What? There’s corn in coffee???! Hell yeah there is. Sorry. I tolerated any old coffee (except the flavors, which are mostly corn) for many years, but it was one of the first things I started reacting to when I got more sensitive.
Here’s how it gets corny:
- Bean fermentation/processing: “Wet process” coffee introduces a ton of opportunities for corn-tamination, not the least of which being fermentation of the beans which could involve microbes that have been fed corn-derived sugar or possibly–and this is just a speculation as I don’t know the details– even some additional corn sugar to the beans to encourage the microbes to grow. Additionally there are all kinds of machines and washes used along the way for wet processing that could introduce at least cross-contamination if not full on corn.
- Roasting: Corn-derived disinfectants, flavorings, or preservatives may be added to the beans before roasting.
- Polishing: The beans may be polished with dextrins (from corn) to make them shiny.
- Decaffeination: Chemicals used in the decaffeination process are corn-derived. There is a chemical-free process called the Swiss Water Process that isn’t really corn-safe even for the medium-sensitive, but it at least reduces the danger of cross contamination of the caffeinated coffee.
- Cross-contamination: Shared facilities/equipment with coffee that is chemically decaffeinated or flavored can contaminate the caffeinated/unflavored coffee beans. Additionally burlap bags are often re-used and you will sometimes find whole kernels of corn in with the coffee beans. Roasting equipment and facilities may be cleaned with corny chemicals, or may be shared with other food items besides coffee.
- Brewing: Paper coffee filters will often be corntaminated, even the unbleached organic kind. Stick with reusable filters. Reusable filters could possibly be made from corny plastic or be impregnated with antimicrobials. The safest option is probably a stainless-and-glass french press.
- Packaging: Paper coffee bags are usually lined with PLA , which is a plastic made from corn starch. Ingeo is a brand name for PLA. Foil bags can be dusted with corn starch or oiled with corn oil to keep them from sticking.
This post is still in somewhat draft format as I learn more about the coffee industry. Last updated 2013-05-11 with my most current knowledge.