Why Does Decaf Coffee Taste Bad?

Drinkers of regular coffee know that when they try a cup of decaf that more than just the caffeine is missing. The problem is removing caffeine while retaining the many chemicals that give coffee its aroma, flavor and health benefits. Different processes produce different results. Coffee Confidential explains what all decaf processes have in common in their article about four ways to decaffeinate coffee.

Coffee is always decaffeinated in its green (unroasted) state.

The greatest challenge is to try to separate only the caffeine from the coffee beans while leaving the other chemicals at their original concentrations. This is not easy since coffee contains somewhere around 1,000 chemicals that are important to the taste and aroma of this wonderfully complex elixir.

Since caffeine is a water-soluble substance, water is used in all forms of decaffeination.

However, water by itself is not the best solution for decaffeination. Water is not a “selective” solvent and therefore removes other soluble substances, like sugars and proteins, as well as caffeine. Therefore all decaffeination processes use a decaffeinating agent (such as methylene chloride, activated charcoal, CO2, or ethyl acetate). These agents help speed up the process and minimize the “washed-out” effects that water alone would have on the taste of decaf coffee.

It is because of the varying degrees of success in removing caffeine and not everything else that decaf coffee often tastes bad.

The four basic processes for decaffeination are these:

  • Indirect-Solvent Process
  • Direct-Solvent Process
  • Swiss Water Process
  • Carbon Dioxide Process

Currently the only solvents used in decaffeination are methylene chloride and ethyl acetate.

Indirect Solvent Process

  • Soak green beans in water for several hours to extract caffeine, oils and flavor elements
  • Remove water to another tank and wash beans for ten hours with solvent
  • Heat to evaporate solvent bonded to caffeine
  • Put beans back in the water to reabsorb oils and flavor elements

Direct Solvent Process

  • Steam green beans for 30 minutes
  • Rinse with solvent for ten hours
  • Drain solvent and steam beans to further remove solvent

Swiss Water Process

  • Soak green beans in very hot water
  • Draw off water and pass through an activated charcoal filter with porosity set to catch caffeine and not smaller oil and flavor molecules
  • Discard beans that have no caffeine and no flavor
  • Use water rich in oil and flavor to watch next batch of green beans

Carbon Dioxide Process

Green coffee beans are soaked and placed in a stainless steel extraction tank

  • The tank is sealed and liquid CO2 is forced into the tank at 1000 pounds per square inch pressure
  • CO2 absorbs caffeine
  • CO2 is removed and pressure is released allowing C02 to escape free of caffeine.
  • CO2 can then be reused for subsequent batches of coffee.

Difficult to Roast

So, why does decaf coffee taste bad? First of all it is difficult to remove caffeine and not the flavor and aroma from green coffee beans. Second it is harder to roast decaffeinated beans and get a good result. The beans roast faster because of lower bound moisture content. Also decaf beans are almost brown and respond variably to roasting.

In the end if you want a really good cup of coffee stick with organic coffee from Colombia or another top level coffee. And if you want less caffeine, drink a little less coffee!

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