I am a brand new member of those interested in espresso making. I recently acquired some used espresso equipment: a Faema Faemart, and a Mazzer Super Jolly. The first thing I have done is visit a number of cafes that serve espresso, and have had the opportunity to watch their techniques. Much to my surprise, I found that one of the cafes didnt grind their own coffee beans, rather, they have theirs ground by their supplier. I believe that they described their coffee as being a "number two" ground. They even gave me a tablespoon of it to take back home with me. The first thing I noticed that these grounds were considerably finer than I have been able to get from my Super Jolly. Also, the coffee grounds are a pure dark brown. My grounds are lighter brown with flecks of white. I am beginning to suspect that these flecks of white are a result of having dull blades ( I have since ordered a new set of burrs). I find that as I turn the adjustment wheel to make the grinds finer, I come to a point where the coffee grounds do not discharge into the doser. The machine seems to "clog" up. I have to turn the wheel to a much coarser setting for the grounds to finally exit the burrs into the doser. I haven't read anything similar happening elsewhere in the forums. I had originally been concerned that I wasn't able to turn the adjustment wheel anywhere near the zero on the dial without hearing the burrs start to grind together in a very disturbing way!. I was glad to read that this is normal. Since I bought the Mazzer used, it could well have the original burrs in it. Is the fact that I am getting white flecks especially in my coarser grinds, and that the machine clogs up when attempting a finer grind symptoms of dull blades? This clogging begins when I am near 2.5 on the dial.

Made my first latte last night. Not too bad, though I am having trouble with microfoaming milk. I guess it will take practice!

Got lots of questions. Any help would be appreciated.

depshrink wrote:Much to my surprise, I found that one of the cafes didnt grind their own coffee beans, rather, they have theirs ground by their supplier. I believe that they described their coffee as being a "number two" ground. They even gave me a tablespoon of it to take back home with me. The first thing I noticed that these grounds were considerably finer than I have been able to get from my Super Jolly. Also, the coffee grounds are a pure dark brown. My grounds are lighter brown with flecks of white.

That's because your coffee is fresh and theirs is stale. Even after roasting, all coffee has some residual (whitish) chaff; it's easy to see in the little line that separates the two bean halves. When you grind fresh coffee beans, the fragments of the chaff are mixed in with the grounds. However, when it is preground and packaged, the chaff has time to absorb the coffee's oils and discolor, resulting in a more uniform shade of brown. When it comes to ground coffee, perfect color uniformity is not necessarily a good thing.

One of the roaster's at Counter Culture and I were talking about commercial, large scale preground coffee. He pointed out that chaff is lighter and naturally rises to the surface of a heap of ground coffee. He visited a large coffee factory and saw that the troughs of ground coffee had a large auger down the middle to mix in the chaff fragments so the coffee looked uniform to the consumer.

depshrink wrote:I am beginning to suspect that these flecks of white are a result of having dull blades ( I have since ordered a new set of burrs). I find that as I turn the adjustment wheel to make the grinds finer, I come to a point where the coffee grounds do not discharge into the doser. The machine seems to "clog" up. I have to turn the wheel to a much coarser setting for the grounds to finally exit the burrs into the doser.

Have you cleaned the burrs (instructions)? The grinder is used and it would not be surprising if the burrs are caked with oils. It can build up to the point that it becomes a hard resin; not pretty. After you confirm the burrs and chamber are clean, rezero the burrs and then back off approximately 1/8th turn to arrive in espresso grind setting range.

Tip to reduce waste: Learn to adjust the grinder based on the feel of the grounds. A teaspoon is enough to check the granularity and moisture content. Grind a sample and pinch it between your fingers. It should feel much coarser than flour, but less coarse than salt. The grounds should stick together slightly; if the beans are fresh and the grounds don't adhere together, it's too coarse. If the grounds hold a fingerprint impression, it's too fine.

depshrink wrote:Is the fact that I am getting white flecks especially in my coarser grinds, and that the machine clogs up when attempting a finer grind symptoms of dull blades? This clogging begins when I am near 2.5 on the dial.

