Full disclosure: I’m a caffeine junkie. I’m on my second cup of coffee as I’m writing this, at 8:38 in the morning, and will drink many more before the day is through.

But when a reader (okay, my mom) asked me about the most eco-friendly way to decaffeinate a coffee bean or tea leaf, I did a bit of research and found it interesting enough to want to share.

As seems to be the norm, the healthiest options for the planet are also the healthiest for our bodies.

1. The Original Gold Standard: Swiss Water Process

This method was developed in Switzerland in the 1930s as an effort to decaffeinate coffee beans without harmful solvents. Here’s how it works:

• Green Bean Swelling: Green coffee beans are soaked in hot water, which causes them to expand and release their caffeine and flavour compounds into that water.
• Filtration: The water is passed through a carbon filter, which captures the caffeine molecules while allowing the flavour compounds to flow through. The filtered water, minus the caffeine but with all the natural flavour, is called green coffee extract, or GCE.
• New Beans Soaking: A new batch of beans is immersed into the green coffee extract. Because it’s already saturated with flavour, only the caffeine escapes from the beans, so this batch of beans ends up decaffeinated but full of flavour.

Eco Footprint: The Swiss Water Process recycles 85% of its water, and reuses the carbon filter and green coffee extract for batch after batch of new beans. It’s chemical-free, which allows organic coffee beans to keep their organic stamp even after being decaffeinated by this process.

2. The Worst: Methylene Chloride

This method, using an ingredient often found in paint stripper, is widely used by large commercial brands (Starbucks, Kirkland, Maxwell House, etc.) for both coffee beans and tea leaves.

Green coffee beans are soaked in methylene chloride, which bonds with the caffeine to remove it from the bean. In theory, all the chemicals are evaporated off in the rinsing and drying, leaving the coffee bean with most of its original flavour.

Eco Footprint and Human Health: Most uses of methylene chloride have been banned by the United States Environmental Protection Agency, cited by the Biden-Harris administration as a “dangerous chemical known to cause liver cancer, lung cancer, breast cancer, brain cancer, cancer of the blood, and cancer of the central nervous system, as well as neurotoxicity, liver harm and even death.” Although the amounts remaining in decaffeinated coffee are typically trace if any, I would personally run in the other direction when literally every other decaffeination method is safer.

3. The Maybe: Ethyl Acetate Method

Ethyl acetate is a naturally occurring compound found in fruits. The jury is mixed about whether this method is natural and healthy, or if it’s a harmful chemical to avoid.

It’s also known as the sugarcane method because the ethyl acetate used for decaffeination is usually derived from sugarcane molasses by fermentation.

The process is nearly identical to methylene chloride, but with a chemical that is a definite step up from paint remover.

• Soaking: Green coffee beans are soaked in a solution of ethyl acetate and water, allowing the caffeine to bond with the solvent and separate from the plant material.
• Washing: The mixture is washed to remove the ethyl acetate, retaining a rich flavor profile without the caffeine.
• Final Steam and Drying: The beans are dried at a higher temperature than the boiling point of ethyl acetate, which allows any remaining ethyl acetate to evaporate.

Eco Footprint: It’s a great option for coffee beans that are grown near sugar cane farms, because it’s a simple process that takes away the need to transport the beans to be decaffeinated elsewhere. Some direct trade roasters whose ethos I generally like (like Pilot Coffee and 49th Parallel) favour this method and sell it as eco-friendly.

Human Health: Not the worst. Not the best. Ethyl acetate is considered harmful in large amounts, but the trace amounts that might end up in the decaf beans don’t alarm me. If you’re drinking a lot of decaf and want the healthiest option, I’d probably avoid this method too.

4. Fancy Good Option: Supercritical CO2 Process

This innovative method doesn’t involve giving coffee beans and tea leaves to your mother-in-law. In this case, supercritical is a chemistry term to mean a substance is at a temperature and pressure that can’t be classified as a liquid, solid, or gas.

In this state, the carbon dioxide selectively extracts caffeine from coffee beans and tea leaves, while leaving most of the natural flavours and oils inside.

The caffeine that’s taken out is often not wasted, but sold to companies that make energy drinks, pharmaceuticals, and cosmetics.

This is touted as an eco-friendly method that preserves the most flavour. It’s often used by specialty, direct trade coffee roasters who are willing to travel the world to bring back the best tasting beans. (One might even call them supercritical.)

Eco-Footprint: This is a high-tech solution with minimal waste, and very eco-friendly. The only chemical used is carbon dioxide, which is naturally occurring and adds no risk to the beans and leaves.

5. Herbal Alternatives

Want to avoid caffeine and slash your carbon footprint altogether? Why not grow your own tea garden? Whether you have a patch of soil outdoors or a countertop hydroponic system, many herbs can be dried and enjoyed in a cup of tea.

We’ve just ordered a collection of mint, chamomile, lemongrass, and a couple more. West Coast Seeds has a Tea Garden Collection to get your creative juices flowing.

Which Method Does My Brand Use?

Since it’s not mandated for companies to disclose their decaffeination method on the label, a good bet is that if it is one of the good ones (Swiss Water or CO2), they’ll print that. If you don’t see a method, it’s likely methylene chloride.

Some direct trade companies — like 49th Parallel — use different methods for different roasts, because they’re so exacting about the flavours they’re trying to create.

Some common brands and their decaffeination methods:

Swiss Water Process (the original gold standard)

• illy
• Allegro Coffee
• David’s Tea
• Tim Hortons
• Kicking Horse Coffee
• Puro Coffee
• 49th Parallel (Swiss Water blend)
• Nescafe

Methylene Chloride (the worst)

• Starbucks
• Kirkland
• Maxwell House
• Folgers
• Yorkshire Tea

Ethyl Acetate Method (the maybe)

• Pilot Coffee
• Peet’s Coffee
• Tetley tea (which I stopped drinking because of the microplastic in it!)
• Twinings Tea
• Lipton Tea
• Café Altura
• 49th Parallel (Columbia Magdalena)

Supercritical CO2 Process (the new best?)

• Blue Bottle Coffee
• Stumptown Coffee Roasters
• Intelligentsia Coffee
• Nespresso
• Celestial Seasonings Tea
• Stash Tea
• Clipper Tea

Is the brand you drink not on this list? There’s a site called “Check Your Decaf” that might be able to help.