color of crema and small dots on it???

muzoon

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in our small cafe-chain we use allways freshly roasted espresso beans. the tast is fine, crema is thick and long lasting but it does not have the colour as dark reddish or brownish as good espresso crema "should have". our crema is much lighter. not too light of course but not so dark as can be seen on some pictures etc.

the question is: what influences the colour of espresso crema??? how can i make it darker, redder... is it something to do with roast (degree)? or is it coffee greens..???

other question is: the small dark dots on the surface of espresso crema and there are pretty much of them.
i know the dots are extremely small particles of ground coffee beans that have come throught the filtr holes in portafilter. i have never seen them before on any other espressos except of ours.

can anyone tell is it possible to avoid them somehow and how to avoid them?

is it a purpose of roast (degree) or freshness???

will be wery grateful for the ansvers.
 
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muzoon

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we make at 24-27 sec. and it allways stays in 20-30 sec. tamping is normally arround 20 kilo and is quite consistent. amount of ground coffee is approximately 15-17 g for double espresso. we have tryed different grinders and different espresso machines and with different people preparing the drink but the end result is the same. at the same time when trying other espressos with the same techniques and equipment the result is crema without dots.

but do you know anything about color of crema???
 
Ok, crema colour is influenced by a number of factors. Generally an Arabica or an Arabica rich espresso blend will be redder, or browny red in colour, whilst a Robusta rich or a blend with a high % of robusta will produce a crema of a lighter colour. Extraction plays a part in this rule. A poorly extracted arabica rich espresso will be lighter in colour than a well extracted shot. Indeed roasting parameters as well as the processing method of the bean may play a role in crema production as well. I cant really work out the dots/spots part of the question...would be interested to see some pictures though :grin:
 
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muzoon

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yes, i had that on my mind already. i don´t really know how to insert the picture here... however i see it is possible. i better send it to you by e-mail.
pictures are made from the espresso that is roasted 7 days ago. blend consists of:
Guatemala Antigua Los Volcanes - 30%;
Ethiopia sidamo gr.2 -30% and
Brasil Santos NY 2 Screen 17/18 - 30%
roast is aprox. 20 sec. into second crack. and 14-15 minutes long.
roaster - Probat L5

Alun - go see your e-mail you should find some pictures of the espresso...
 

BaristaTrainer

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When is the last time your grinder burrs have been changed? If has been a while, you may see a dramatic difference in your espresso with new sharp burrs.

Also make sure to flush a small amount of water through your grouphead before putting the portafilter in the group and extracting. Depending on your machine, this may regulate the temperature of the water so that it does not scorch your coffee, which can often produce dark spots. I would doubt that the spots are fugitive espresso grounds.

- matt
 

CafeBlue

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muzoon;
Your good questions with decent specific detail is helping you get useful and well-reasoned feedback from Alun and Matt.

Check out the WBA barista competition score/evaluation sheets for more pointers. Review the all judge's and competitor's information.

Your shot time and dose are in the right range. The tamping pressure is a little on the high side, but of course all these factors are inter-related. If you alter tamping pressure a little lighter (say in the 15 to 20 kilos pressure range), then the grind will need to be a little finer to compensate. You will still want the shot time to be about 24 seconds.

Your beans at a day to 2 weeks from roast date is prime freshness standard, but perhaps it is ground too soon? Some cafe's grind coffee to fill the espresso grinder's dosing chamber, then lose cup quality, aroma and crema due to staling in the doser. Brew immediately upon grinding for best results. That means most skilled baristi will use doserless espresso grinders, or keep virtually empty doser hoppers. That means the barista is essentially filling the portafilter by multiple sweeps of the dosing paddle, then levelling and tamping. You do not mention specifics regarding your espresso machine and grinders. If you are using super-automatic machines, then several other factors may also impact results.

