A Guide to Understanding Coffee Grinders
A coffee grinder is a useful appliance used to crush whole coffee beans into smaller more uniform particles which can then be brewed in a coffee machine to make your desired cup of coffee. Coffee grinders are perhaps the most essential tool in unlocking the true notes and flavors present in the coffee you brew.
In this post, I’ll cover some of the basics of coffee bean grinders including grinder types, features, terminologies, benefits and factors to consider before buying a grinder. Hopefully this information will equip you with important grinder basics and knowledge necessary to choose the right grinder.
Table of Contents
- 1 How Coffee Grinders Work
- 2 The Benefits of Freshly Ground Coffee
- 3 Dialing in your grinder
- 4 Optimal Grind Settings for Common Brewing Methods
- 5 How grind size affects coffee taste
- 6 What is Grind Consistency?
- 7 Types of Coffee Grinders
- 8 Factors to Consider Before Buying a Coffee Grinder
- 9 FAQs
How Coffee Grinders Work
Coffee beans need to be put into a container in the grinder called a bean hopper before the grinding process starts. In the case of burr coffee grinders, there are 2 sets of abrasive surfaces called burrs, which are responsible for grinding the coffee beans. One burr is attached to the grinder body, and therefore stationary, while the other is connected to the motor which spins rapidly. When the burr grinder is turned on, the coffee beans are led from the hopper into a space between the two burrs, where they are progressively crushed into smaller fragments as they move through.
The space between the burrs can be adjusted in order to bring them closer together or farther apart, which causes the resulting grinds to be finer or coarser respectively. This is commonly referred to as adjusting the grind. Eventually the grinds exit the burrs as small, uniform granules which are pushed through a chute and into the catcher.
Blade grinders, on the other hand, work just like regular blenders, using steel blades revolving at high speeds to slice the coffee beans over and over again until particles of the desired size are left.
The Benefits of Freshly Ground Coffee
The goal of grinding coffee is to get the flavors and aromas sealed inside the bean and dissolve them in water to make a delicious cup of coffee. While roasted beans contain a protective shell that can keep these aromatic compounds intact for several weeks, ground coffee reacts with the air almost instantly and flavors are lost within minutes due to oxidation and evaporation. For this reason, it is always advisable to brew your coffee immediately after grinding, as opposed to buying pre-ground coffee.
Pre-ground coffee bought off the shelf at a grocery store may have been ground weeks before and subsequently lost most of the flavor – the vacuum packing only helps so much. Buying from a local roaster is slightly better, although some of the aromas could still be lost depending on how long it takes you to get back home and brew the coffee. Experts recommend brewing coffee no later than 15 minutes after grinding.
A good grinder doesn’t come cheap though, which is one reason why you might consider sticking with pre-ground. Well-built grinders can range anywhere between $150 to $300, and high end Espresso grinders may cost upwards of $450. However, once you take the plunge, you will taste the difference — and wonder what took you so long.
Dialing in your grinder
If you’ve spent time researching or reading about coffee grinders, chances are you’ve come across the term “dialing in”. This phrase simply refers to finding the ideal grind setting on your grinder for a specific brew method or for your particular style of coffee. Whether you’ve bought a new grinder, replaced the burrs or just switching roasts, it is absolutely necessary to dial in the grind so that you can make a delicious cup of coffee. Dialing in the grind can be compared to finding the clearest frequency of a radio station, on those old analog stereos.
Each grinder is different, and coffee beans come in different varieties, sizes, and moisture levels so there isn’t a “one-size-fits-all” solution to dial in the grind. At the right setting, the brewed coffee is at its most focused and balanced taste. Grounds which are either too fine or too coarse will lead to over- or under-extracted coffee.
Ideally you should get a grinder which has many grind settings – at least 40, so that you can have the flexibility and range to dial in the perfect grind which suits your preference. Little adjustments in coarseness can make a big difference in taste. Additionally, grinders that have an electronic timing functionality are also preferable because they can save your grind settings ensuring consistency and repeatability of results.
