Are One-Way Valves Right for Your Coffee Packaging Process?
Coffee is a culture, a lifestyle, a science, and an art all its own. Whereas once canisters dominated the market and consumers had to visit a cafe or specialty shop to get a gourmet brew, today specialty coffee is accessible on most store shelves worldwide. This is possible largely because of modern coffee packaging processes and technologies like the one-way valve. Is this packaging technology right for your coffee business? In most cases, the answer is a resounding 'yes'.
Degassing coffee, carbon dioxide, and quality
After roasting, coffee releases carbon dioxide gas at rates of up to 1000cc per pound for a period of days to weeks. The darker the roast and the shorter the roast time, the larger the amount of gas which is released and at a higher rate, according to a new study published in the Journal of Agricultural and Food Chemistry. This poses a problem when a roaster desires to package coffee shortly after roasting at the peak of its freshness: The build-up of carbon dioxide gas inside of the package can cause it to burst. so the coffee must be 'degassed'.
One solution is to let the coffee 'rest' in the open air to allow the release of carbon dioxide. However like many products, when coffee is exposed to oxygen it begins to oxidize and stale. Staling causes off-flavors, and you've worked way too hard on perfecting your roast to allow anything about your coffee to be 'off'.
The Specialty Coffee Association of America agrees: "It has been found that most of the compounds responsible for the aroma of freshly roasted beans are very susceptible to oxidation and can be lost quickly after roasting. Some work has determined that degradation of freshness occurs as soon as coffee has contact with oxygen."
So on one hand, roasters want to package coffee at the height of freshness, but on the other hand also need to allow carbon dioxide gas a way to escape that doesn't compromise package integrity. Enter: the one-way degassing valve for coffee packages.
What are one-way degassing valves?
One-way valves, or degassing valves, are a form of Modified Atmosphere Packaging (MAP) used in a multitude of industries but are especially popular in the coffee market. Here's why: as carbon dioxide gas builds inside of the package, the one-way valve allows it to escape while at the same time preventing oxygen and other contaminants from entering.
A small plastic piece usually affixed to the front or inside front of the coffee package, one-way valves do not obstruct package graphics, marketing, or functionality. Sometimes they look like nothing more than a pin-hole, other times they may look like a clear plastic sticker. Most consumers don't even notice them! But what they will notice is how consistently fresh their coffee is.
How are one-way coffee valves applied?
One-way valves can be pre-applied to the coffee bag or added inline during the packaging process by a coffee valve applicator. When affixed during the packaging process, the valves must be oriented the right way to work properly. So how do you successfully orient tens of thousands of valves per shift? With vibratory bowl feeders. This equipment gently shakes the valve around a conveyor chute that is oriented in the direction that we want to apply the valve. As the valves work around the outside of the bowl, they are feed into an exit conveyor. This conveyor then leads directly to the valve applicator. Vibratory feeders seamlessly integrate with any of our vertical form fill seal coffee packaging machines.
Viking Masek's coffee valve applicator
At Viking Masek, coffee is one of our top markets, so we've invested in creating a custom one-way degassing valve applicator for our vertical form fill seal machines. Here's how it works:
- The valve applicator holds the valve in the correct position underneath the film web.
- Above the web, a heated anvil with a pin presses down and applies the valve to the bag.
- The pin pokes a tiny hole in the bag which the valve covers.
- Heat permanently adheres the valve to the film and makes it part of the bag. The amount of heat, time, and pressure needed to apply valves varies depending on the type of valve, bag material, and machine speed.
There are several different types of degassing valves used in coffee packaging: rubber seal, filter, and pressure sensitive. We work with top valve producers and recently have partnered with a company that manufactures the only pressure sensitive one-way degassing valve with an integrated filter. Our end customers love the results.
When to use one-way degassing valves
One-way valves can be used in almost all coffee packaging applications. The question becomes more of the length of your post-roasting supply chain. If you are a roaster or cafe that packs and sells their coffee fresh on a daily basis, your consumers do not expect or desire a long shelf life. They will likely use your coffee within a few days. In this situation, your post-roasting supply chain is very short. A one-way valve certainly would not hurt and may even help with freshness, but is not absolutely necessary.
However, if you simply desire a longer shelf life for your product, or if you ship your coffee to retail stores, outlets, cafes, or end consumers, a one-way valve is a must-have part of your coffee packaging process. Your post-roasting supply chain is much longer, both in time and distance. Your end consumer may not receive and brew their coffee until weeks or months after it is roasted, necessitating a shelf-stable package.
Does your coffee production process need a check-up?
How long has it been since you reassessed your entire coffee production process? There may be hidden inefficiencies present that are holding your business back and decreasing the quality of your roast. Get a leg up on the competition by downloading our free Coffee Production Planning Calculator.
Originally published 2/23/2017, updated 4/15/2018.