Once you have our great coffee in your possession, what can you do to help the coffee retain its precious flavor? In this blog, I’ll outline the steps you can take to help preserve flavor, while also discussing some coffee history along the way.
For a long time, coffee roasters have been faced with the problem of how to prevent freshly roasted coffee from getting stale before it gets to the consumer, because they knew that above all else, freshness is the key to a great cup of coffee. “Your goal is to preserve the maximum possible amount of the hundreds of fragrant compounds created during roasting, because they’re what give life to coffee” (Kummer, 52).
The Challenges of Coffee Packaging and Storage
In the late 19th century and most of the early 20th century, tin coffee cans were ubiquitous...the main method of storing roasted coffee.
While coffee cans have a certain nostalgia to them, it might be the least effective storage method to preserve freshness. The four culprits to stale coffee are air (oxygen), heat, light and moisture.
The majority of canned coffee is pre-ground. The act of grinding coffee breaks down the roasted bean’s cellular walls, releasing aromatic compounds into the air. Think of this as the coffee flavor escaping into the atmosphere. On top of that, the newly ground coffee begins to take in air and moisture. Finally, when the can is sealed, it’s rarely full of coffee, so a top layer of oxygen is sealed in with the ground coffee. This virtually ensures that the coffee is “well on the road to staleness by the time the buyer opens the can” (Kummer, 52).
There was a great leap forward in 1900, when the Hills Brothers (one of the largest roasting companies in the United States at the time) signed a contract to use the new vacuum-packing technology developed by the Norton Brothers company. “The original Hills Brothers vacuum pack bore the exaggerated claim that its Highest Grade Java and Mocha Coffee would ‘Keep Fresh Forever If Seal Is Unbroken.’ Though this claim wasn’t true, vacuum packing did improve the quality and freshness of the product” (Pendergrast, 118). But vacuum-packing wasn’t a panacea in the coffee packaging realm. “The term ‘vacuum-packed’ is misleading, because when a vacuum is used to remove air, it removes only 90 percent of it. The 2 percent oxygen left in the can is more than sufficient to stale the coffee, even if staling takes place much more slowly than it would in an open container, as Michael Sivetz of Corvallis, Oregon, a master of coffee technology explains” (Kummer, 53).
The next major innovation in coffee packaging arrived in the 1950s, out of Germany. In this method, called ‘brick-packs’, coffee is tightly shrink-wrapped, with the main advantages being that they save on the cost of metal cans and can be stored easier.
While brick packs contain less oxygen than cans, oxygen is still packed in. But the biggest disadvantage is its inconvenience. Once you open these packs, there is no easy way to re-seal it shut. “They aren’t resealable, the way cans are, so the easiest way to store what remains is just to let the open bag sit on the counter - about as bad a way as there is to keep coffee” (Kummer, 54).
Quite possibly the biggest breakthrough came in the 1960s, with the advent of the one-way valve lock bags. Valve-lock bags are those plastic bags with a small circular indentation, usually on the front of the packaging. The Italian inventor responsible was Luigi Goglio, who solved the longstanding problem of how to let coffee de-gas (release the built-up carbon dioxide gas produced during the roasting process), while keeping out oxygen (Kummer, 55).
When it comes to locking-in freshness over long periods of time, there is no better option than valve-lock bags. But there are a few disadvantages as well, making this method less than ideal. “Many roasters subject the coffee to a vacuum before packing it into the bag, which removes some aromatics. Some of the aroma that remains escapes as the beans degas and as customers eagerly press and sniff the bags. The bags won’t give coffee an infinite shelf life, either” (Kummer, 56). There is also the environmental factor to consider as well, since most valve-lock bags are made of plastic.
The latest advances in the coffee packaging world is what’s called Modified Atmosphere Packaging (MAP). Some companies use this expensive process to substitute oxygen in the packaging for an inert gas under pressure, such as nitrogen, carbon dioxide or purified argon. The reasoning for this is that these inert gases tend to be non-reactive, as opposed to oxygen’s tendency for oxidation, which is harmful to fresh coffee. Even this method is not above reproach. Corby Kummer mentions how “critics complain that this homogenizes the taste, but the removal of oxygen does help keep the beans fresher” (Kummer, 54).
Storing Brewed Coffee
I should differentiate between storing roasted coffee vs. storing brewed coffee. Storing brewed coffee is fairly simple. There are just a few rules that must be followed. The first and most important rule; keep coffee away from burners! Many automatic drip machines have built in burners to keep the coffee warm. Corby Kummer calls burners “today’s national disgrace - the chief reason you don’t like most coffee you are served” (Kummer, 77).
The familiar glass carafes should be avoided as well. They’re poor at insulating the heat from the brewed coffee.
