How Does Bigelow Decaffeinate Its Green Tea?

Bigelow answers this directly on its site: “In the case of green tea, we use the carbon dioxide (CO2) process.” Its black teas go through a different method, using ethyl acetate. Bigelow says it picks each process to protect the flavor of that type of tea.

How does Bigelow’s CO2 process work?

Bigelow describes the steps this way:

1. The tea leaves are moistened with water.
2. They’re treated with heat and pressure.
3. CO2 is introduced and binds to the caffeine in the leaves.
4. The caffeine is separated from the leaves through evaporation.

Bigelow says no CO2 remains in the leaves afterward. It doesn’t publish the temperature, pressure or time it uses. Scientists call the general method supercritical CO2 extraction. Under the right pressure and temperature, CO2 acts like a solvent that can pull out specific compounds.

Is Bigelow decaf green tea water processed?

Not by Bigelow’s description. Water moistens the leaves, but CO2 is what removes the caffeine.

The term “water process” usually refers to something else. It describes soaking coffee beans in hot water to wash out caffeine, then using a carbon filter to remove it from the water. Bigelow names no such step for its green tea.

What are the common decaf methods?

Method	How it works	Where it’s used
CO2	Pressurized CO2 draws caffeine out of moistened leaves	Bigelow’s green teas, and widely used for decaf tea
Ethyl acetate	Moistened leaves are treated with a solvent, which evaporates with the caffeine	Bigelow’s black teas. FDA rules allow it for decaffeinating coffee and tea
Methylene chloride	A solvent extracts the caffeine	FDA rules cap the residue at 10 ppm in decaf coffee. That provision names coffee, not tea
Water process	Hot water removes caffeine, and a carbon filter takes it out of the water	Described for coffee beans

Bigelow notes that ethyl acetate occurs naturally in tea leaves, at 5 to 20 ppm, and says its process leaves about the same level as in the original leaf. That’s Bigelow’s own statement.

How much caffeine is left in Bigelow decaf green tea?

Bigelow lists these figures per 8 oz cup:

Tea	Caffeine
Bigelow green tea	25 to 50 mg
Bigelow decaf tea	1 to 8 mg

That decaf range covers Bigelow’s decaf teas as a group. Its caffeine guide names Green Tea Decaffeinated in that row, but we found no separate figure for that box.

Bigelow’s FAQ also says decaffeination removes about 99.6% of the caffeine on average. That doesn’t quite match the 1 to 8 mg range, since removing 99.6% from a 25 to 50 mg cup would leave well under 1 mg. Bigelow doesn’t explain the gap, so we’d plan around 1 to 8 mg.

Does decaffeination remove EGCG?

Bigelow says there will be minimal loss of antioxidant benefits in its green decaf teas and that its CO2 process retains most of the polyphenols, a group that includes EGCG. It doesn’t publish numbers.

Independent studies show results that depend heavily on the conditions. None of them tested Bigelow’s tea:

• A 2022 lab study removed 98.2% of the caffeine from ground green tea with supercritical CO2, and EGCG fell by 90.9%.
• That paper also cites other results. One removed 97.4% of the caffeine with a 62.2% loss of EGCG. Another removed 95.6% with a 19.8% loss of catechins.
• A 2003 UCLA study found 21.2 to 103.2 mg of total flavanols per gram in regular teas and 4.6 to 39.0 mg per gram in decaf teas. The abstract doesn’t separate green tea from other types.

So some loss is likely, but we found no published figure for Bigelow’s own process. For more on what affects these compounds, see which green teas measure highest in EGCG.

Is decaf green tea safe?

Bigelow calls both of its methods safe, and FDA rules allow ethyl acetate for this use. The National Center for Complementary and Integrative Health reports no safety concerns for green tea as a drink for adults.

Decaf still has some caffeine. If you’re avoiding it during pregnancy or for a medical reason, ask your healthcare provider, or choose an herbal tea. If you’re comparing brands, here’s how Twinings’ decaf green tea stacks up.