You might need to grind through several ounces of freshly roasted coffee when dialing in your grinder, but having a good grinder should simplify this process and minimize waste. Some burr grinders perform better after you’ve ground a few pounds of coffee through them (this is known as seasoning or breaking in the burrs).
Optimal Grind Settings for Common Brewing Methods
Even after dialing in your grinder, keep in mind you cannot choose one grind size and use it in every scenario. There are different brew methods each requiring different sized coffee particles for optimum results. Similarly, different types of coffee machines are designed to extract flavor and aroma from the coffee in a different way. Some are versatile enough to handle different ground sizes, while others are purpose built for espresso.
The chart below shows the ideal grind sizes for some of the most common brew types, along with a description of how the grounds look or feel like. You can start here and make small adjustments as needed.
|Grind Size||Description of how the grounds look or feel||Brew Type|
|Very Coarse||Contains large particles, but beans are still thoroughly broken up. Similar to ground peppercorns.||Cold brew coffee brewing (e.g. using your Filtron or Toddy Brewer), Cowboy coffee|
|Coarse||Contains distinct particles. Similar to kosher salt/sea salt used for canning and pickling.||French press, Percolators|
|Medium-Coarse||Gritty, but no slivers of grinds. Looks like coarse/rough sand.||Chemex, Clever dripper, Cafe solo brewer|
|Medium||Feels like regular sand||Aeropress, Flat bottomed drip brewers, Cone shaped pour over brewers, Siphon brewers|
|Fine||Very smooth, but you can still feel individual grains. A little Finer than sugar||Espresso, Stovetop Espresso / Moka Pot|
|Extra Fine||Cannot feel individual grains. It’s the same consistency as flour or powder.||Turkish Coffee (Ibrik)|
How grind size affects coffee taste
The grind size of coffee determines the amount and rate at which flavors present in coffee are dissolved in water, also known as coffee extraction. Finer grinds, have more contact with water due to a larger surface area, and extract better and more quickly while the reverse is also true. However, if the grinds are too fine or the brewing time is too long then over-extraction takes place, whereby the resulting coffee tastes bitter, dry and hollow. Meanwhile, under-extraction occurs when the grinds are too coarse or the brewing time is very short, causing the coffee produced to taste sour, acidic and salty. Coffee that is ground to an ideal size and brewed for the required amount of time is well extracted and balances sweet and acidic flavors.
What is Grind Consistency?
If the coffee grounds vary wildly in size, it makes sense that the extraction will be uneven and unpredictable. What happens is the smaller fine coffee particles get over-extracted while larger coarse particles are under-extracted, and the flavor of your coffee becomes muddled. This grind inconsistency or unevenness, prevents you from getting the best flavor out of your coffee beans and makes it almost impossible to replicate or repeat a specific recipe of coffee.
To get a consistent grind, your grinder needs to crush coffee beans into particles of a similar size, without grinding any of them too much or too little. This proves to be a difficult task for most cheap coffee grinders. Blade grinders are especially notorious for producing an inconsistent mixture of larger and smaller grinds (commonly referred to as “boulders” and “fines”), which extract at different rates, and the coffee brewed ends up tasting unpleasant.
Always opt for high-quality burr grinders to ensure grind consistency and a delicious cup of coffee – although it is not unusual to have some degree of grind inconsistency even among the most expensive of these. Inconsistent grinds could also be a sign that your grinder’s burrs are worn out and need to be replaced.
Types of Coffee Grinders
Coffee bean grinders can broadly be categorized into two main groups, based on their grinding mechanism: blade and burr grinders.
a. Blade Grinders
Blade grinders are far less expensive than most burr grinders, making them a viable option for people who want to grind coffee on a tight budget. As the name suggests, they use blades to chop up coffee beans, and their mode of operation is no different from a blender or food processor. Once loaded with coffee beans and turned on, the stainless steel blades rotate very rapidly slicing up the beans progressively into smaller and smaller fragments. The coarseness or fineness of the ground coffee is determined by how long you grind the coffee beans. In theory, the longer you let the blades spin, the finer the grounds become.