Signs of dull burrs include finer and finer settings necessary to get a decent pour, uneven grind quality, clogging, etc. Below is a closeup of what flat burrs look like when brand new. You will easily feel the difference in sharpness between your new burrs and the old.


Courtesy of Al Ruscelli's Mazzer Mini Burrs

To determine if you burrs need replacing run a fingernail around the inside of the blade side of each burr (upper and lower) against the sharp ridges. The burrs should shave a thin layer of fingernail off all the way around. Sometimes a worn burr does not have any physical signs of wear (pits nicks etc. . .).

I appreciate the responses. The new burrs for my Super Jolly should arrive Monday. I am anxious to see what difference they make, and whether or not they remedy the clogging I experience on fine grinds. I experimented with a different coffee bean blend today, and was surprised to see the difference between this blend and the blend that I was using previously. At the same grind setting, this new blend clogged the portafilter completely up. Almost no liquid came through. It took four adjustments to the grinder before I zero'd in on the right setting -- 60 ml in 27 seconds.

Although I have only had my Faemart for two weeks, I find that I am experiencing upgrade fever. I saw a La Cimbali Junior that would look good on my kitchen counter....I wonder if my wife would notice if I switched machines !

Thanks for all the help.

A final update on the Mazzer Super Jolly burrs. Well, the burrs arrived and replacing the old ones was very easy. I felt the old burrs and found them to be quite worn compared to the feel of the new ones. The new burrs made all the difference in the world. With the old burrs, I had to set adjust the setting to the finest grind I could without zeroing out, or immediately clogging up. With the new burrs, I get the same grind at the left end of the label, which is a far ways from where I had it set before. That's quite a difference! Also, the machine is not clogging up. I would think that if someone gets a used machine, changing the burrs should be almost routine. They are not that expensive. Thanks again.

Thanks for the follow-up, glad to hear all is back in order.

I've been meaning to post a thread showing exactly how to replace the burrs. It's not hard at all, but a few pictures may convince the reluctant to do it sooner than later. The only "trick" is keeping the bottom burr carrier still while loosing the burr's three retention screws. I wedge a wide blade screwdriver between the side of the grinding chamber and the carrier to immobilize it. A gentle twisting pressure on the wide blade screwdriver is enough to act as a wedge while you use another screwdriver in your other hand to loosen the screws. Apart from that minor detail, the rest of the steps are the same as the cleaning instructions.

HB wrote:The only "trick" is keeping the bottom burr carrier still while loosing the burr's three retention screws. I wedge a wide blade screwdriver between the side of the grinding chamber and the carrier to immobilize it.

It's time to replace you toothbrush, anyway, you know that it is. Four out of five dentists in made up statistics suggest that you replace you toothbrush every three to six months. How long has it been since you started using the one that you're using right now? Oh, gross!
This is a far gentler tool to use to immobilize your lower carrier while you turn the screws. I dunno if tool hardened steel is harder than the carrier or the chute or not, but I'm almost positive that the toothbrush isn't. Oh, and the toothbrush is going to come in really handy when you're cleaning the thing anyway, so replaces all the kids' brushes while you're at the grocery store, and you've got a wide variety of sizes to get all the nooks and crannies. Comes in handy when cleaning the doser out, too!.
Even if you're not at that place where one is required, consider getting a denture brush while you're there. They make a great large surface scrubber, and most of them come with a little pick-type brush that is perfect for cleaning PF gaskets and screens.

Other than that, yeah, what he said. Changing burrs is dead easy. So easy, in fact, that I find it easier to remove the burrs to give them a good spring cleaning than it is to clean them in situ. Remember to dry them really well, though, as they are prone to rusting when they are freshly scrubbed and don't have a thin, protective coating of coffee oils on 'em.