Coffee beans come alive when they’re roasted, it’s a fantastic bit of science. The processed green bean won’t really change over a period of about 12 months as long as it's stored correctly, however when it's roasted it comes alive from the ‘first crack’. This is the bean bursting open because the gases and moisture trapped in the bean expand and exert pressure to the point the structure of the bean can’t hold it. From this point on the bean is losing those gases.
The gas is mainly CO2 and as it seeps out, oxygen is allowed in and causes the bean to go stale. The crema on an espresso is caused by the CO2 still in the bean so a good way to see how fresh your coffee is to check the depth and colour of the crema.
95% of coffee in the UK is sold by the supermarkets, vacuumed packed coffee beans with an expiration date in a few years time, stored in a box in a warehouse before being placed onto shelves. This is a very cost effective way of selling beans as there is little to no wastage and manufacturers can mass roast and hoard stock. This is also what the average coffee consumer expects.
Slowly but surely consumers are switching to freshly roasted, a completely different way of approaching coffee and the taste benefits are obvious. The best before date on a bag of supermarket beans is simply a legal requirement. Stale coffee is safe to drink, it just doesn’t taste nice. The introduction of adding milk, sugar, honey etc was to make stale coffee taste nice. Freshly roasted coffee however with plenty of gas remaining doesn’t require any assistance to help it taste amazing. The coffee holds its cupping traits and contains sweetness and acidity in all the right ways.
So how long does coffee stay fresh?
2 weeks after roasting for a bean to be at its best, 4 weeks and it likely won’t yet have gone flat and stale, anything beyond and you start to get that supermarket cardboard taste and consistency. If the bean has been roasted dark, the gases escape faster and you can expect an even faster quality reduction.
Is this all marketing?
Nope. It really is impossible not to notice the difference, it’s like you’ve always bought 3 day old bread and suddenly got freshly baked. I promise once you try fresh coffee, supermarkets will kiss your trade goodbye.
What about coffee shops?
Is it easier to store powdered milk or fresh milk? Your average big chain coffee shop doesn’t sell freshly roasted beans. It’s easier to vac-u-pack some half decent beans and keep a plentiful supply in the store room than to put a 2 week deadline from the roaster. You’d notice if they used powdered milk but we’ve got so used to stale coffee beans that customers expect the taste. It’s also why a mocha frocha pup-a chino is on offer, anything to make it taste better.
Small, specialist coffee shops will often sell fresh beans, either purchased from a local roaster or roasted themselves. You can check a place sells fresh beans by asking when they were roasted. A great coffee shop will love this question. They may even display the date on the counter.
Is there a cost difference?
Unfortunately yes. The cost of bulk roasting, bulk packing and never being concerned with use by dates is far less than roasting the quantities required as and when orders come in, stocking a display and throwing out if they don’t sell. Smaller roasters are needed and overheads are higher. Lots of small order shipping is much more expensive than one big shipment, and chances are, your local coffee roaster is buying in much, much better beans than you’d get at a supermarket and in smaller quantities. It all adds up.
What brew method works best for fresh beans?
Any. Whatever method you use you’ll still taste the difference. The only recommendation I’d make is grind your beans at home if you can using a burr grinder.
If you have an all singing all dancing espresso machine then you’ll notice the difference with fresh coffee in the process before you’ve even had a sip. You won’t need to use the double wall baskets, the coffee will extract miles better and much easier.
Maybe one day supermarkets will have to make the move, approaching coffee like they approach milk, meat, bread etc; little and often with use by dates in days rather than years. This only happens if customers talk with their feet and buy direct from the roasters.