One-Way Coffee Degassing

Fresh, aromatic coffee is essential for roasters, which is what a customer desires in quality coffee. In order to provide the freshest coffee possible, and preserve the quality of coffee, it is imperative for roasters to pack and seal their coffee immediately after roasting in a sealed package.

As freshly roasted coffee cools, it releases carbon dioxide gas which is commonly known as the degassing process.  The degassing process can last a couple of days up to over a week depending on the roast and other factors.  Without the proper mechanism in place to release the carbon dioxide, coffee degassing inside of a sealed package will cause the package to swell and potentially burst.  Freshly roasted coffee can be bulk degassed; however, the problem with this approach, in addition to tying up inventory, is that environmental oxygen and airborne contaminants cause the coffee to rapidly lose its freshness, flavor and aroma. This creates a bitter taste that any coffee connoisseur will not tolerate.

In our industry, since the consumer’s taste has become more refined and accustomed to great quality coffee, roasters are under more pressure to deliver best quality products. Once consumers start drinking better quality coffee, they tend to not trade down. Studies also show consumers prefer consistency. The ability to maintain consistency and great quality is what will sell more coffee. This puts greater pressure on roasters to maintain and preserve great quality in their coffee through choosing the right species, roasting and blending variables as well as preserving freshness of their roast.

The solution is to employ the use of one-way degassing valves to help roasters preserve freshness and quality of their carefully roasted and chosen blend. The purpose of a one-way degassing valve is to allow carbon dioxide gas from freshly roasted coffee to escape from the packaging while keeping environmental oxygen and contaminants from entering the package. These valves are now standard features on coffee bags as well as lid containers. They cannot make the coffee taste better, but are crucial in preserving roaster’s carefully selected and roasted blend. There are two types of one-way degassing valves on coffee packaging: surface applied or heat sealed button one-way degassing valves.

The effectiveness of one-way degassing valves is measured by oxygen levels in the bag with lower oxygen levels, resulting in better coffee freshness and consequently quality. The industry standard range on the oxygen level is between 0.5-3.0% and will depend on number of factors: type of one-way degassing valve used, film/material that it is applied to, location where it is applied on the package and whether nitrogen flushing is used.

One-way degassing valve technology has developed immensely. It has evolved to include various enhancements that improve product functionality and ease of use. Roasters prefer to have smaller, thinner transparent valves that will not interfere with product packaging and provide the lowest oxygen levels possible. In other words, one-way degassing valves should perform the function but be as unobtrusive as possible. Plitek has been continuously working towards enhancing performance features of one-way degassing valves over the last twenty-five years with great success.

Coffee industry trend has shown an increase in usage of fractional packages. As consumers desire fresh quality, they buy more fractional packaged coffee that will be consumed within short period of time.

One of the Plitek product recently introduced to the market is the PLI-VALV Mini Valve; a one-way degassing valve for fractional packaging. The new valve is transparent and small, at 0.50”x 0.50” in size, with significant cost advantages over standard size valves. The applicator to the new PLI-VALV Mini Valve can apply up to 150 valves per minute. A custom engineered option is available to double the rate.

Another patented innovation recently introduced to the market is PV-25-FV; a one-way degassing valve with integrated filtering base that will additionally enhance valve effectiveness and help with product freshness and quality preservation. Its carefully designed structure inhibits coffee grounds from entering the valve and interfering with its functionality. It is one in a line of many product generations that help roasters provide the best quality coffee to their customers.

Whichever one-way degassing choice roasters make, one crucial piece of advice is to ensure the degassing options are consistently working and providing  the best oxygen levels. Roasters should have their bags randomly tested to verify oxygen levels. Granted, this adds additional responsibility, but it prevents having unhappy customers who will not tolerate stale coffee and influence them to select a different product. Furthermore, one-way degassing valve rate of application has direct impact on throughput and it is one of the important elements to consider when choosing your degassing options.


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