What Is The Purpose Of a Coffee Grinder? Do You Need One?


What Is The Purpose Of a Coffee Grinder header image

Coffee grinder is a phrase that gets thrown around a lot when you read about coffee. But you’re not sure what the purpose of a coffee grinder is, how it works and if you need one. Here’s what you want to know.

The purpose of a coffee grinder is to break up whole coffee beans into small pieces so the water can easily extract all the compounds from the grounds in order to brew coffee. Grinding coffee beans just before using them results in better tasting coffee than using pre-ground.

Why is it actually necessary and do you need a coffee grinder at home? You can read more about that below.

What Does a Coffee Grinder Do?

Whole coffee beans don’t brew very good coffee. Throw a few in some hot water and see what happens. You’ll get warm water that’s slightly brown. The water extracts the taste from the coffee grounds which is what brews coffee. With whole beans there is just too little surface area for the water to extract enough of the tasty compounds.

Suggested: Does a coffee grinder make coffee?

That’s why the coffee beans have to be ground up. Grinding coffee is basically cutting the beans into a lot of tiny pieces. This exposes more surface area so the water can extract the taste much faster and easier.

To turn whole beans into grounds, you need a grinder. There are different types of grinders that break up the beans in different ways. There are blade grinders which are basically spice grinders and burr grinders. Burr grinders are much better since they cut the coffee beans into much more similar sized pieces.

Burr grinders have two discs with teeth. One disc is fixed to the grinder while the other rotates. The design of the burrs cuts the beans finer and finer until they come out the other end as grounds.

A blade coffee grinder at work.
Blade grinders do produce grounds but are not the best for good tasting coffee.

Why Do You Need a Coffee Grinder?

Ok, a grinder turns whole beans into ground coffee. But why wouldn’t you just buy a bag of coffee from the supermarket or your local coffee shop? Isn’t that the same thing and a lot easier?

Ground coffee actually starts losing its aromas and the oils oxidize faster. This means the grounds become stale much faster than whole beans and this gives your coffee a flat yet bitter taste.

Coffee beans are full of all kinds of compounds and oils that give your brew it’s taste. You dissolve those compounds in water and drink it. That’s what brewing coffee is. Of course how you brew your coffee makes a big difference in how it tastes but it all starts with the taste in the beans.

Suggested: What if your coffee is ground too coarse?

All coffee beans start out green. They have to be roasted to get their dark brown color. From the roasting process, the beans need a few  days to get to their best taste and will stay their best for about 4 weeks and slowly decline after that. They decline because some of the compounds in the coffee are volatile which means they can evaporate in the air. The oils in there can go rancid through oxidation as well.

With whole beans, all those compounds and oils are pretty well contained and protected. That’s why whole beans stay good for quite a long time. Now when you grind the coffee, you expose much more surface area to the air. This means it becomes much easier for all the aromas to evaporate and disappear. More oxygen also means the oils oxidize faster. Some compounds are more volatile than others so they evaporate faster which is why the taste of the coffee changes.

Coffee tastes best within 10 minutes after its being ground. While pre-ground coffee is usually vacuum packed very quickly after grinding which does prevent some degradation, it’s unlikely you’ll get the absolute best tasting coffee this way.

The only way to get the best taste out of your coffee is to grind the whole beans just before you use them and you need a grinder to do this properly.

You could try using other methods to break up your beans but a grinder is by far the easiest and fastest ways to do it with the best results. Check out the video from James Hoffmann below to see the results of using other methods to make coffee grounds.

Do You Need a Coffee Grinder At Home?

A coffee grinder can help you make better tasting coffee at home. If you need one depends on if you want better tasting coffee. Grinding your own coffee can dramatically improve the taste of your morning brew but it doesn’t come free, there are some downsides:

  • Cost: Coffee grinders cost money. A decent hand grinder can be bought from about $35 while a decent electric grinder costs more than $100.
  • Time: Grinding your own coffee takes a bit of time. You have to fill the grinder, actually grind the beans and clean it. It doesn’t take that much time but it’s more than scooping from a bag of pre-ground coffee.
  • Effort: Especially a hand grinder takes some effort to use. You have to use your muscles to actually break up the beans. An electric grinder takes a lot less effort and is faster but costs more.

In the end it all depends on if you want to spend the time and money to improve the taste of your coffee. Not everyone wants to go through the trouble and if you’re happy with the coffee you make, that’s perfectly fine.

One thing to take into account is your coffee shop visits. A coffee grinder might seem expensive but how much do you spend buying coffee at a coffee shop? If you buy coffee at a coffee shop because it’s better, you can save quite a bit of money. By grinding your own, you can get a lot closer to coffee shop quality coffee and save a few bucks a day. Of course you still have to buy the beans but you’ll be saving money within a year.

Recommended Espresso Equipment

Besides an espresso machine, there are a few other tools that can make your espresso better. Here are my favorites:

  • Espresso Machine: The Breville Barista Express (Amazon) is the sweet spot in price and quality for most casual home baristas. It comes with a built in grinder and most tools you need to brew espresso.
  • Tamper: A nice tamper helps you tamp your grounds in the filter for the best result. Any correctly sized tamper can do the job but a nice heavy one just feels so much better in your hand than a plastic model. This Luxhaus one (Amazon) has a nice trick up it’s sleeve to make tamping very consistent.
  • Beans: Good espresso starts with good beans. Using fresh beans is a big improvement over pre-ground coffee.
  • Scales: Getting consistently good espresso means you have to know how much grounds is going into the machine and how much is coming out and how long this takes. A coffee scale is going to make your espresso much more consistent and also makes adjustments a lot easier. The Apexstone coffee scale (Amazon) is cheap and doesn’t look too sleek but is just as accurate as more expensive scales. The TimeMore scales (Amazon) look and feel a lot nicer but cost a bit more.
  • Distribution tool: After grinding you can get some clumps in the coffee grounds. Those clumps should be broken up so the water can extract all the coffee grounds equally. Distribution tools are very simple things but this one (Amazon) is beautifully made and will look good in your kitchen.

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