I am guessing, without seeing the shots or at least photos, but here are a couple possible factors to spots. Most likely, the spots are loose grinds picked up on the portafilter spout when tamping. KEEP THE WORKSTATION CLEAN AND CLEAR OF SPILLED GRINDS. When tamping, brace the portafilter rim (not spouts) on the edge of the counter with the spout "dangling off the edge". You may prefer to use a computer mouse pad or a similar rubber pad for a tamping surface...keep the pad clean, then you can place the spout on the pad for tamping, without damaging the spout tip. Your roast may have some beans that are too darkly roasted. [You did not mention specifically, but it sounds like your roast is blended green, then roasted. If so, then it should all be relatively similar brown color, without much blackness - according to your description. If you are blending post-roast, then I might have additional suggestions.] The spots MIGHT be caused by portafilter and screens not clean enough, then some of the deposits break loose and enter the brewed coffee. The spots MAY be desirable characteristics of a well pulled shot, like "tiger-striping" in the crema. Photos would help.

The blend you listed adds up to 90%. Perhaps you meant that each ingredient is 1/3 or 33.3%? Perhaps you do not mind posting or PM the remaining details to me?

The green coffee you listed is all described as reasonably high grade, hard bean, washed process arabica.
Modify your blend - ingredients and/or ratios. Increasing the Brasil and decreasing the Guatemalan should increase the sweetness and moderate the acidity, while shifting the color a little darker in tone. Perhaps 40-45% Brasil and 15 or 20% Guatemala will give you an idea of my meaning.
Adding some natural prep or aqua-pulped or semi-washed coffee would boost the body, fruity tones, and yield a darker color tone. Your green suppliers may have appropriate coffee for you to experiment with. You could try similar coffee to your current ingredients. For example a pulped natural Brasil, or a natural Brasil (arabica, not conillon) at say 15 0r 20%, while you keep the Brasil type 2/3 washed component at 15 or 20%. You could try a similar approach with Ethiopian Djimmah, Limmu, or Sidamo/Yrrgacheffe natural (dry preparation) substituting part or all of the washed Sidamo you use now. Be careful to buy exceptioanlly high grade natural prep coffee, or else the physical defects will de-grade the cup quality with off-tastes (muddy, fermented, moldy, earthy, dirty, murky, etc.).
Modify your roast profile. Even without changing the blend ingredients or ratios, a different roast profile can have significan impact on cup characteristics. Reducing the heat application rate will yield a smoother, sweeter espresso. Hard beans like you are using can easily handle a 16 to 22 minute roast duration in a Probat. The trick is to make the roast take longer by adding heat to the beans more slowly, and ending up with a roast that is about the same color as your current roast (not darker). You may need to adjust burner rate, air flow or damping vanes/valves to make the roast profile changes. You might only need to alter the temperature set-points that you use to switch from higher heat rates to lower heat rates. Roasting for espresso is as much about control and finesse of heat application - as it is about skill in green buying and blending.
You may have heard cautions to avoid "baking" the coffee. "Baked" taste occurs when the coffee takes too long to roast because the heat is too little to maintain a continuously increasing bean temperature. So, stretch the roast time longer, but avoid "stalling" the roast.
Alternatively, you might also try a slightly darker coffee roast - a LITTLE further into 2nd crack.

Lots of possibilities...I hope you try a few (scientifically, vary one parameter at a time in order to control your changes) and let us know what results. I would love to hear your feedback after you try a few things.
 
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muzoon

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Hi Barista Trainer
your suggestion to change the grinder burrs is good idea. last time i changed them was aprox. 9-12 month ago[not a good thing to be frank]... so i did change the burrs but the problem remains.
(as i have mentioned above we have tested the coffee on other espresso machines and other grinders [new equipment]). the problem is that using other espresso beans [not ours] with the same equipment there is no dots and crema is appropriate to the espresso beans i use... :-(
i think the color of our crema and dots come from espresso beas not from equipment...
the dots are, i still think, small particles of ground coffee because i tasted them and the feeling and taste in the mouts is as if you had chewed a coffee beans...

espresso machine we use is La Spaziale NEW ek 2 group
grinder are: A.N.F.I.M

also we tryed our espresso on Faemas newest model (machine is totally new)
and grinder was: compac "espresso"

i repeat the result is the same (lot of dark dots on crema and light crema) despite we use different equipment.

i´ll try to organize the pictures of our espresso shots in to forum so you can see better how it looks

thanks,

Ra
 

BaristaTrainer

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Interesting. I would be curious to see photos of your espresso. I am not a roaster, so most of my input is from a preparation perspective. If you are extracting using the same methods, and getting a different result with only your espresso, I think you are right troubleshooting the coffee itself.

