to maintain much of the bean's flavor complexity and chemical integrity.

5. Flavor Preservation and Quality

Swiss Water Process decafs are praised for their ability to retain origin character and clarity, even when brewed next to their caffeinated counterparts. While any decaffeination process alters a bean’s chemistry slightly, this method minimizes degradation of key flavor attributes like:

Acidity
Body
Aromatic complexity
Balance
Swiss Water decafs often feature clean, sweet profiles with gentle acidity and medium body—ideal for espresso, filter, or even cold brew applications.

6. Sustainability and Certifications

Swiss Water Decaffeinated Coffee Inc. is committed to sustainability and traceability. The process is:

100% solvent-free
Certified organic (by USDA and other agencies)
Kosher, Halal, and non-GMO certified
Climate-responsible, with water filtration systems and carbon tracking in place
Swiss Water also offers Origin Select Decaf and Custom Process Decaf, allowing roasters to decaffeinate microlots or exclusive offerings with full traceability.

The Swiss Water Process represents a best-in-class method for producing high-quality, decaffeinated coffee without the use of chemicals. By preserving flavor, offering full traceability, and promoting environmental sustainability, it has become a gold standard in the specialty coffee world. For roasters, baristas, and consumers who demand clean, ethical, and delicious decaf—Swiss Water delivers a compelling solution.