So I am on the search for a good decaf coffee due to my wife being pregnant, and while I know it's been said through the roasting process of coffee that very little if any chemicals remain from the decaffination of coffee, I am still a little skeptical. My wife and I figure that if you are going to go through the trouble of trying to avoid caffeine in your coffee, especially for pregnancy, you should probably try and avoid anything else that might be harmful in the coffee. So I am looking for decaf coffee produced either through a Swiss Water Process or CO2.
Both of these methods don't use any harmful chemicals, they use water and liquidfied CO2. Both of these are very similar in the ways that they extract the caffeine from coffee. I intend to go over just a quick view of the Swiss Water process.
As the name of the process implies, the Swiss Water Process was first discovered in Switzerland in the 1930s. For the process to be effective a coffee solution must first be made with disolved coffee solids. To do this they soak the green beans in heated water until the caffeine from the beans is leeched out, but the coffee solids come out as well (i.e. the flavor we enjoy). So they then take this caffine and solids solution and process it through carbon filters to remove the caffine but leave in the solids. This is the green coffee solution.
The next step is taking the solution and new batch of green beans that you want to decaffinate. Now due to already having coffee solids in the water when the green beans are placed in this solution and heated only the caffeine is leeched from the beans. And then the water is filtered and done again until most of the caffeine is removed from the bean. Then the green beans are dried and sent to the roasted to be roasted.
The CO2 process is essentialy the same except it's done with liquid C02 at pressue. This process is thought to be even more effective at keeping the flavors of the coffee intact through the process.
So these are the two methods I am looking at for getting decaf coffee, wish me the best and if you want to do a little futher reading you can look at Swisswater.com or the wiki page.