finer or coarser settings on roast profiles

joe jeczen

Hello,

I've been looking all over the net for new beans since I talked to a relative of mine that is even more of a coffee geek than me.

He might even start his own roasting business..

Anyway, since I've started my shopping I'm realizing that a lot of the new "west coast (usa)" roasts and other really popular coffees for espresso have medium to medium-light roasts.

I really struggled with Kenya AA from Londinium to get a good shot, I ended up using it in press pot, which made a beautiful cup compared to my espresso venture with it.

My question is what good fundamentals do you guys use for these new light roast espresso blends? i.e. grams per dose? finer or coarser compared to darker roasts?

Any of your input would be great!

Kfir

I would go finer and lower the dose a bit to compensate.
A light roast will be unbalanced sometimes leaning towards acidity and less body and grinding finer with a lower dose will help to balance it a bit.

BTW I don't think that light roasts always work well in espresso, a Kenyan may indeed work better in drip or FP...

Kfir.

Unknown

I roast to City+ to FC, and on rare occasion FC+. If I roast decaf for my wife, and my late afternoon coffee, I roast that to FC+ or maybe a wee bit darker.

How to describe the density of the grind??!!? Pretty fine is all I can say. 10.5g for the decaf singles and 15.6g for the regular doubles. On rare occasion I will drink a milk drink and I does it 18g in the 21g basket(espresso parts). I do not adjust the grind for each different roast and I try to only roast enough so the age of the beans is not messing around with the pour to badly.

Last week I started trying to blend beans after I roasted them. WOW, did that turn out great! Thick and full of sweet. 2/3 Guatemalan Huehuetenango roasted to FC+ and 1/3 Guatemalan Geisha roasted to FC+. I am going to try to do that again because it turned out so well. Beans sourced through Sweet Marias.

I used the same grinder setting for that blend.

Gino Magnotta

Agree with kfir. You want a finer grind with a lower dose to extract more sweetness/caramels. Pull a slow gloopy kind of shot.

Reiss Gunson

joe jeczen post=1672 wrote: Hello,

I really struggled with Kenya AA from Londinium to get a good shot, I ended up using it in press pot, which made a beautiful cup compared to my espresso venture with it.

My question is what good fundamentals do you guys use for these new light roast espresso blends? i.e. grams per dose? finer or coarser compared to darker roasts?

Any of your input would be great!

for the lighter roasts you need to make sure you have your pressure stat set correctly for the ambient temp - i.e. you need to have the group hot enough - this tames the acidity and draws out the sweetness.

as always, be sure to pull the PF immediately after the shot, knock the puck out, rinse the PF by putting it loosely in the group and quickly jiggling the PF handle left and right as you do a very short flush

if you religiously follow that simple routine it does not then matter how long before your next shot - you should be able to walk up, load the PF with no flushing, and pull the shot. if you are not getting some chocolate brown flecking in your shots it is unlikely that the extraction is hot enough.

Dan Streight

I've also found, oh God to bring up the p-stat thing again , very light roasts tend, in general from my experience, to prefer higher water temp. Whereas my medium to dark roast blend is happier at a bit lower water temp.

And like others I've found lighter roasts need finer grinder setting and lower weight in the basket. Also I've noted a difference in the volume of the grinds, even at the same bean weight, between light and medium-dark roasts.

Another factor I haven't found an explanation for: The wide difference amongst different roaster's offerings and how each varies from a very short window for peak flavor to an extended range for peak to near peak flavor. I just tried, after reading accolades on HB about a new-ish San Francisco roaster, and had God and near God shots at 5 and 6 days post roast; thereafter the taste fell to the toilet or nearly so . Whereas other roaster's offerings, including my stalwart Adventure Coffee Roasting out of Tucson, go 2-3X for peak/near peak flavor (sealed container, stored at ambient room temp for short term drinking).

Kfir

Leave the pstat as is and try this as well:

1. Light roast - short PI (< 5sec).
2. Dark roast - long PI (> 10 sec).

Kfir.

Salvatore Taibi

Kfir,

I'm curious, wouldn't a longer PI be subjecting the darker roast to higher temp? At first glance, I would think it would be the opposite: i.e., long PI with lighter roasts. This is something I have not played around with, but will certainly try in the future.

Thanks,
Salvatore

Gino Magnotta

You would think so but it doesn't. The longer you preinfuse, the cooler the water gets as the cooling effects of the group take hold. Make sure you flush well after a long preinfusion as the thermosiphon is likely to stall.

