Just to add a few details on the metal effects that...

It would be the acids in coffee (and held in the coffee oils) that can interact with metal components. (Similarly with a metal knife to lettuce, vs. a ceramic knife, which is a well known example.) In coffee there are some 4 dozen acidic compounds, including citric, malic, lactic, pyruvic and acetic acid as the more concentrated ones; there's also phosphoric acid; and yes they're all in small amounts. Chlorogenic acids (group of acids present in coffee) make up 7% of coffee in dry weight. There are some 800 aromatic compounds in coffee. It's possible for metal ions to be a catalyst for oxidization for certain compounds. I don't know much on the chemistry of volatile compounds, but in observations I do find that metallic tastes can come in at times (such as in grinding, as stated on the home-barista webpage on grinding), dirty equipment (bottom of portafilter when dirty turns the shot black and awful) where some interaction with metal is having chemical effect. Apparently there's less/no interaction between high grade stainless steel and acids. Most quality equipment would have higher grade stainless steel so the acid issue should be minimum; although grinder burrs need to be hardened somehow (as SS doesn't stay sharp) and do strike the surface of the grinds at high speed. Ceramic burrs offer the possibility of no interaction with the acids and other compounds in coffee, and I'm anticipating a difference.

You forget that the burrs get coated with a layer of coffee oils, limiting the interaction between coffee and the steel.

coconut coffee guy wrote:Just to add a few details on the metal effects that...

In your first post you indicated that you were waiting for reviews before "shelling out $400" for a grinder. However, your subsequent posts present a theoretical argument for the new technology. The rationale for the new technology would seem to turn on whether or not it provides a better cup. Perhaps as the new units arrive and are tested against their "metal" counterparts we will have a better sense of that.

It's here...... very well packed by Chris Coffee. It's certainly a quiet grinder. More once I get a chance to use it tomorrow morning.

Mark

Whoa, I thought this was the FIRST LOOK Vario thread. Metal contamination of coffee and particle size distribution sure doesn't seem to fit the subject line. Perhaps we would get more feed back about the grinder (FIRST LOOK) if there wasn't so much pre-arrival baggage.

Nicholas, it's a triple basket and I don't measure weight just volume, the basket is full at 20.5 second so I added .5 seconds to give me a little leeway. Had to make the grind a little finer, the right lever is at the top and the left is 6 up from the bottom. Expect I'll have to adjust the grind depending on freshness of the beans.

Just a FIRST LOOK here guys, no microscopic examination of the particles or a mass spec analysis of metallic contamination.

Bill

flathead1 wrote:Just a FIRST LOOK here guys, no microscopic examination of the particles or a mass spec analysis of metallic contamination.

Wimp.

Nerd

Picked up one of these for my son. Came nicely packaged. However, while each button pushed yields a blue light, there is no grinding. Just a bad unit, or am I missing something?

Hal,

First is the bean hopper fully turned? I found it took a lot of torque to get it to turn and engage the safety switch. If it is fully turned try pushing the manual button first then the start button or one of the three bottom buttons and then the start.

Yep, I just checked the above button sequence on mine and got grinding.

Bill

Bill,

Thanks much! That did the trick. Actually rotated a little too far finally, then had to back off just a little.