Light roasted shot struggling

[snedden9485]

After some advice regarding a coffee I recently had in the grinder. It was a light roasted specialty kenyan which was roasted for espresso, but was definately on the lighter side of roasts.

I run a Linea Mini and compak E5OD grinder, weigh in my shots and distribute via OCD. Brew temp around that 94 - 95c mark as it was a lighter roast. I run VST baskets and precision tamp, I almost never have any sprays or chanelling on the bottomless portafilter, but I was struggling severely with this one. I would get an OK extraction for maybe 7-8 seconds, then a very light watery style crema with pinholes starting to spray. I played with the grind and went finer, It helped a little, but still started to squirt after the initial saturation came through. I must have pulled 7-8 shots, all much the same. Taste in the cup was ok, naturally a little under extracted.

Any ideas on what this could have been? Is it more likely a coffee that was too light for a sufficient espresso extraction?

Since I have went back to some of my roasted coffee and some others and almost perfect extractions!

interested to hear peoples thoughts.

[Yelta]

After some advice regarding a coffee I recently had in the grinder. It was a light roasted specialty kenyan which was roasted for espresso, but was definately on the lighter side of roasts.
Any ideas on what this could have been? Is it more likely a coffee that was too light for a sufficient espresso extraction?

Since I have went back to some of my roasted coffee and some others and almost perfect extractions!

interested to hear peoples thoughts.

"Since I have went back to some of my roasted coffee and some others and almost perfect extractions!"
Sounds like you have the problem sorted Snedden, Perhaps the Kenyan beans we're roasted a little light for espresso, or, perhaps simply not to your taste.

Time to start home roasting???

[Melbroaster]

Because of the group architecture of the LMLM it is less forgiving of lighter roasts, older roasts and dosing/distribution flaws. If your beans are fresh, then you may find that a lighter roast will highlight a small imperfection in your basket prep approach that would be hidden by a darker roast which itself tends to be more forgiving.

I suggest looking at the steps you take prior to pulling the shot to see if there is anything that can be improved.

[snedden9485]

I would like to think my dose, tamp and distribute is pretty spot on as i weigh in, flatten dose, distribute with OCD and then tamp.

It was certainly a frustrating time!

[Yelta]

Because of the group architecture of the LMLM it is less forgiving of lighter roasts, older roasts and dosing/distribution flaws.
I suggest looking at the steps you take prior to pulling the shot to see if there is anything that can be improved.

Hmmmm, what can I say, sounds remarkably similar to the VST basket story, much better baskets! simply that most people find them difficult to use.

Interesting that Snedden is also using VST baskets!

[samuellaw178]

It is possible that the coffee is (warning: jargon ahead) severely underdeveloped in roast and is not soluble enough for espresso. I've had that kind of roast in the past. Best leave them for filter - they're probably not that good either because of the under-roastedness. Makes tea-like coffee - that'd be a sign.

The basket is never the problem, despite slightly more demanding (which is a function of grinder, and secondly sound technique) to get a picture perfect pour .

[TampIt]

I would like to think my dose, tamp and distribute is pretty spot on as i weigh in, flatten dose, distribute with OCD and then tamp.

It was certainly a frustrating time!

You didn't state the age of the roast.

First test: break open both a smaller and larger bean and check that they are roasted correctly. Both roasted all the way through? If not - bin the lot. Unfortunately a very common problem amongst some of the "third wave mob" which gives the rest of them a bad name.

Assuming it is roasted correctly then it is probably too fresh. Darks tend to take the traditional "4 to 11 days optimum". Speaking about the same batch of coffee - light roasts are significantly less soluble so you need to grind a lot finer. It also means you must have a better grinder - some trad Italian commercial grinders don't cut it at all*. Light roasts also take a lot longer to run in. Surprisingly often the dark roasts need pallbearers before the lighter ones come on stream.

A simple second test - if it still smells green, it is. Also, if you are a crema addict, you will never get the same quantity of crema out of a lighter roast compared to a dark roast from the same batch. Mainly related to the age factor. The compensation - a good light roast has (my opinion only) way better crema quality and a much better, more lingering aftertaste.