It’s almost impossible to get a consistent grind with this type of grinder because all the beans are placed together and cut in a random and unpredictable manner, and you typically wind up with particles ground to different sizes. The grounds therefore extract at different rates which leads to inferior coffee quality. In the worst case scenario, grinding for too long will turn most of the coffee beans into dust making the resulting coffee very bitter and unbearable.
Additionally, blade grinders are not ideal for coffee grinding because the blades can generate significant heat which could burn the grounds causing the flavorful aromas to evaporate and you are left with bland coffee which has a burned taste. Blade grinders also produce more noise and static than most burr grinders.
If you want a cheap, straightforward grinder that doesn’t take up much space then a blade grinder might be what you need. The only caveat is that you have to contend with low quality, inconsistent coffee. However, most blade grinders are great if you’re looking to grind spices, herbs, and nuts. I do NOT recommend getting a blade grinder for grinding coffee.
- Small size – compact
- Grind spices, herbs, nuts
- Poor Grind Quality
- Inconsistent grinds
- No Grind Settings to Choose From
b. Burr Grinders
Burr grinders work by forcing coffee beans between two grinding burrs, where they are crushed in a relatively consistent manner compared to blade grinders. Burr grinders usually have multiple settings, allowing the user to adjust the coarseness of the grinds produced. Burrs can be made from either stainless steel or ceramic material. Very little heat is created during the grinding process, leaving the coffee flavors intact.
Burr grinders can be divided into 2 categories depending on whether they have flat or conical shaped burrs. Conical burr grinders utilize two cone-shaped plates that fit inside each other to grind the coffee while flat burr grinders use two horizontally placed serrated rings. In both cases one burr is stationary while the motor turns the other.
Although the beans are drawn in between the two burr shapes from different angles, they end up being crushed uniformly. Some coffee geeks like to speculate on which burr shape is better, but both burr types are known for their flexibility and quality. As far as I’m concerned, you really can’t go wrong with either one.
Although they are usually more expensive than blade grinders, burr grinders give you more control, superior grind quality and consistency which is why most coffee experts recommend them. I must mention though, that burr grinders aren’t equal – higher quality burr grinders last longer and grind more consistently than cheaper burr grinder models.
- Better Grind Quality
- Consistent Grinds
- Easy to adjust grind size
- Many Grind Settings
Factors to Consider Before Buying a Coffee Grinder
With hundreds of coffee grinder models on the market, choosing the right one can prove to be a challenging task for many. To help you narrow down your options, I’ve rounded up the main factors that you should take into consideration while hunting for a good coffee grinder.
Manual or Electric
Manual grinders can come in handy if you’re strapped for cash or if you find yourself away from home often and can’t stand to be without a fresh cup of coffee. Most of these little hand crank gems are small enough to pack in a bag, make little noise and offer quality consistent grinds comparable to their electric counterparts.
Manual grinders also tend to last longer than electric grinder due to their simplistic construction. The only downside is that they might take up too much of your time and energy, especially if you want to grind for multiple cups.
Electric grinders are arguably more convenient because they grind quicker and only require the touch of a button. They also offer a wider range of grind settings and other customizable options, so dialing in for the perfect grind is relatively easy. You are better off going for a well-built electric burr grinder if cost isn’t an issue, or if you have no plans of moving from place to place with it.
Intended Brew Method
Whether you want to do coarse grinds for French Press or fine grinds for Espresso will have a bearing on the kind of grinder you should select. Very few coffee grinders are versatile enough to grind for all brew types – some are only good for medium to coarse grinds while others are purpose built for very fine grinds required to make Espresso. Either way, you want a grinder that will grind consistently for your desired grind size. You can usually tell what grind size a grinder is most adept at by reading the seller’s specifications as well the customer reviews.
