We all know that coffee is unquestionably better when the beans are freshly ground. But what about those times when you just don’t have access to a grinder: holidays, friend’s houses, when yours has broken down, or you’ve simply picked up whole beans by mistake? Here's a guide on how to grind coffee beans without a grinder, and create a beverage that somewhat resembles a quality cup of coffee.
Why do we grind coffee beans, with or without a grinder?
Can you make coffee with whole coffee beans? In theory, yes - but it would take an exorbitant amount of time. We grind coffee beans to increase their surface area, giving them the optimum amount of contact with the water in order to release the flavour and aroma. The exact amount of surface area will depend on the texture of the grind that you create, which in turn is dependent on the brewing type you are using, and the result you are after.
We grind coffee beans right before brewing them to limit the chance for contaminants to affect their flavour and smell, but also to reduce the time they are exposed to oxygen, which is what destroys the potency and flavour of the beans. In fact, after just 15 minutes, ground coffee beans lose up to 60% of their aroma.
The key to a great tasting coffee comes in the control and consistency of the brew, mainly determined by the grinding of the coffee beans themselves. Even the very best coffee beans can be ruined by over or under extraction, or an inconsistent grind.
The best way to get consistent results is to do small amounts of coffee beans at a time, even if the option you go for allows for large batches. This way you can control the pressure exerted on the beans.
Which grind type should I choose?
Before you decide how you are going to grind coffee beans without a grinder, it is a good idea to know which type of grind consistency you are aiming for. Take a look at this handy table for a general guide on which brewing methods require which type of grind, and how to identify the coarseness and texture of each type.
The above table is just for general advice, and is not set in stone. There are many hacks and tricks online that people use with alternative grind levels for their brewing type, but we advise these types when first starting out.
The Aeropress for example supports a wide variety of grinds, from medium-coarse to fine, but their effectiveness will depend on the way you are using the brewer, as well as which kind of filter you are using. Paper filters for instance can take finer grinds as they have smaller holes, so you do not need to worry about sediment passing through.
The main reason we use different grind types for different brewing methods is to limit the likelihood of the coffee being over or under-extracted. We don’t want to go into a whole science lesson here, but broadly speaking, the larger the ground type (coarse) the quicker the water will pass through it - creating a weaker, under-extracted coffee.
On the flip side, finer coffee grounds will retain the water more and slow down the flow, creating a longer, more bitter and over-extracted coffee. This is a particular worry with espresso machines, where baristas also have to contend with other variables such as water pressure, and how strenuously the coffee grounds have been tamped.
How to grind coffee beans without a grinder
Grinding coffee beans in a blender or food processor
If you’re lucky enough to have one of the fancy blenders or food processors that come with a grind setting, then go ahead and grind coffee beans in a blender or food processor. If not, here are a few tips for using a blender to grind your coffee beans without a grinder.
Try not to blend your coffee beans in a blender for longer than 30 seconds at a time. The blades in a blender heat up with use, and any longer than this will end up scorching your beans, which can result in a bitter taste. You don't want that if you appreciate nice tasting coffee that isn’t too bitter.
To ensure this doesn't happen, grind your beans in a blender in smaller batches, ideally just the amount you will need. Use the pulse setting, rather than a continuous blend. This will stop the heat building as we mentioned before, but will also keep moving the beans around, exposing different beans to the blades at different times - a good way of ensuring all of them get close to the blades (if you’ve ever made a smoothie in a blender only to be left with chunks of fruit, you’ll know why this is important!).
As blending uses blades to break things up, it will generally produce medium to coarse grinds, but this will depend on what model of blender or food processor you have. You can try blending coarser grinds again to try and get a finer ground, but be wary of the heat produced when doing this.
Top tip: feel free to pick up the blender or pitcher between pulses, tilting it and shaking the beans around to stop them from sticking to the blades.
Using a hand-mincer or garlic press to grind coffee beans
It’s an obvious point, but if you’re using a mincer or garlic press to grind coffee beans, make sure it is washed thoroughly. No one wants a garlic tainted cold brew!
While this method will take longer due to the small number of coffee beans you can crush at once, the methodical and precise nature of the device means you will get a largely consistent grind with it.
Start out by placing a bowl to catch the grinds in as you go. The coarseness of the grind will depend on how many times you put the coffee beans through the press, so use it as you see fit - just be sure to keep it consistent!
Using a rolling pin to grind coffee beans
One common tool that serves well for crushing/grinding coffee beans is the humble rolling pin. Its width and even distribution of pressure mean that you will get a fairly even consistency, too. Pop your coffee beans in a Ziploc or freezer bag to hold them in one place, making sure to get rid of any excess air to prevent the bag from popping.