One last thing I would try is experimenting with up-dosing. You are using a La Spaziale, which has a narrower diameter group head. You can actually order a set of raised dispersion screens so that you can dose more coffee into your portafilter. I am not sure who your La Spaziale distributor is but maybe you can call and order these.

Many professional baristas in the US and those who excel in barista competitions are tending to dose closer to 19-20 grams vs. the standard 14-18. This can be achieved by developing a distribution method which slightly compacts the coffee by moving it evenly around in the basket. Other baristas will tap the portafilter so the loose grounds settled a bit, allowing the barista to fit more coffee in. A higher d screen is important so that the coffee has room to expand without pressing against the screen. Often the additional coffee can bring out a darker and ideally sweeter, balanced extraction.

If you are able, please send shots of your extraction, from start to finish.

If you weren't so far away I would have you send me a pound so I could play with it. You may want to get in touch with James Hoffman, the current UK Barista Champion, who I believe also works for La Spaziale as a trainer. He is brilliant.

Good luck.

- Matt
 
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muzoon

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CafeBlue,
here is some more background on my espresso and preparation...
greens are roasted and THEN blended. it is really a 33,3% of each. during roasting i keep the time distance between 1-st and 2-nd crack at 3-4 minutes. You hink it should be longer?

Our coffee preparing (packing: [grinding, dosing, tamping, extracting]) is based on SCAA, SCAE, WBC rules. We clean our espressomachines every end of the working day, backflush is included. So equipment should be without any influence to coffee.
But i think it might be that my coffee has been ground too soon dispite it is fresh or as you mentioned???

And thanks for lots of information on creating or impoving espresso blend. I believe it will help a lot.

If i get some changes on that i’ll let all of you know about...

Ra
 
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muzoon

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Matt,
by the way, James Hoffman trained me for an Estonian Barista Championship in 2006. i visited him in London school of Coffee... :)
in my double basket i fill aprox. 16 g of coffee its extraction time was 21 seconda. if as you recommendated i taped a portafilter and with 18 grams of grounds the extraction lasted for 24 seconds. yes i got the color of crema slightli darker but not remarkably.
into a single shot portafilter fits 10-11 g of grounds. but dots reamin ewerywhere...
and more - dots apear at the very beginning of the exraction (and do not accrue later on). crema at the very beginning is reddish in colour but soon after that and when filling into a shot or a ristreto it becomes light.

Ra
 
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muzoon

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Matt,
if you send me or pm me your e-mail i can send you the pictures. i have them ready to send. to put them up in here coffeeforum it might take a time...

Ra
 

BaristaTrainer

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That is cool that you trained with James, I have a lot of respect for him. I sent you a PM with my email, and will wait to see photos. I think visually it will be a little easier to see what you are talking about.

The visual indicators we talk about in our training are these:

Spaghetti size streams of espresso, no larger.
Dark rust colored crema.
A viscosity of warm honey.

I tend to pull my shots between 25-30 seconds, and at that point I start to see slight blonding of the crema. Ask James about the dispersion screen. I trained for a day with Sauro Dall’aglio a month or so ago, a barista trainer from Italy who works for La Spaziale and I explained the up-dosing issue with him. Immediately they sent us the shorter shower screens, and it helps a lot.

- Matt
 

BaristaTrainer

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Muzoon,

I got the pics you sent, and can see what you are talking about. Your extractions do not look to far off, but I can see where you want them to improve a bit. The color flecking, I am thinking may be a temperature issue. I am pretty sure on the La Spaziale, you have the ability to adjust temps on each grouphead? Try playing with this idea ... Also, experiment with up-dosing a bit, even if it adds a couple seconds to your extraction time.

Wish you could bring some to our barista school and we could jam on the machines for a while. Best of luck!

- Matt
 
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muzoon

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on La Spaziale machines i was told it is possible to adjust the temperature but it did'nt sounded as it would be possible on each group separatelly.
i asked about shorter shower screens and they are not expencive but the transportation is so we will wait until we have lots of other stuff to order...

of course in fewe days we are receiving a new greens and i'm gona try to make some new espresso blends or change some coffee in it and play with percentage...

but i will let you know if some results will apear...

Lots of thanks guys!!!

Raimond
 

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