Knowing your brewing requirements will go a long way in helping you to figure out which grinder to choose. I highly recommend going for a purpose built espresso grinder like the Baratza Vario or Rancilio Rocky if the quality of your espresso very important to you. Espresso is made using very fine coffee particles, which requires a highly precise grinder capable of producing a consistent grind at a very fine setting. If you want a general purpose grinder for normal brew methods which don’t need as much precision, then you should be quite happy with a less expensive burr grinder.
Blade or Burrs
Blade Grinders are not recommended for coffee grinding because it’s basically impossible to achieve a uniform consistent grind, which means that you will almost always make bad coffee with them.
Burr grinders grind relatively better but as noted earlier, the quality and precision of burrs differs from one grinder to the next. Just because a grinder uses burrs is not an automatic guarantee that it will grind consistently. Some burrs are made from low quality materials, and they are likely to perform poorly and have shorter lifespans. If you’re not sure about the quality of burrs check the material. Ceramic is a good material.
The burr quality can also pretty much be discerned based on the overall price of the grinder – the more expensive a grinder is, the higher chance it has better burrs. Be cautious with very cheap burr grinders costing less than $70 – in my experience these tend to over-promise and under-deliver on results, and more often than not lead to disappointment.
Most online shopping stores including Amazon, give you access to dozens of reviews written by customers who previously purchased an item. It’s always a good idea to spend time browsing through these reviews to help you gauge whether a specific grinder model would be a good fit for you. Customer feedback is a useful resource because it provides you with real world information about how a grinder works, plus there are certain grinder aspects which are not easy to figure out on the surface.
One important quality that you should check for in a grinder’s reviews is the durability, so that you can avoid getting a poorly-built unit which will give out within a matter of weeks. But because grinder parts may wear out or break down with time, you should confirm that the seller has spare parts available. At the bare minimum, most sellers should offer replacement burr sets, in case yours get dull.
If you’re not a mechanically inclined person, the user reviews are a good place to check whether a grinder is easy to use. Some grinders are rather complicated when it comes to adjusting the grind or disassembly, making them hard to use or clean.
Noise and static production can be a big issue for some people, and there are few reliable ways to know this aspect of a grinder, short of reading customer feedback.
1. How do I clean my coffee grinder?
Specific instructions on how to disassemble and clean your coffee grinder are contained in the grinder’s instruction manual. You should make a point of cleaning your grinder at least once every 2 weeks or anytime you change roasts. Regular cleaning prevents accumulation of oil and residue from previous grinds which could degrade the grinder’s performance and negatively impact the coffee flavors. Some manufacturers include cleaning tablets which can be ground through the machine, to clean it.
Always make sure the grinder is unplugged before starting to clean it.
2. How long does it take to grind coffee beans?
The time it takes to grind varies from grinder to grinder but it generally comes down to the level of fineness you want to achieve and whether you’re using a manual or electric grinder. It roughly takes an electric grinder 30 seconds to do fine grinds, while hand grinders require 3-4 minutes for the same.
3. How long will my grinder last?
There’s no accurate way to predict how long your grinder will last but popular Baratza burr grinders can typically grind 1500 pounds of coffee, which is approximately 5 years of daily use. Burrs may become dull and need replacing from time to time. One way you can tell that you need new burrs is when your grinder can no longer do consistent coarse grinds.
4. How to reduce static in my grinder
Static buildup in a coffee grinder can be an annoying problem especially when it causes fine grounds to fly around or stick to the sides of the bin, creating a huge mess in the process. One way you can try to reduce the effects of static is to sprinkle 3-4 drops of water on your beans while they’re still in the hopper, before your grind. Another way is to add steam or moisture in the collecting bin. Some experts simply recommend waiting a few seconds to allow the static charge to drain away, before gently tapping the sides of the bin.
5. What are some great grinder recommendations?
If you’re looking for a quality entry level coffee grinder, you can’t go wrong with the Baratza Encore or Breville Smart Grinder Pro. In the high end espresso grinders category I highly recommend the Rancilio Rocky and the Baratza Vario. If you prefer a manual grinder, check out the Handground Grinder or the Porlex Mini.