Hello all, thanks for your help so far.

I was using a dark roast from Starbucks up until now (their espresso roast) for my shots, and today I ventured out to a different roaster, since I had heard good things about them.

Anyway, this new roast is a "medium dark," and I'm not really sure how that differs.

I used pretty much all the same techniques for the previous roast, which gave a very good consistency to the shot, but with this new roast I'm experiencing a MUCH less viscous, sweeter shot with an extremely weak crema that goes away almost instantly. It's rather strange that the taste is sweeter overall, given a shorter extraction time as well.

From my research, I'm finding that I may have to experiment with:

a) Grinding the beans to a finer consistency
b) Tamping harder
c) Using more coffee???

Not really sure where to go with this.

Do you know the roast date of the coffee you purchased? That would be the first thing to check, in my opinion. Just because it's from a local roaster doesn't mean it's fresh; I know several local roasters that like to keep their bags on display for weeks so that unsuspecting consumers purchase them.

I would be willing to bet that it simply isn't fresh. Failing that, alter one variable at a time to dial in the shot. The grind is the easiest variable to alter for most people, so start with that.

This is all assuming the machine is in working order and it's not an issue with the pump, temperature, etc. since you said your earlier shots were palatable.

Before I'd assume the new coffee blend is at fault and not fresh, especially compared to *$ with it's 6 months from roast best if used by date, check the basics. It's normal to need to change grind or dose with different blends even same blend different days rest or different humidity etc often adjusting grind multiple times during the same day. Check the FAQ this section, maybe starting with The Home Barista's Guide to Espresso.

unclefreizo wrote:...I'm experiencing a MUCH less viscous, sweeter shot with an extremely weak crema that goes away almost instantly.

It could be a difference in blends, especially the change in sweetness. But I agree with Chad, low body and weak crema are signs of stale coffee too.

unclefreizo wrote:From my research, I'm finding that I may have to experiment with:

a) Grinding the beans to a finer consistency
b) Tamping harder
c) Using more coffee???

I agree with (a) and (c). Hopefully you didn't read (b) on this site since it's questionable advice. When I get a new blend, I ask for brew parameters from the roaster (temperature, dose, extraction time, volume). If there's no recommendations, I follow these guidelines:

• Temperature - low (198 or less), medium (200 to 201), high (202+). For the first pull, roast color is as good as any indicator. Darker roast, lower temperature. Once the grind is dialed in, I bracket the temperature to taste what flavors are enhanced (low, medium, high).
• Dose - pour time, grind setting, and dose are related. For a given espresso machine, I start with the dosage that gives the proper head clearance (e.g., Elektra Semiautomatica is 15 to 16 grams, La Valentina is 16 to 17 grams, Elektra Microcasa a Leva is 12 grams, Ponte Vecchio Lusso is also 12 grams, etc.). If the pour is fussy, I reduce the dose and grind finer. If the pours look good but I want to increase body, add a gram to 1.5 grams.
• Extraction time - I don't muss with timers these days, but my pours are probably around 25 to 30 seconds. For ristrettos, I allow a bit longer. I pay closer attention to how the extraction develops than a stopwatch (e.g., even initial beading, even striping, blonds out evenly).
• Volume - brewing ratios are the best for consistency and comparing with others. Depending on the blend and the character I want to emphasize, I will pull them short (higher body, richer, more chocolates) or closer to normales (varietal characteristics like fruit, nuts).

Of course the parameters above are only a starting point.

Please tell us the roast date of the coffee. You are in Seattle, and it should be easy to find freshly roasted beans.

Mike is right.
Given Starbucks' roast policies, the odds are low that this is a freshness issue (though possible).

Every different coffee requires a different grind setting. You will need to "dial in" the grind for each. (in fact, the coffee will need the grind setting changed on a day to day and batch to batch basis as well).
Most coffees are also best with a specific extraction profile (dose, volume of shot, time of shot and the previously mentioned brew temp).

When you change coffees - you need to experiment to find the "sweet spot" for this new coffee (where the flavour matches your desired profile). There are numerous excellent resources on this site explaining how to do this (Mike has provided a good starting point).

Now... not to be contrary or anything but... it almost sounds like you like the TASTE of this new coffee more, it's just that it doesn't have the crema or the mouthfeel of the previous coffee. Is that correct?
One thing to be clear about... some coffees simply produce less crema (or less persistent crema) than others -- and some are syrupy and some are not. This doesn't mean you're doing something wrong per se.

