The Science and the Art
Freshness is really important in coffee. Your coffee can be too fresh however! After roasting, it is important that the large amount of carbon dioxide (CO2) is released from the coffee. Too much CO2 can lead to carbonic acid as CO2 binds with water (H2O) to create carbonic acid (H2CO3) and this tastes really bitter.
We therefore rest our coffee for you. This ensures that when your delicious coffee arrives it is ready to brew straight away.
We pack our coffee in specially designed bags that are designed to seal in the freshness. This will ensure your coffee will stay super delicious.
How old is your coffee??
We aim to dispatch coffee within two weeks from the roasting date.
Managing stock levels this way is quite hard; it would actually be easier to roast to order. However, by having a small amount of rested coffee in stock we can offer next day delivery on most occasions and you will be drinking coffee that has been rested and tastes delicious and smooth.
Fresher than fresh?
If you prefer to receive coffee that has the freshest date please let us know in the comments section during the checkout. We can then pick the coffee from the shelves that has the freshest dates for you.
Coffee roasting creates CO2
During the roasting of coffee, thermally driven chemical reactions lead to the formation of gases, of which a large fraction is carbon dioxide (CO2). Part of these gases is released during roasting while part is retained inside the porous structure of the roasted beans and is steadily released during storage or more abruptly during grinding and extraction. The release of CO2 during the various phases from roasting to consumption is linked to many important properties and characteristics of coffee. It is an indicator for freshness, plays an important role in shelf life and in packaging, impacts the extraction process, is involved in crema formation, and may affect the sensory profile in the cup. Indeed, and in view of the multiple roles it plays, CO2 is a much under appreciated and little examined molecule in coffee.
Why off gassing is Critical
After roasting we must ensure that CO2 can easily be released from the beans. The ideal way is to store coffee in a coffee bag with a one-way valve with the bag standing upright. As the coffee is off gassing the CO2 is released and the CO2 forces any oxygen out of the bag. CO2 is heavier than O2 and will create a protective layer on top of the coffee beans preventing the oxygen from oxidising the coffee beans.
Carbonic Acids due to Excessive CO2
If the coffee is not able to off gas then the excessive CO2 in the coffee beans will bind with H20 during extraction and create H2CO3 which is carbonic acid. This has a sharp bitter taste. This is why we recommend resting coffee but resting is more than just waiting. It is important that the coffee is stored inside the coffee bags and that the bags are kept upright. Stacking the coffee bags on top of each other can block the valve and the pressure of the bags on top of each other prevent correct off gassing. Placing coffee beans in the grinder hopper allows the coffee beans to continue off gassing. There will again be a protective layer of CO2 on top of the coffee beans inside the hopper. The bottom of the grinder will allow some oxygen to enter the environment so whilst this is not ideal, placing coffee beans in a hopper will speed up the off gassing period. Avoid taking off the lid of the grinder as this will cause a turbulence an increase risk of oxidation.
How we Off Gas
When we roast coffee we rest the roasted coffee in resting bins for a certain time. We do this before we pack the coffee in bags. This allows the majority of the CO2 to escape before we pack. With this method we have found that even after the 24 hours the espresso is palatable but not ideal just yet – it still needs to rest. Once you have received the coffee and serve it, the coffee should be completely rested.
Stacking Coffee at our Roastery
After resting the coffee in bins, we store coffee on our shelves. Due to logistics we stack the coffee. If we were to keep coffee bags upright then they would swell. This swelling would make it difficult to pack and could make the bags burst in transit.
When you receive your delicious coffee please ensure that you keep the coffee upright on your shelves. We like to keep our coffee happy!