Kfir

Gino Magnotta post=1687 wrote: You would think so but it doesn't. The longer you preinfuse, the cooler the water gets as the cooling effects of the group take hold.

My thoughts exactly!

Kfir.

Salvatore Taibi

I understand this rationale, but aren't you still subjecting the coffee to super-heated water for an even longer duration? I don't claim to know for certain, but I would think the longer you let the ground coffee "bathe" in hot water... whether it is 86 deg or 88 deg... the higher it is progressing above it's ambient temp.

I haven't focused on the group temperature part of the equation, but rather the temperature of the coffee itself. Again, just trying to understand what is taking place. Thanks for the great information!

Gino Magnotta

When you preinfuse, the coffee puck swells and reforms. Assuming no coffee comes out, very little extraction occurs at this point and the rest of the group fills up with water. This water cools the longer it stays in the group. Extraction of coffee only really occurs when there is a blast of enough volume of water delivered under pressure. In a lever this pressure is provided by the spring. In a short preinfusion the water delivered under spring pressure is hotter than if the preinfusion was longer, where that same water has cooled a little.

Makes sense?

joe jeczen

I'm really liking this topic here guys, a lot of great info from you guys on PI times is extremely helpful.

So is there anyone that can tell me what bar they adjust their pstat to for say the Londinium Kenya AA for an optimum shot?

I read the pstat adjustment thread and it seems that the lower the bar the higher the temp? I know this question sounds stupid, but that's what it looks like in the values posted by Reiss.

Also, I think the factory setting is 1.1 - I'm not certain of this, but I've only had my L1 for a few months and never adjusted the pstat it has always read 1.1

Dan Streight

joe jeczen post=1695 wrote:
I read the pstat adjustment thread and it seems that the lower the bar the higher the temp? I know this question sounds stupid, but that's what it looks like in the values posted by Reiss.

Also, I think the factory setting is 1.1 - I'm not certain of this, but I've only had my L1 for a few months and never adjusted the pstat it has always read 1.1

Joe,

Turning the p-stat adjuster clockwise increases the boiler pressure/p-stat spring tension. This has the effect of raising the pressure in the boiler resulting in increased BAR. Adjusting the p-stat by turning the adjuster counter-clockwise has the opposite effect.

Without knowing more details I would say your current setting of 1.1 BAR is a little low. If your shots taste consistently sour then try increasing the BAR to 1.2...or go by Reiss' chart.

Cheers,

Dan

Reiss Gunson

hi joe

i think you need to keep it simple - i do not change the pstat for different roasts - all i am saying is measure the temperature of the room in where your L1 is (not above it or right beside it obviously, but say 40" away/metre)

and secondly i was just flagging up the need to promptly remove the PF, empty, & a quick rinse in the group

you may have a constant temp where you have your L1 year round - i simply don't know - bear in mind these machines are all over the world in a vast array of climates & set-ups. for example our kitchen was 28C this summer, but i let it drop to 15C in winter, and that is a huge shift which means i really should put the TS restrictor in 28C (but i didn't because the hot weather doesn't stay with us for more than a week, or two if you are lucky!) and i am now running at 1.5bar in 15C, which incidentally works very nicely indeed!

that kenyan was one of the best roasts we have ever offered, assuming you like something with a little bit of interest

so make reference to the pstat table i published and check that you are in the zone - if you have the machine next to an open wind or other strong source of strong air movement it will have an additional cooling effect on the group

so once you have the pstat set about right do a visual check to see that you are getting at least some chocolate brown flecking in the crema - if not you are probably on the cool side - if its all dark chocolate brown crema you are too hot

don't over think it!

the L1 only asks that you observe broad principles - not nano measurements of precision

let us know how you get on

& finally, the pressure stat readings i refer to are maximum readings you get on the dial - forget all other values!

reiss

joe jeczen

Reiss, Dan,

I just got back home and left the L1 on when I was gone out for dinner, it actually comes up to 1.25bar. I suppose I just looked at it randomly and was going from memory before.

My shots taste really awesome and the flavors I've been getting since owning the L1 are unforgettable.

The room temp in my condo is pretty nice, it's my bachelor pad when I'm not at my girlfriend's house so I crank up the heat to 72F. Not sure what that is in Celsius, but it's pretty comfortable in here, no drafts, my place was built in the 90's.

In any case, I'm open to adjustment and am still trying to understand if that pstat would have that big of an impact on the overall temp for lighter roasts.

Cheers~