Roast date is 12/22/08, so a exactly a week ago.

I haven't had time to try tinkering with anything yet.

But so then, is a week after roasting going to create freshness issues?

One week past roast should be reasonably fresh. I suspect you just need to grind finer and possibly dose more. Also, be careful to distribute the coffee evenly in the basket, level the tamper when tamping, and if necessary use the WDT (stirring the grounds with a needle or similar implement) to prevent channeling. Once you dial in your technique you should see more crema and body, assuming the blend you're using is suitable for good espresso in the first place.

Stop the madness...

miKe mcKoffee wrote:It's normal to need to change grind or dose with different blends even same blend different days rest or different humidity etc often adjusting grind multiple times during the same day. Check the FAQ this section, maybe starting with The Home Barista's Guide to Espresso.

HB wrote:When I get a new blend, I ask for brew parameters from the roaster (temperature, dose, extraction time, volume). If there's no recommendations, I follow these guidelines:

• Temperature - low (198 or less), medium (200 to 201), high (202+). For the first pull, roast color is as good as any indicator. Darker roast, lower temperature. Once the grind is dialed in, I bracket the temperature to taste what flavors are enhanced (low, medium, high).
• Dose - pour time, grind setting, and dose are related. For a given espresso machine, I start with the dosage that gives the proper head clearance (e.g., Elektra Semiautomatica is 15 to 16 grams, La Valentina is 16 to 17 grams, Elektra Microcasa a Leva is 12 grams, Ponte Vecchio Lusso is also 12 grams, etc.). If the pour is fussy, I reduce the dose and grind finer. If the pours look good but I want to increase body, add a gram to 1.5 grams.
• Extraction time - I don't muss with timers these days, but my pours are probably around 25 to 30 seconds. For ristrettos, I allow a bit longer. I pay closer attention to how the extraction develops than a stopwatch (e.g., even initial beading, even striping, blonds out evenly).
• Volume - brewing ratios are the best for consistency and comparing with others. Depending on the blend and the character I want to emphasize, I will pull them short (higher body, richer, more chocolates) or closer to normales (varietal characteristics like fruit, nuts).

Of course the parameters above are only a starting point.

malachi wrote:Every different coffee requires a different grind setting. You will need to "dial in" the grind for each. (in fact, the coffee will need the grind setting changed on a day to day and batch to batch basis as well).
Most coffees are also best with a specific extraction profile (dose, volume of shot, time of shot and the previously mentioned brew temp).

When you change coffees - you need to experiment to find the "sweet spot" for this new coffee (where the flavour matches your desired profile).

unclefreizo wrote:But so then, is a week after roasting going to create freshness issues?

No, most coffees used for espresso peak between day 4 and 7, though some are great beyond that point. Why coffee needs to "rest" before making espresso elaborates on this point. As an example, Counter Culture Coffee used to recommend four days for degassing. Lately they're recommending 7 to 9 days; in other words, it changes with each crop and blend. Two common signs of "too fresh" coffee are buckets of crema that fall flat in less than a minute and the taste of baking soda.

Thanks for the links and info, all.

I dosed more during my session today and ground finer, and that seemed to help.

The crema came out looking better today, but consistently really yellow/tan looking, though there were some nice looking striations. It wasn't the darker mottled, marbled look that I generally hunt for, however.

Underextraction still?

How did it taste?

It tasted about the same to me, now granted I don't have the most discerning of tastes. But I did notice a definite difference between beans. This medium dark roast is definitely much more mellow and sweeter. It does still have the bitterness common to a lot of coffees that I'm trying to get rid of, but I think has to do with my tendency to underextract. I'm thinking about trying letting the first 1-2 seconds just run into the tray and then putting the cups under.

It's a little bit hard for me to watch color as well, since my portafilter has a black plastic bottom with two tiny little holes. I'm thinking about getting a naked portafilter. Obviously this has nothing to do with over/underextraction, but maybe it'll help me cut at the right time.

Under extracted tends toward the sour and weak, over extracted, channeling and high temperature tend to favor bitter. Odd about the dark roast, I always found dark roasts to be ashy and flat with the lighter having more origin flavor and sweeter. Once you get past full city the roast flavor overpowers the origin flavors, which is why most dark roasted coffee all taste the same. The soul has been cooked out of the beans, but there is an occasional exception.