Start off by using the end of the rolling pin to press down firmly over the beans, breaking them up into smaller pieces. Now roll over the beans, exerting an even pressure that you can replicate with each stroke. Go from front to back and back again, and from each side. Once the beans feel evenly crushed, bunch them together into the middle, as you would when kneading bread, then spread it out again and repeat the process.
This method is not for the faint of heart - it’s definitely a bit of a workout - but if you are willing to put in the effort and pay attention to consistency, you can get quite a passable medium grind. This will be good for anything that doesn't require too fine a ground, such as a pour-over or Aeropress.
Top tip: if you don’t own a rolling pin, you may be tempted to use a glass bottle such as a wine bottle instead. We would advise against this. While that may be fine for rolling out dough, you will be exerting a lot more pressure onto the glass doing this, and the potential for it breaking is just too high. If needs must, then why not try a…
Using a hammer to grind coffee beans
Yes, really. Place the beans in a Ziploc or freezer bag to stop them from flying everywhere (you may also want to wrap the bag in a towel to stop the plastic from tearing). Press the hammer slowly but firmly over the beans to crush them, rather than striking them as you would a nail. It is best to go slowly from one corner of the bag to the other, then back again, to get as consistent results as possible.
This method will work when there is absolutely no other method available to you, but don’t expect miracles. The best kind of grind you can hope for from using a hammer would be a coarse to medium-coarse grind.
Using a spice grinder to grind coffee beans
How did we grind beans before the grinder? Well, both drinking coffee and grinding beans are older than you might think. Englishman Nicholas Book invented the first grinder sometime in the late 1600s, while England’s first known coffee house opened in 1650.
Grinders cost a huge amount of money, so most people used spice or corn mills to perform the same function. If you have one of these, then feel free to try it! Again, make sure it is clean and free of remnants of its previous use, as black pepper is not something you want in your coffee.
Follow the instructions as you would if you were grinding spices or pepper, but bear in mind that the end result you get will vary depending on the type of spice grinder or mill that you use. If the results are too coarse, you can put the beans through a few times to try and get a finer consistency, though this will only work with certain types of spice mill.
Using a knife to grind/crush coffee beans
It goes without saying that this is a last resort for coffee grinding, and that you must take care when using sharp objects. While this doesn’t require a sharp knife, it can still be risky, so don’t attempt this method if you aren’t comfortable with it.
First of all, we aren’t going to be using the edges of the knife at all. Instead, we will be using the wide flat side, as you would crush garlic. It’s best to use a chopping board under the knife so that you have a flat surface, and something to catch the beans on.
Start with a few coffee beans on the board, then place the knife on top so that all the beans are covered. Press down on the knife’s flat edge with the flat palm of your hand, trying to ensure that the pressure is equal across the blade. Try to replicate this pressure with all of the coffee beans as you go to get a consistent grind texture. It goes without saying that this will be coarse!
Using a mortar and pestle to grind coffee beans
This method will get you the finest grind of all the manual grinding options, and is the way a lot of people ground their beans in centuries past. When using a mortar and pestle, only fill the mortar about a quarter of the way, otherwise the beans will fly in all directions as soon as you put on a little pressure.
Using the pestle in your strongest hand, push down on the beans while also twisting. This should break the outer shell. Move around all of the beans and repeat this, trying to use the same amount of pressure each time. Don’t hit the beans up and down with a huge amount of force, as this will do nothing for your grind, and will mess up the consistency (not to mention tiring you out needlessly).
Roll the beans around the mortar as you go, using the bowl to add to the grinding motion as you move onto other beans. When you have reached the desired grind consistency, empty the mortar and move on to the next batch.
Top tip: a ceramic mortar and pestle will work best, as they are less porous and will not absorb the bitter taste and smell of stale coffee beans, something which can build up over many uses.
A note about blade grinders: don’t! These types of grinders will work at grinding your coffee beans, but as they use a blade rather than conical burrs, they will not be consistent in how they do it, meaning that some of your beans will be finely ground, some coarse, and the rest somewhere in between. This will lead to some of your coffee being over-extracted and some under-extracted, all mixing in your final drink, and leaving a somewhat chalky taste. In this case, it is better to get coffee that is pre-ground, or better yet, invest in a burr grinder. They are the only way to guarantee uniform and quality coffee grinds every time, and it is for this reason that many coffee shops use them.
Have we answered the question on how to grind coffee beans without a grinder at home? We think so, but it is worth remembering that the type of grind that can be achieved with these methods will vary massively depending on the time and effort you put in.
None of them will deliver the consistency that you would get from a burr coffee grinder. If in doubt about the quality of the coffee you can get from hand ground beans, we suggest opting for a French press (Cafetière coffee) as a brewing method, as it is both the most forgiving and takes the coarsest grind, something which most of the methods above can easily achieve.
If grinding coffee beans without a grinder seems like far too much work, all of our coffee beans are available pre-ground to different consistencies - simply select your brewing type from the drop-down menu when ordering your fresh coffee beans.