The effects of packaging and storage on green coffee

The effects of packaging and storage on green coffee

A lot has been researched and studied regarding the storage conditions of coffee. For ground coffee, roasted coffee, soluble coffee, you name it. Most research is done on the influence of packaging materials. Should it be in aluminium? Plastic? Should it be vacuum-packed? Does it need a valve? But also: do you store coffee in the freezer? Or not?

Research and technology on the best storage conditions for green coffee are much harder to find. Not that it has not been done. Shout out to the amazing research on nature.com that was published earlier this year. But as green coffee transport and storage is a huge part of our business, we wanted to investigate.

Investigating coffee transport and storage

It all started in 2019, when we did a transport project, where we looked into transport conditions, (measuring humidity and temperature in a reefer and a regular container), and compared how well different types of packaging protected against the transport elements.

Continuing research on shelf life

We took that opportunity to extend our research into shelf-life research. The different types of packaging were stored in two different warehouses: a conditioned warehouse (15˚C/60% humidity) and an unconditioned warehouse (ambient). We took samples over a period of 18 months and analyzed the SCA cup score, gave an ‘ageing score’ on a scale from 0-15, and analyzed physical and chemical composition.

This year our intern Rick Mannes, a BSc Food Technology student, analyzed all the data collected. Finally, after 3 years, we have the results. 

What we found after 3-years of investigation

We did not observe statistically significant differences between the types of hermetically sealed packaging, they perform quite similar over time. Jute-only bags do not protect the coffee well, especially over a longer period of time. 

The sensory scores observed between the conditioned and unconditioned warehouses were not very different either. However, we do see better quality stability at 18 months in the conditioned warehouse. 

Surprise and its disclaimers: Is it a surprise that the two different warehouses do not show big sensory differences? Yes and no.

Yes, well color me surprised

As mentioned above, there is not a lot of research into different types of storage of green coffee. But most of the research available shows that the conditions of the warehouse do matter. 

Nah, that figures…

There are several reasons why there might not be a big difference between the two types of warehouses.

  1. We used a very stable coffee; a washed grade 2 Guji Ethiopia. If we used a more unstable coffee, we might get different results.
  2. Both warehouses we used are located in the Netherlands, which has quite a stable climate. Yes, there are 4 seasons, but overall it is quite stable, never being extremely hot or cold. In addition to that, the unconditioned warehouse is of very high quality, with very high ceilings, and a lot of space between the exterior and the product. Meaning the conditions in the unconditioned warehouse were also quite stable. Using a warehouse of lower quality or in a different climate with more extremes, could lead to different results. 
  3. Hermetically sealed packaging is meant to protect from the elements. Meaning a well-closed Grainpro, Ecotact or other PE bag should protect the green coffee bean from the climate conditions. That is what they are made for. Again, unless the conditions are extreme, or the PE bags are not properly closed, your coffee should be protected. 
  4. Finally, although we see no statistically significant differences between the conditioned and unconditioned warehouse, we do see a bigger drop in quality at 18 months in the unconditioned warehouse. The fact that this result is not significant, could also be due to the number of times we repeated the analysis. 

Any other thoughts?

Of course, always. This explorative research only brings up more questions and shows that more, extended and detailed research on the topic of green coffee storage is necessary. There is so much to uncover and think about when reading this research, rather than reading our rants, we invite you to read the research linked below.

Read the research here, and use the data yourself

Download the shelf-life study “The effects of packaging and storage conditions on the sensorial quality of washed green Arabica coffee beans” here.

We also wanted to share our data with you as well. To look into, to experiment and play around with, or use in any research you may want to do yourself. You can find this here.