The Great Coffee Experiment: storage v time

|by Ryde Jeavons
We all know that coffee storage is key to maintaining quality of the beans. But we really want to know just HOW important it is, what happens when you try to extract 6 month old beans that have been properly stored, versus 6 month old beans that have not been stored correctly. So we’ve decided to conduct an experiment that tests the extraction of an espresso shot on the same coffee, stored in different ways, over time to try. Some say the ideal window for the best espresso extractions is when the beans are around the 21 day from roast mark and others say anywhere up to 2 months! Our aim is to find the best window for espresso extractions, as well as try and discover ways to salvage coffee from different states. We’ll be look at the factors that play a part in creating a good coffee, including richness of flavour, strength of aroma, sweetness and the consistency and volume of the crema. One important thing to note, is that espresso making is not an exact science. There are a multitude of factors like brew temperature, coffee dosage, extraction time, and the shot volume produced. On a home machine and grinder, things can be slightly different day to day, so for the sake of the experiment we are attempting to stabilise some elements of the extraction process. The grind of the beans will be as close to a brown sugar consistency and size as we can, this grind size suits the machine we are using. Each shot we are extracting will be ….g of coffee and at a 30 second pull time. All the shots will be made and tasted by Ryd. From the initial base shot, we will try and give recommendations based on the qualities (taste, aroma, quality of shot) ways to get a better shot out of the coffee. Other parts of the method are as follows:
  • Our correctly stored beans are packaged in their bags, sealed with a heat sealer, then place in an airtight container and stored in a dark place.
  • Our incorrectly stored beans are packaged in their bags, folded down with a bulldog clip holding them closed.
  • Our freezer beans are stored in their bags, sealed with a heat sealer.
The time variables will be same day as roast, 1 week from roast, 35-40 days from roast, 2 months from roast and 6 months from roast. So we’re in it for the long haul but we are determined to find some interesting results, and really curious about what will be ahead. We have a few hypotheses about what each coffee will bring in an extraction, but we are looking forward to having some expectations shattered and others confirmed. For instance we can almost say for certain that a same day as roasted coffee will be far too gaseous, and the crema will bloom quickly, then dissipate leaving a very sour taste. And we are fairly confident that the correctly stored coffee will taste good for up to 2 months. We don’t have too much faith in any of the ground coffees, especially the incorrectly stored ones. We think after the first day, and maybe pushing it to one week, they will be flat, tasteless and with very little aroma. After that… we just don’t know, but soon(ish) we will find out. Beyond that, we are curious to find out just how much impact that freezing the coffee has on the extraction. It is said to preserve the shelf life of the coffee for up to two months, but we are really curious what the freezing does to the flavours, and what kind of difference between frozen and thawed beans will be. Supermarket beans are a whole different story. Because we are unable to know the actual roast date of them, plus the fact that most of them have already been stored for up to 6 months before hitting the shelves, we don’t have much faith. What we are interested in is finding out whether these beans are done from the get-go, or whether storing them correctly (or in the freezer) will make a difference. We’ll update the results table below with links to the full reports on each extraction.
Time v Storage Same Day 1 Week 35-40 days 2 months 6 months
Whole beans (stored Correctly)
Whole Beans (stored incorrectly) na
Whole beans (stored in Freezer) na
Ground beans (stored correctly) na
Ground beans (stored incorrectly) na
Ground Beans (stored in Freezer) na
Supermarket Brand (stored correctly)
Supermarket brand (stored incorrectly) na
Supermarket brand (stored in Freezer) na
If there is anything you would like to add to the experiment, or if you have any hypothesis you would like tested, let us know!

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