Home > Articles > Coffee Grinders Grinders: Blades, Burrs, or Biceps? Introduction In this article, we explore the different kinds of grinders, along with their advantages and disadvantages.  The three major groups discussed will be automatic blade grinders, automatic burr grinders, and hand crank burr or blade grinders.  So then, let's begin. Blade A blade grinder uses blades to grind.  Sounds easy enough, on to the next topic... Well, there is a bit more to it.  It's true, a blade grinder works like a dry mix blender.  It chops the coffee beans into little bits.  Generally, the longer you grind, the smaller the bits get.  In order to get an espresso grind (if possible) out of a blade grinder, you have to grind for quite some time, up to sixty seconds and sometimes more.  If you want a coarse grind, you are generally going to grind between ten to twenty-five seconds (depending on the grinder).  For most drip coffee makers, you are looking at twenty to forty-five seconds of grinding.  So, the whole process is pretty simple, just grind longer for finer granules.  In addition to simplicity, these grinders are very inexpensive, ranging anywhere from $15.00 to $30.00. Now comes the catches.  And there are a few, but they are pretty significant.  First, the coffee beans get ground relatively unevenly, or in a not uniformed way.  Some large chunks, some tiny ones, and some just right.  So, inconsistency of grind size is one characteristic that is bad.  The second characteristic that is bad is that the metal blades that spin around will heat the beans the longer they are grinding.  Now let's explore these characteristics a bit more in depth. When you grind coffee beans, you are breaking them into chunks so that they can most easily release soluble solids (that's the good stuff) into the hot water used to brew.  The longer the brew time, the larger grain your coffee grounds should be, because it takes that much longer to extract the right amount of oils.  If you use too fine a grind in a process (like percolation) which normally requires a larger grain, you will extract too much of the oils, and your coffee will taste bitter.  If you load up an espresso porta-filter with coarse grinds, the water will come out a very light tan with no crema, because the grounds were not soaked long enough.  The point?  You need the right size coffee grain for the brewing application.  And if blade grinders are notorious for producing inconsistent grain sizes, they may produce the wrong sized coffee grains for your brewing application.  This could result in very strange tasting coffee.  However, to the untrained palate, the larger grains and smaller grains extract oils in such a way as to even each other out.  To the connoisseurs, this flavor results in a characteristic cup we like to call "uneven" or "undrinkable". So that's problem number one.  The second problem, recall, was that there was significant heat transfer from blade to coffee.  To figure out the problem with this just think about what happens when you heat up certain other foods, like vegetables.  The longer you heat them up, the blander they taste, right?  Well, coffee is similar in that the oxidation, which is responsible for releasing aromatics, occurring at a coffee grain's surface, accelerates when heated.  Try thinking of it another way.  We sell a blender, the Vita-Mix 5000, which can make hot soup in less than 10 minutes simply by blending ingredients.  How does it accomplish this? The spinning metal blades generate so much heat that the entire mixture is brought to near boiling temperature.  So, the faster that metal coffee grinder blades spin, the hotter the coffee gets.  Again, to the untrained palate, this is no big deal.  But, chances are, if you are reading an article about coffee grinding, you are a bit more interested than the common supermarket coffee consumer.  All in all, whatever the advantage blade grinders have in terms of price and ease of use are diminished in the face of their significant disadvantages.  To the true coffee snob, a blade grinder is maybe good for chopping up herbs, and that's about it. Burr Grinder Here's how it works: there are two pieces of burred metal, sometimes flat, sometimes cone-shaped, that lie on top of one another (in the case of conical, inside one another).  The metal pieces rub together, beans pass through, and the grounds are mashed out into a hopper or a (doser) chute.  Usually only one of the metal burred pieces moves, but in some models both move against each other. The closer each burred piece of metal is to the other, the finer the resulting coffee grain.  In professional burr grinders, the grinder is calibrated by setting the selector to the coarsest grind, and adjusting the master dial just until it squeals or whistles (this means the burrs are touching, ouch!), and then ever so lightly tapping it back a notch in the reverse direction.  Then the dial is tightened down. Unfortunately, home units, particularly the less expensive ones, are notorious for not being calibrated correctly, or having uneven distances between each burr plate during the grinding.  This, combined with very few, dull, or poorly constructed (made out of cheap metal) burrs, is what causes uneven granule size in burr grinders.  There is debate over which kinds of burr grinders are better: flat or conical.  The debate is "heated" in that the general school of thought is that conical grinders diffuse the heat better, given the shape, than flat burr grinders.  Most burr coffee grinders can really get up there in speed, some edging on 1500 rpm.  The flat grinders are the ones preferred by massive coffee packaging companies because of the convenience. In my opinion, for home use there really is no great difference between the type of burr grinder you use in terms of the finished product.  Generally, the burrs in a grinder under one hundred dollars will produce a grind less consistent than a professional burr grinder and much more consistent than any blade grinder.  The burr grinders over one hundred dollars usually have more metal in their guts and the burrs are sharper and more precisely set.  Furthermore, they have a sturdier burr assembly, which means you can adjust the fineness... well, finer, and the burrs will actually stay where you set them.  So, if you are grinding for an espresso machine, do yourself a favor and purchase a top-of-the-line burr grinder.  Manual Crank Grinders -- Biceps Okay, truth be told I just wanted another the third "B-word", "bicep", in the title.  This category is actually a subcategory of the blade or burr grinder category.  The only difference is that the driving force is not an electric motor, but your arm, which cranks a set of blades or burred plates.  However, since most quality hand crank grinders are built with a minimum number of parts, they will outlive most electric burr models for under one hundred dollars.  Even better, and this one is VERY important to me, most of these grinders AREN'T PLASTIC!  So, the grounds hopper doesn't get that staticy mess of grounds all over its walls or your counter.  Most of these units have a wooden or porcelain grounds hopper.  The drawback is the work.  And most manual grinders come with only one grinding range: automatic drip.  But, if you have the time and energy, the grind from one of these quality mechanisms will be much more consistent than both a blade grinder and an entry level electric burr grinder. All in all, for serious coffee drinkers, a burr grinder is the way to go.  And, in the past two years, great leaps have been made in burr grinder technology.  But there is still a ways to go, and that way focuses primarily on robustness of the burr assembly.  At the end of the day, though, even a shoddy burr grinder beats any blade grinder.