blog from the ceo & superbarista of phoenix coffee, home of the best baristas in cleveland, ohio

Friday, June 09, 2006

The mystery of dark flecking

I figured it out. Who-hooo! I now know the secret of the dark flecking that is required in order to score anything over a "2" in a barista competition. At least I figured it out on an Astra machine. On our Astra Gourmet machine, that we have at our training center at our Roastery, in order to get a crema that has all three required colors in it, you have to use a bottom-less portafilter. And voila, dark flecking.

The colors that are required are hazelnut, dark brown and reddish reflections. The "dark brown" refers to the elusive dark flecking.

I stole this picture from James Hoffman's blog, because it illustrates the colors I'm talking about.

I was practicing pulling shots with Caitlin and Meri at the Roastery and we got it, thanks the "naked" portafilter. It's so sexy watching the shots out of this thing, too.

Alba at Astra told me that the naked portafilters that they made for their machines because I asked for them have been selling like hotcakes! I thought that was cool. Now I need to get them in use at all of our stores. Because that's apparently the only way we are going to get dark flecking. We can get the hazelnut and the reddish reflections, just fine, but the dark flecking has been baffling me. Especially today at the Superior Ave cafe. All the shots I pulled had pretty much monochrome crema. Bummer. Maybe it's that machine, I'm not sure. It's the Saeco/Gaggia.

The other exciting thing that happened today is that I got a complementary Duet tamper from Reg Barber. I brought it to Lee Road with me immediately and tried it out. Yowsa is that thing sexy! Reg and his crew turn each tamper by hand on their lathes in their shop in British Columbia. So cool. It feels like something that was made with love.


Anonymous James Hoffmann said...

Glad you like the picture!

I've become convinced it is to do with roast style, dose and with the height from pf spout (or lack of it) to cup.

I've yet to have a good explanation...

9:26 PM, June 09, 2006  
Blogger Sarah Wilson-Jones said...

I'm just glad you don't mind that I stole it! Thanks! Nice work on your blog by the way, I'm really enjoying it!

For other readers: you can link to James' Blog through the "Cutie UK Barista Champion" link on my blog list to the left.

7:06 AM, June 10, 2006  
Blogger Sarah Wilson-Jones said...

Oh, and another thought on the dark flecking... if you think it has to do with lack of height from the portafilter spout, and I discovered that lack of a portafilter spout helps, then maybe what we are finding is that the less you disturb the crema as it pours, the better the flecking will be. If the dark flecking is the most sensitive, maybe you lose it when the espresso has to fall too far or when the espresso is routed through the spout. Maybe my spout was dirty, too, and that might make those sensitive flecks stick to the sides of the spout or something.

7:10 AM, June 10, 2006  
Anonymous James Hoffmann said...

no - I meant you get more when it falls further, which would explain why you get it with the naked pf which has a much longer drop to the cup.

What was weird was when I was using the same coffee roasted by two different people, and the quicker and darker roast seemed to have more flecking on the pour. (It was the BSCA #1 blend that they produce as a green blend).

Thanks for the link!

9:49 AM, June 10, 2006  
Anonymous Mark said...

Here's where I differ from James.

I've been fortunate enough to get this kind of tiger mottling on shots from a wide variety of machines, including, but not limited to,

Rancilio Silvia
Solis SL-70
Elektra Micro Casa a leva
Nuova Simonelli Oscar
Pasquini Livia (in fact, my first ever shot showing this effect came back in 2000 from that machine)
Innova Arc
Francis! Francis! X3
Nuova Simonelli Aurellia
Krups XP4020 (no shitting)
Gaggia Classic
Gaggia Carezza
KitchenAid Proline

and of course, the La Marzocco.

I don't agree it has anything to do wit the roast style, because I've gotten tiger striping (the strips of dark and lighter crema in the pour) and tiger mottling from a range of roast styles from City to light French.

I don't agree with it being really about the dose, because with these variety of machines, dose in a double is anywhere from 14g to 21g - some updosed, some not.

I don't agree with the height to the PF spout, because well, all the above machines have widely different heights.

True story: Back in 2000 or 1999, I was bragging on that I was getting a cm or more of settled crema on some shots, after learning to home roast and really tweak my prep style, and timing on the Silvia (this is before temp surfing was a popular term, but I was doing it without a name for the technique, on the Silvia. Some of my more, uh, happy detractors called bullshite on me. So I posted some photos, sequences of the shots being poured into shot glasses, complete with time stamps to show the process. After 30 seconds or so after the shot pour, one could see roughly a cm of crema in both cups. Then I was accused of using robusta. Which I was not... ;)

BUT... in one of the other sequence photos I took to show the settled volume of crema, on top, there was tiger mottling, which by that point, I had become used to seeing on my rare better shots. All sorts of interesting people were asking "what are those spots on top. I was shocked to find out almost no one had ever seen this, or seen textured espresso shots like that.

