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- Guides • Posted by Two Chimps • 11th October 2018
How To Choose a Grinder For My Coffee Shop
Choosing a grinder for your coffee shop doesn’t have to be a daunting task.
In this guide we’ll try and help you answer the question of “How To Choose a Grinder for My Coffee Shop?” Whether you need a grinder to pair with your espresso machine, or a secondary grinder to use with your cafetieres, read on and let us explain the coffee grinder types in more detail.
Burr or Blade?
When choosing a coffee grinder, the first decision you will face is if you’d like a burr or a blade grinder.
A blade grinder has a blade in the centre that looks like a propeller. The blade chops the beans up, and the fineness of your grind is controlled by how long you leave it running for. Often, you will find that using a blade grinder can result in coffee grounds being very uneven in size.
Further, if you want to achieve a fine grind, you will need to keep the coffee grinder running for a long time. This additional time can allow the blades to produce large amounts of heat which transfer to your coffee, giving your coffee a burnt taste.
A Burr grinder, on the other hand, crushes the beans between a moving grinding wheel and a non-moving surface. As a result, you will find you have a much more consistent grind. There are two types of burr grinders available.
The first is a wheel burr. The wheel spins incredibly fast which can make these grinders quite noisy. As a result of the wheel spinning fast, these grinders can be quite messy if they haven’t been designed correctly. These high-speed grinders often have flat burrs and much larger motors. The flat burrs provide a consistent grind, and the speed makes these ideal for a coffee shop espresso grinder.
The second option is a conical burr. This burr spins slower than the wheel burr which makes it a lot quieter and creates less mess. Conical burrs are less likely to clog up too, unlike cheaper wheel burr grinders. These low-speed grinders have a smaller motor and use gear reduction to reduce the RPM. They often have smaller conical shaped burrs (hence the name.) Due to these grinders having a slower grinding speed, less heat is transferred to the coffee which helps to keep the aroma of the coffee.
On-demand vs chamber
If you are looking for an espresso coffee grinder, you now have a further decision to make. Would you like an on-demand or chamber grinder?
An ‘on-demand’ coffee grinder is the more convenient of the two. Once set up, they are very simple to use and require you to simply load the hopper (we’ll get onto that soon), and select the size of the shot to be dispensed. In seconds you’ll have fresh ground coffee ready to be tamed and tamped.
With a chamber grinder on the other hand, you pre-grind your coffee into a ground coffee chamber. To dose your espresso, you pull the manual paddle to allow pre-ground coffee to fall into the portafilter. Chamber coffee grinders can be messy and wasteful. They also don’t produce coffee which is as fresh as an on-demand grinder as the pre-ground coffee has been sat in a chamber for a time.
For the freshest coffee, we would certainly recommend an on-demand grinder. Be careful of the time it takes to dose a shot, however. Some of the cheaper, home-style on demand grinders take around 20 seconds to grind enough coffee for a double shot; not ideal if you have a busy café!
Tamping
Next up in the process of using a coffee grinder for espresso is taming and tamping. Tamping is the process of manually pressing the coffee grounds to produce a flat surface before the coffee is locked into the espresso machine group head. The purpose of tamping is to compact the grounds, so the water pushes through the coffee bed evenly.
If the coffee bed is not level, the water will find it easier to pass through the shallower side of the coffee bed. This will result in over-extraction for the shallower side of the bed and under extraction from the thicker side.
The first thing to do when starting the tamping process is to even your grounds out. Just run your finger across the portafilter to re-dispense your coffee grinds. Remove any excess ground coffee too. This process is known as taming.
After your ground coffee is nice and even, it’s time to assume the position! With your tamp in hand, keep your wrist straight, and your elbow slightly bent at around 90 degrees. Apply medium pressure to the bed of ground coffee.
Lastly, give the portafilter a quick final wipe with your hand. This will remove any loose coffee from the rim.
Place the portafilter gently into your espresso machine. If you knock the portafilter while placing it into your machine, this can loosen the puck and create a small gap between the coffee and the edge of the portafilter.
This gap will allow the water to run easily through it and will lead to an under extracted coffee bed. This process is known as channelling.
Grinding for a cafetiere or another brew method
If you are wondering how to choose a grinder for my coffee shop when you are using a cafetiere or fresh filter coffee, then one of the following would suit you better. An espresso grinder as mentioned above will produce a very fine grind – almost a powder in fact. The grind size for an espresso is too fine to use in a cafetiere, or any other brewing method. For these methods, a coarser grind is required.
A deli grinder has a broader range of grind sizes available. Pre-measure your coffee beans, and grind precisely what you need, straight into your brew device. By pre-measuring, there is no waste. Awesome.
Alternatively, a hand grinder could suit. As the name states, these are powered by hand to grind coffee. These will undoubtedly take longer to grind a dose than their electric brothers, but they are much cheaper.
Grinder Burr Maintenance
It can often be hard to see when your coffee grinder burrs need replacing. The change in your burrs will be a slow and hardly noticeable change. However, there are a few ways you can check to see if your burrs need replacing. Check the manufacturer’s recommendations, but as a rule, the burrs should be replaced around every 1000kg of coffee.
The most obvious way to tell if your burrs need changing is to feel them! Disassemble the grinder, wipe down the burrs and carefully rub your finger over the edges. If they feel dull, then they need changing.
If you find that you need to keep grinding finer, it’s likely your burrs are going to need replacing. Without their razor sharpness, the burrs won’t grind with as much precision and will result in the beans having a coarser grind.
Grind a few beans and take a look at the results. Do the grounds vary in size? Time to change.
Dull burrs do less grinding and more mashing. The sharp edges will stop slicing the beans and instead will crack and smash them into smaller pieces. It’s important to remember that all grinders have a tolerance.
So don’t panic if there’s a tiny bit of variety to your grind size. Once the size of your grounds vary so much that you can’t make out a definite size, you know your burrs need changing.
Size of hopper
The hopper stores the coffee beans until they are ready to be ground. The hopper sits on top of the grinder, and the beans are fed from the hopper to the grinding chamber. With hoppers, there’s an extensive range of sizes to choose from, ranging from 250g to as large as 6kg.
Choosing the size of your hopper depends on two things. The first being how large your business is and how much coffee you’re likely to go through in a day. The second is how often you would like to refill the hopper. For instance, if you have a small 250g hopper and you are using 1kg of coffee a day, you will need to refill this four times across the day. Is this feasible for you, or would a 1kg hopper suit your needs best?
And so, we have come to the end, my friends. We hope you have all the information you could ever want and need about to know ‘how to choose a grinder for my coffee shop’.
If you don’t, get in touch with us and we’ll be more than happy to help.
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