By Catherine Franks
Coffee storage is a subject that can be as complicated as you choose to make it (much like everything in coffee). There is certainly a lot of advice (and research) out there about keeping your coffee fresh. Here we are going to cut to the chase and share with you the basics of keeping those beans in the best possible condition once you get them home. If you want to get into more of the geeky side, follow our links down some interesting more scientific rabbit holes. If you don't have time for that, here's the basics you need to know.
What you need to know about freshness
Roast date matters.
The first and most important thing you need to know is that how you source your coffee matters. If you are buying your coffee from a specialty roaster the bag you buy should have the roast date on it. You may have noticed that coffee from a supermarket does not have a roast date, but instead has a best before date. That means that the coffee was probably roasted many months previously. Buy from a local roaster you know and trust or a specialty roaster with a good reputation online. They will be transparent about when the coffee was roasted and will give you a guide as to when you should use the coffee by, this is generally within 6-8 weeks of roasting.
How fresh should your coffee be?
There is a lot of debate over freshness and how soon you can start enjoying your coffee after roasting. When it comes to making espresso, coffee really needs to rest after roasting. Coffee that is too fresh tastes sour and sharp. In the shop we have found that coffee needs to rest at least one week before we start getting good espresso shots out of it. That is a minimum. We find that generally it is only after 10 days coffee starts tasting its best and with some coffees this varies tremendously. Some of our coffees have even been at their best a full three weeks after roasting. You can only really find this out by trial and error and this does really vary between different beans. Whereas one might taste at its best at three weeks post roast, another may be getting pretty flat by then. So as a general rule of thumb, if you are buying coffee for making espresso at home, let it rest at least a week before you start making shots with it. Filter is another matter and you can start brewing coffees within a day or two of roasting. Again, you should experiment and as you brew your coffee each day pay attention to how it may be changing - either developing flavours and 'opening up' or becoming flatter and less interesting. Take notes, learn and use that knowledge to constantly improve your coffee enjoyment!
To grind or not to grind?
Whereas the question of how soon to brew after roasting is a grey area, the question of how soon to brew after grinding is definitely not. Coffee should ideally be brewed within 10-15 minutes of grinding as once ground the coffee becomes stale very quickly. Find out more about what makes coffee go stale below.
So what if you don't have a grinder? We can definitely say that if you are looking to invest any money into brewing coffee at home, the best place to invest your money is in the grinder. This is much more important than spending on a fancy machine for making the coffee. Freshly ground coffee prepared simply in a cheap cafetiere or Aeropress is going to trump stale preground coffee made in an expensive espresso setup any day.
The quality of the grind MATTERS! The only exception about preground is if you do not have a good grinder (by that I mean a grinder with burrs as opposed to a blade). If the only grinder you have access to is one of those blade food processor/spice grinder type things, please let us grind your coffee for you in our grinder at Steampunk. Why? Because a bad grinder (a blade grinder is always a bad grinder) will grind your coffee really unevenly. Try it and see. Grind some coffee and pour it out onto a sheet of paper. You will see some big chunky bits and a lot of fine powder. So what happens when you brew your coffee is the large chunky bits don't extract properly (you get sourness) and the fine powder over extracts (you get bitterness). Sour and bitter - what a combo! Don't do it. Get us to grind it and store it carefully (see below) or ask Santa for a grinder.
What makes coffee go stale?
There are several processes at play that make your coffee go stale and many scientific papers with a whole lot more detail than we are going to go into here. But what you need to know are the key things that lead to your coffee getting stale: oxidisation, moisture and temperature.
Oxidisation happens when your coffee is exposed to air (specifically oxygen), this process is speeded up dramatically once the coffee is ground and much more surface area is exposed to the air. Moisture is the enemy of coffee which is porous and easily contaminated. Coffee that is exposed to moisture will begin to ferment and get mouldy, both unpleasant flavours to add to your coffee. Finally coffee should be kept cool. Higher temperature speeds up de-gassing of the coffee leading to aroma loss and the formation of unpleasant aromas in your coffee. Fluctuation of temperature leads to condensation and moisture, see above.
If you want to geek out further check out this SCA article on preserving freshness in coffee.
Ok, so if oxidisation, moisture and temperature are the key factors, what is the best way to store your coffee to mitigate them?
How to store coffee
Keep your coffee airtight
If oxidisation is the enemy of freshness, then the first obvious factor to consider when storing coffee it to keep it airtight. Depending on the packaging your coffee comes in and how long you generally have the packet before it is finished you could either store it in the packaging or decant it into a container.
