I've been grinding my own beans for more than a year using Hario Mini Slim Pro, a manual burr grinder. Before that, I used to order pre-ground coffee.
Recently, I started to wonder, why did I never consider grinding my beans on a blade grinder. After all, French Press requires a coarse grind, my mother's chutney maker can do that too. Should I have used a blade grinder in first place? Am I missing something? Did I really waste my money on a burr grinder?
With all these questions in mind, I decided to go ahead with this experiment. And I've to say, moving on to grinding beans fresh on a burr grinder was the best decision ever!! Why do I say that? Keep reading to find out.
Why do we need a coffee grinder?
Grinding coffee beans just before you brew your cup will make an enormous difference to the quality of your cup, compared to buying pre-ground coffee. Coffee once ground, starts oxidising, leading to stale taste, in just about 15 minutes!
Blade (chutney maker/food processor) vs Burr Coffee Grinders - what's all the fuss about?
Blade grinders have a metal blade attached to a motor that spins and smashes the coffee to pieces. This produces some very fine powder and some very large pieces. When you brew coffee which has been ground like this, the fine powdery parts will quickly add a bitter flavour to the brew, while the larger rock like pieces will add an unpleasant sourness. This uneven brew will not taste nice.
Burr grinders have two cutting discs either flat or conical shaped, called burrs, facing each other. The gap between them is adjustable and changes the size of the grounds of coffee produced. Because the coffee can’t exit the burr assembly till it is the size of the gap between the burrs, the resulting grounds are very uniform in size. This size consistency of grounds results in a higher quality cup, referred to as a balanced tasting cup.
Burr grinders can produce an adjustable range of sizes, making them suitable for a wide variety of brew methods which demand different grind sizes such as that required for a French press or cold brew as well as for an Aeropress or a Pour-over..
Grind comparison:
Blade Grinder - 5 seconds in the blade grinder
Burr Grinder - Hario Mini Slim Pro - 14 clicks
(Don't) let there be fines - a kitchen towel test
So I've been reading that every grinder produces fine grind particles in the grinding process. A good burr grinder produces less fines. I did the kitchen towel test to check this.
This test involves spreading ground coffee over a paper kitchen towel and then pouring the grinds out. Fine particles tend to stick in the tiny grooves of paper towel this way.
Okay at this point, the eagle eyes amongst you must have guessed which grinder is winning this test - blade grinder produced more fines than the burr grinder.
The Taste Test
Alright, now that all the basics are covered, let's jump into the test which matters the most - the taste of brewed coffee in the cup.
Pre-preparation
For this I used the two batches of
12 gm beans
200 gm boiling filter water
Two French Press (if you only have one - use a 250 ml cup to brew second batch, and use the French Press mesh to filter the coffee)
Difference I noticed
Blade grinder brewed coffee had no body and feels pretty watered down
Burr grinder brewed coffee had very good body.
Blade grinder coffee had next to none taste, the mouthfeel was very flat.
Burr grinder coffee had really good taste, which I experience everyday.
Blade grinder coffee was quite bitter even when it cooled down.
Blade grinder coffee had light bitterness when it was hot (an expected behaviour) and it turned into a delightful cup as it was cooling down
Blade grinder coffee was very bland, and there was not taste to it. It just felt like some coffee water. Burr grinder coffee maintained its taste notes even when it was cooled down to lukewarm.
Conclusion
Doing this experiment has cleared all my doubts, and has validated my decision to opt for a specialised burr grinder for coffee.
As a one-off grinding choice or in emergencies, say when you are visiting a friend or family, a blade grinder can definitely do the trick. But in the long run, a good quality burr grinder - electric or manual, is a must for a consistently tasty daily cuppa and is highly recommended.
If you guys are still reading this, thanks for sticking till the end of this article. If this post has piqued your interest about burr grinders, check out this page with STB recommendations on best manual burr grinders to buy in India.