crema solid tone vs. dark to light rich speckled tone ?

#1: Post by **jeffg** » December 22nd, 2007, 4:17 am

I am trying to figure out what causes the different properties of crema surface. I have noticed that when the surface of my crema is richly varied with dark and light the shot is superb but if the crema is one medium to light solid tone the shot is average. Is there anything in particluar that influences the crema? Temp, boiler pressure, brew pressure? If I am getting this solid tone what can I do to get my crazy rich crema back, i've lost it! Thanks

#2: Post by **MaxibonNL** » December 22nd, 2007, 6:21 am

I was actually looking for a similar explanation. Hope you don't mind me tagging along on your post.

My crema has a thin dark ring, even light brown center and lots of dark brown spots. But if that's what you're intentionally after, I wouldn't recommend it. Somehow I feel the crema should have an even texture, no spots.

#3: Post by **MaxibonNL** » December 22nd, 2007, 6:23 am

check out SweetMaria's Crema! A Sign of Good Espresso, or a Symptom of Bad Espresso.

December 22nd, 2007, 2:33 pm

That's a great page with the pictures of different results - I've never seen that page before. I guess Sweet Maria's has so much info that you can almost always find something new there.

#5: Post by **timo888** » December 22nd, 2007, 4:20 pm

Tiger striping and flecking can mean you're in the sweet spot -- or that your cup has been overextracted. It depends on the depth of the roast. If you are using a very light espresso roast, you can get good crema that is quite light in color (persimmon/almond); then, as an index into the quality of the extraction, you would judge it by its density, texture, and persistence, rather than by its darkness or flecking.

Example of very light roast: Barefoot Redwood
Example of very dark roast: Caffe D'Arte Taormina

Regards
Timo

December 28th, 2007, 5:28 pm

That page is getting me back on track. I am now grinding coarser, adding more coffee and tamping harder. I'm getting a richer looking shot with a few flecks but not many and the coffee is lacking some flavor. So two things 1) i can't add anymore coffee 2) i can't tamp any harder than i am. So I am trying to figure out what steps to take to produce some more flavor, it seems my variables left are beans (which are good as the local cafe makes great drinks with the same beans i am using and i know they are a few days out of roast), boiler temp, boiler pressure. My domobar super currently hits 11 with the blind on and the roaster that sold it to me said to take it up to 12 which i haven't tried yet, and some here say to keep it at 10! so not sure what to do, i think with my big dosing and hard tamps anything under 11 will choke? So many variables but I am keen to experiment and find the sweetspot so open to suggestions! Thanks

#7: Post by HB » December 28th, 2007, 7:10 pm

jeffg wrote:My domobar super currently hits 11 with the blind on and the roaster that sold it to me said to take it up to 12 which i haven't tried yet, and some here say to keep it at 10! so not sure what to do, i think with my big dosing and hard tamps anything under 11 will choke? So many variables but I am keen to experiment and find the sweetspot so open to suggestions! Thanks

Pulling espresso at 12 bar is really, really high brew pressure. I would drop the pressure to 10 bar (which will be around 9 bar at the grouphead, IIRC), grind a lot finer, and tamp around 30 pounds. The Buyer's Guide to the Vibiemme Domobar Super and the associated Bench thread has a lot of information specific to your espresso machine (sample excerpt below). In our usage, Dave and I found the Super performed best with a dose around 15-16 grams. Updosing led to increased channeling. I recommend using a bottomless portafilter to confirm the extraction beads evenly and ends with even striping.

cannonfodder wrote:I find the single shots from the Domobar Super to be comparable with other E61 vibratory pump machines. The singles tasted a little sweeter and brighter than the doubles with a creamier mouthfeel. A good shot and well worth the work.

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(and a double espresso)

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HB wrote:Today is a national holiday and my loving wife generously offered to keep the kids occupied while I made a few videos. In the spirit of Dave's Dialing in a new espresso machine, a step by step guide, these are the first three shots of the day. To save you the sound of kid chaos in the backgroud, the audio tracks were removed.

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Lots of nutty flavors from Intelligentsia Kid O's Organic Espresso, but the finish was a little bitter and the roast notes higher than I prefer for straight espresso (however it would undoubtedly make an excellent macchiato). Lately I've been playing with downdosing to improve the nuance of a blend; below is my second attempt with less coffee and a finer grind. The dose is 15.5 grams, which is below the rim for Faema-style baskets. To downdose the grounds, I curved my finger downward into the basket while redistributing, a modified Stockfleth's Move of sorts. It pours a little faster than the previous extraction:

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The nutty flavors remained and the finish was much, much smoother. The roast notes also subsided; a very enjoyable espresso. To finish the series, I coarsened the grind ever so slightly and kept the dosage the same.

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The taste profile didn't change noticeably, but the body decreased, in part because of the coarser grind, in part because I let the extraction run a couple seconds too long. The second espresso of the series was the best.