My theories on why it happens? As stated above, I think it's a sign that the barista has crafted a very good environment for optimal extraction. The spots are undisolved oils and lipids from the coffee. To get them, all it takes is using beans when they are at their literal best, knowing your machine's temperature abilities (and playing off them if you have to, like brewing right at the end of a boiler cycle, or similar), matching your grind to your dose, making sure everything sizzles with heat, etc etc.

2:10 AM, June 11, 2006  
Anonymous Mark said...

PS... not to brag tooooo much (lol), but here's some examples - many from the LM, but a few from other machines. All sans the naked PF.

Honey'd espresso (brewed right into the cup)

Start of a shot - the texture is packed:

Double showing lots of mottling, in two cups

Krups exhibiting a tiny bit of flecking (not bad for a studio shoot - got lucky)

And this dark and settled monster was pulled on (IIRC) a Vibiemme Domobar machine

I just realised that in my photo repetoire, I don't have many photos of the streams during a pour. Inspires me to set something up soon to capture that.

2:21 AM, June 11, 2006  
Blogger Sarah Wilson-Jones said...

Thanks, Mark!
Those are some great observations! And I'm glad to know that I'm not the only insomniac, judging by the time of your comments. Many of us coffee people just drink too much (coffee that is). :)

So maybe we are heading more to the conclusion (if there is one) that the dark flecking has more to do with uniformity of pack and extraction, and a certain gentle handling/packing of the ground coffee.

This is why I love espresso. When it comes down to it, we can't analyze EVERYTHING, and some of the process will always have to be attributed to the pure, raw intention and skill of the barista. Not everything can be explained. The real skill just has to be learned by practice and devotion to the craft.

9:48 AM, June 11, 2006  
Anonymous james hoffmann said...

Mark - sadly I am going to have to disagree with you on what the spots are.

I think it is highly unlikely that they are oils out of emulsion. You would see crema disappearing from those spots out as the oils screw with the surfactants in the foam. (But this is no place for a drawn out discussion of foam theory!)

I think it is more likely that they are fragments of ground coffee in suspension on the foam. Hence I think roast does have something to do with it.

I've gotten it on all sorts of machines, on good shots and also the bad.

1:18 PM, June 11, 2006  
Blogger Sarah Wilson-Jones said...

I'd love to hear the foam theory stuff! Would you like to do a guest post on it? Or maybe do an entry about it on your blog and I'll link to it. Dennis, our Espresso Wizard, has been trying to get me to read this book called "Foam" for years now. Maybe its time for me to dust it off and actually delve into it. Although I think he recently borrowed it back from me. :)

7:12 AM, June 12, 2006  
Anonymous james hoffmann said...

I am working on something for my blog.

Is it "Foam" by Sidney Perkowitz? Its a nice introduction to the basics of foams, though not overly relevant to espresso. In fact the milk section is reasonably wrong! But still - short book, well worth the read.

5:24 PM, June 12, 2006  
Anonymous Mark said...

Heya James...

Not quite sure why oils would screw with crema as you suggested. After all, isn't crema just emulsified oils itself? It's definitely not foam in the normal sense (ie, liquid aerated); I'm no food scientist, but I do know about the whole oil on soap foam trick (ie, it will immediately move the foam), but the stuff on coffee isn't the same thing?

I've heard many say it's actually solid, powdered coffee that made it thru the basket's filter holes. Not so sure about that myself - after all, with that argument, one would probably see more of it from a blade grinder (which produces lots of dust) than any other grinder? In fact, from my experience (again just experience, no food science applied - I suck at science anyway), I seem to get tiger mottling more often from the better grinders in my stable than I do from the cheaper ones. Better usually equals more even grind, with little "dust".

3:16 AM, June 13, 2006  
Anonymous james hoffmann said...

Actually Mark I'd say that that is exactly what crema is and is not emulsified oils.

First draft of my foams post is up - let the arguments rage!

9:01 AM, June 13, 2006  
Anonymous Mark said...


tiger mottling via, of all things, illy coffee. Woot ;)

9:22 PM, June 19, 2006  

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