So today it’s been 4 weeks since we started the experiment and it was time for the last cupping. We’ve changed our cupping schedule from 14.00-15.00 (2 pm to 3 pm) to 16.00-17.00 (4pm to 5pm). This meant that we weren’t in the middle of the late lunch-rush when the cupping began. This in turn made it easier to focus while cupping.
As before we ground up 12 grams of the three differently stored coffees and a control sample. We later decided to skip the control sample as that coffee had been roasted slighlty darker and wouldn’t serve it’s purpose.
After having broken the crust and removed the foam we tasted the three coffees and this is were the differences became apparent. First of all; like last time we agreed on that no coffee should be stored this long no matter what method of storage being used. The coffees flavours had faded even more during the last week. But this is where we stopped agreeing. We scored and valued the 3 cups differently, but settled the score with …eh summing up the scores.
1st place: The freezer with 12 points
2nd place: The shelf with 10 points
3rd place: The fridge with 8 points
There wasn’t that much between the contestants this time around either, but the coffee from the freezer seemed to have an edge. I guess that this coffee would have increased it’s lead if we were to go on for more weeks. But why would anyone want to store their roasted coffee for that long?
As a conclusion for the entire project it seems that it’s better to store your coffee on the shelf out of sunlight and in an airtight container for up to 3 weeks rather than storing it in the same container (unopened) in the freezer and the fridge. But if you are going to store it for 4 weeks or longer (for some strange reason) you should store it in the freezer. This is true for coffee roasted for drip or french press. In case you have coffee roasted for espresso the freezer has an even bigger positive effect according to Tim W (having done a similar with this kind of coffee).
My theory is that the freezing and thawing process affects the coffee negatively but being frozen the coffee deteriorates more slowly than when stored on a shelf. For shorter periods of time the process of freezing and thawing makes the coffee from the freezer taste worse, but over time the deterioration of the coffee stored at room temperature is greater and will pass the combined effect of freezing/thawing added to the gradual deterioration of the coffee from the freezer.
We still have many questions unanswered. What would have been the differences between the coffees after 1 week? What would happen to a coffee that was less acidic? What if we opened and closed the bags every day?
This made us decide to repeat the experiment with another coffee and see what would be different. If you have any suggestions to aspects we should include in this test please leave a comment and let us know. Thanks for reading and sorry for all the pictures. I guess I just tried to compensate for there being only one in the previous installment.
Next week we will be testing to see how many unripes/defected beans there can be in a cup of coffee before you can taste it. We put our tastebuds on the line so you don’t have to!