Instead, once the coffee is brewed, pour it right away into an opaque thermal carafe with an airtight seal. The brewed coffee will remain fresh for another 45 minutes (Kummer, 77).
Storing Roasted Coffee
Since air, heat, light and moisture turn coffee stale, you want to keep your roasted coffee in the opposite environment; dark, cool and dry, and not around other aromatic foods. This eliminates the refrigerator and pantries that have spices or other aromatic foods in them.
Keeping your coffee in the fridge is not recommended. That much is not up for debate. “Certainly, refrigeration is a bad idea. If stored in a refrigerator, beans can absorb odors; this is particularly a problem with ground coffee, which is so absorbent that it used to be recommended as a refrigerator freshener” (Kummer, 57).
The real debate is whether or not to freeze your roasted coffee. I’ve read conflicting opinions from well respected coffee industry veterans. Here is what Kevin Sinnott, author and founder of Coffee Con, wrote on the subject:
“Freezing coffee beans or grounds is controversial in the coffee industry. Adherents claim it prolongs freshness. Detractors claim coffee oils and aromas inside the beans cannot literally be frozen and that the condensation that forms on the beans as they go in and come out of the freezer cancels out any improvements. After many years of testing and analysis, I believe that freezing beans or grounds works well to give them additional shelf life - as long as they are appropriately packaged and removed” (Sinnott, 43).
Corby Kummer has another opinion. He notes that although freezing is far better than refrigeration, he believes that coffee is never the same after it has been frozen. But he does concede that he’s been “persuaded to rethink by Michael Sivetz, who in the 1950s conducted studies on storing coffee. He concluded that freezing removed fewer aromatics than other forms of storage” (Kummer, 57).
For her part, Elba believes that freezing coffee is the best way to preserve her roasted coffee. She tested this by keeping her coffee in the freezer and periodically brewing a cup every few weeks. She told me that even after a month, the coffee tasted good. And Mark Pendergrast, my unofficial coffee mentor, notes “If you have to store your beans, put them in your freezer in an airtight container (with as little air in it as possible). You can grind and brew them straight from the freezer” (Pendergrast, 388).
There have been great strides in the long battle for preserving a freshly roasted batch of coffee, yet even today “because every kind of package, no matter how high the technology, comes with its own tradeoffs, there’s still no better way to buy beans than whole, roasted in the past week, stored away from air and light and heat, and packed simply in a greaseproof paper or plastic bag that can be tightly re-sealed” (Kummer, 52). This is exactly how we package and sell our coffee. We use paper bags (with an inner greaseproof lining), not only because it's cheaper than plastic bags, but because it is also environmentally friendly, and we believe it looks better.
From our perspective, why would you want to keep our freshly roasted coffee for longer than a few weeks? Once you try our coffee, we can almost guarantee that it won’t last long, so stale coffee shouldn’t be a problem for you. If you drink our coffee within 2 or 3 weeks, it will stay fresh, even if you keep it on your kitchen table (wrapped up and away from heat).
If you want to keep your roasted coffee for much longer, we find that freezing beans works best. You can remove the grounds or beans from the freezer and brew the coffee directly. But no matter what method you use, that newly-roasted aroma of coffee doesn’t last long (even with one-way valve and/or vacuum sealed bags). Alternately, once you receive your coffee you can transfer them “into an opaque, airtight canister of a size just big enough so that there is as little air at the top as possible. Catalogs and stores offer ceramic canisters, used also for other dry goods like pasta and rice, with metal rings that latch shut” (Kummer, 57).
There you have it. As long as you stick to a few rules, you’ll be able to preserve your coffee’s freshness until you need a new batch. Enjoy!
- Keep roasted coffee in an opaque container
- Keep it in a dry, dark and cool place
- Your freezer can be used to preserve freshness
- Keep your brewed coffee in an opaque thermal carafe for up to 45 minutes
- Store your coffee in your refrigerator
- Leave your bag of coffee open, exposed to oxygen
- Leave brewed coffee on a burner to keep it warm
Written by Coffee Mike
I like to include the following disclaimer below each of my blogs. I try to make references wherever applicable, but I’ve read many books, dozens of articles, watched documentaries and taken courses on these subjects over the years. I mention this because sometimes I may forget the exact source of my information, so I ask the authors to forgive me if I have not cited some information where I should have.
Kummer, Corby. The Joy of Coffee: The Essential Guide to Buying, Brewing and Enjoying. New York: Houghton Mifflin Company, 1995. Pages 52-57, 77 .
Pendergrast, Mark. Uncommon Grounds: The History of Coffee and How It Transformed Our World. New York: Basic Books, 1999. Pages 118, 388.
Sinnott, Kevin. The Art and Craft of Coffee: An Enthusiast’s Guide to Selecting, Roasting, and Brewing Exquisite Coffee. Beverly: Quarry Books, 2010. Page 43.