Note regarding Steampunk packaging
Our retail packaging has been specifically designed to be as environmentally friendly as possible while getting the coffee to our customers in the best condition we can. Our coffee bags are made out of a fully home compostable material which is plant based and 100% plastic free. Although it does have a zip seal and a valve, if you will be storing your coffee for longer than a week or two, we would recommend that you store it in a dark airtight container.
Keep your coffee dry
Moisture is the other big enemy of coffee and again a sealed container is the best way to protect your coffee. Also keep it at an even temperature to avoid condensation forming! Moisture is one of the reasons for this next bit of advice:
DO NOT KEEP YOUR COFFEE IN THE FRIDGE!
Why not? The fridge is a moist environment and it is full of strong smells and tastes. Onion? Blue cheese? Not tastes you want in your coffee! Coffee is highly porous and is fantastic at absorbing flavours. In fact here's a great tip if your fridge smells funky - grind up some coffee and put it in the fridge in an open jar. Your coffee will absorb all the nasty smells and make your fridge smell great. But whatever you do don't drink that coffee afterwards... Broccoli Latte anyone?
Temperature and the freezer debate?
Ok, so the fridge is a big no-no. How about the freezer. Well that's different. If you have a big bag of your favourite coffee and can't drink it fast enough then freezing it is a good way to preserve freshness. Put it into airtight, ziplock bags in smaller portions and then maybe into a tupperware to keep it nice and protected. Then you can take out the small bags, one at a time, thaw them and use as needed. Do not thaw and refreeze. That process is going to build up moisture in your coffee (see the enemy above). That is why taking a bag in and out of the freezer to scoop from it is also a bad idea.
Want to read more on the freezer debate? Check out this interesting article byt Perfect Daily Grind: To Freeze or not to Freeze.
The best containers
Simple & Affordable
At Steampunk we sell a simple metal coffee canister that has a rubber seal and a clip lid as this is a great budget friendly option for keeping your beans out of the air. There is a reason that metal canisters are a coffee storage classic! They tick all the boxes - airtight, dark and keeps moisture out. Our one also has a cool 'Fuelled by Steampunk' sticker on the side (very important for kitchen aesthetics and flexing over your chosen brand of coffee). This is why our gift subscriptions include a canister in the first box we ship out. That way as future coffees arrive, you can pop them into the canister and keep them safe. As mentioned above, our packaging is not designed for long term coffee storage.
You have some other container options - going cheaper or going more expensive.
Cheap as chips & eco friendly
At Steampunk we are all about reuse! And cheapness. And making do and not buying stuff you don't need. That is always the most eco friendly option after all, though clearly not the sexy option in our capitalist world. So how about a glass jar? At home I have an incredible jam and Kilner jar collection and I suspect so do many others. Light is the enemy of coffee too, so if using a glass jar simply keep it in a cupboard rather than out on your counter. Also make sure you don't use a pickle jar, or anything that might have left an odour in the lid. Make sure your jar is sparkling clean and dry and has an airtight (with no smells) lid and you are good to go. Bargain eco friendly storage.
Fancy pants storage
At the other end of the scale are a selection of beautiful and expensive vacuum sealed canisters which aim to remove oxygen from around your beans between scoops. By all means indulge if you wish to, but if you don't have a grinder yet, invest in that first and store your beans in a tin canister or jar!
As we mentioned above, we really don't recommend this for Steampunk coffees because of our packaging.
But what if you have coffee from another roaster who uses a zippable plastic or laminated pouch for their coffee? There is a really interesting video about storage in a zip bag versus a vacuum container by European Coffee Trip. Overall they found that if you are going to use the coffee within two weeks, then storing it in the zip bag made no noticeable difference. If it takes you longer to get through it, then maybe an investment in a vacuum canister is worthwhile.
As with everything in coffee, the more you learn the more you realise there is to know. And the more you realise there is a raging debate over it! If you pick up anything from this rundown I hope it is the following:
1) Know your dates: buy your coffee only from a roastery that puts the roast date on the bag - buy little and often but don't just assume the fresher the better!
2) Invest in a grinder before anything else
3) Keep your coffee in an airtight container, out of the light and at a cool and steady temperature.
4) But for goodness sake, NEVER in the fridge!!
5) If you have too much coffee then it is ok to freeze it in airtight batches but don't take it in and out.
6) If you buy coffee from Steampunk, hurray that it is super eco friendly packaging, but make sure to store it in a canister or jar once you get it home!!
Need to get yourself a canister? Jump down below and pop one of these cuties into your basket....