Baskets: Considering I have trained numerous newbies and they NEVER have VST problems (even in $800 "grinder + machine setups") and they are also the official world barista basket over the last few years, I think the poster that suggested they are a problem should reconsider. He has probably picked up a few bad habits "along the way" and should cease blaming his tools... If a range of people from a newbie to a world barista champion can use them, they seem to have most bases covered! Apart from working a lot better with a flat based tamper than any of the various curved ones, they forgive anything except poor techniques or poor grinders. They are also a useful diagnostic tool in the sense that they reveal shortcomings with lacerating clarity.

Linea: I have played with the big ones a lot over many years (still my fave cafe machine by a wide margin) - the poster that suggested they reveal any issues with lighter roasts is spot on. I guess the mini shares that trait?

Enjoy your cuppa, the rest is just life's dandruff.

TampIt
* I have never used your grinder model first hand, so no thoughts either way. FWIW, most Compak's are pretty good.

[snedden9485]

Thanks guys. Coffee was around 2 weeks off roast, so should have been about spot on for the lighter roast. I have been using VST baskets for around 6 months and have found them fantastic, no real issues at all. Like I said, this seems to be the only real coffee to present any real issues, so im putting it down to the roast.

[davidxcoffee]

FWIW I encounter the exact same issue when using lighter roasts. Not sure why that is either. I've turned to using a spouted portafilter for whenever I want to try a light roast as espresso. Turns out OK but much nicer via filter in most cases.

[EspressoAdventurer]

Sneddon I can contribute some alternative thoughts.
My roast count currently runs into the early 70's.
Having previously only 'toasted' a roast once...
However the opposite occured recently where the roast was quickly binned and def under developed.
If your issue is just that then what I recently experienced the taste
in the cup will certainly tell you so.

I was at a coffee house 'open day' recently where a local roaster of some note was presentiing his schtik on good coffee.
Amongst the many varieties he produces, is a roast / blend that is marketed under the name of 'Fruit .....:
This blend and indeed some of his other roasts have recently been recognised nationally / awarded in consecutive years.
The shots of the Fruit ..... I tasted were pullled on a Bezzera Domus Galatea and alternatively also a Mitica.
Tasted as a 6oz Latte The sweetness and fruitiness jumped up and down on the palate dancing a merry party. Eye opening!
As an indication the roast colour was in the area of CS7...
Yes as it happened I just happened to have a credit card sized CS colour chart with me

Ok so the info that he was happy to discuss with me when a small amount of time was offered later in the day to shoot the breeze and discuss stuff adhoc....
Im sure passing anything on here may be ok, was....

That in experimenting with the blend,their machine ( a San Remo) and a Scace II,
Temps were run as low as 89 deg & up to 93deg. Pressures were lowered away from the std 9 bar and progressively down to a low of 6bar.In his own words it was the lower temp / pressure ranges that delivered the better band of results and brought out the most in this blend / lighter style of roast.

Note I have now reason to believe the Bezzeras used on the day were modified in any way from the std spec that would be sent out into theAust marketplace. And in fact I saw the Scace II on the Domus Galatea and it was running in the std range of 92 deg and 9bar at the Group.
Numerous shots with a variety of roast styles were produced during the day and all that I tasted were exceptional.
So confirming the 'fruit ....' shot that I tasted was pulled under 'normal temp pressure ranges' with a dual spout Handle.
So obviously I have no indication whether it may have 'spurted, channelled or else' etc...but it certainly tasted exceptional given that I had never experienced a shot or taste like this before in a coffee.

Sneddon Hope this info may help.
Best of Luck with your adventures.
EA

Ps The Grinder was a Compak E10
yes he was using the same baskets you are !!
No the beans weren't Kenyan

[muppet_man67]

If the roast is very light you might need to up the extraction by increasing your brewratio. Try between 2.5:1 and 3:1
You'll most likely also reduce the shot time. You'll have a weaker tasting espresso but once you find where it balances out it should still be very nice.