# Unclean roast produces bad results?



## uma_bica (Mar 28, 2012)

Hi,

Last week I've bough 250g of Blue Sumatra from the Algerian Coffee Shop (just wanted to try something new). I should stress that I'm quite a newbie when it comes to home brewing.

Anyway, I've noticed the beans had loads of impurities: seemed like beans skins or just little bits from whole beans. As if the beans hadn't been well clean prior to roasting. Anyway, I've tried all possible "settings" in my Zassenhaus - squeezed the screw as much as I could and still couldn't get anything decent. No crema was produced and the coffee started dripping after just 2/3 seconds of pre-infusion (I have a Pavoni lever machine).

So, my question is, are those impurities the most likely cause of the bad results I got? Or could it (also) be that the coffee was stale? Or even any other factors like my machine not being able to grind fine enough for those beans?

Unfortunately I didn't take any pic of the beans







.

I went back there and got some Formula Rossa - their most sold one -, and the beans looked so nice compared to the ones I've mentioned above... and guess what ... I managed to get quite a nice, close to 15s, extraction (still far from getting a great extraction, but with some nice persistent crema).

Cheers


----------



## MikeHag (Mar 13, 2011)

Difficult to say. Sumatrans can be quite variable in quality, and can have a bad reputation with some people. I believe they are often processed in combined cooperatives of micro-farms, so traceability and quality suffers as the less rigorous quality control in some Sumatran areas can indeed lead to defects and taste problems. They are also often dry-processed (natural) back in Sumatra, which can give them 'funky' flavours and leave more of the parchment on, which isn't itself a defect ... more of a characteristic. At least that's my understanding. There are good Sumatran beans out there, but maybe these just weren't.

I hope this does't put you completely off Sumatrans. Hands On Coffee has a great Sumatran Mandheling, which is a semi-washed Grade 1. Lots of body and chocolate. http://www.hands-on-coffee.co.uk/on-coffee/


----------



## Outlaw333 (Dec 13, 2011)

It is fairly common to find little bits of chaff in the bottom of a bag of beans and quite often when I grind for brewed coffee more so than espresso, I get little flecks of parchment in the grinds, this is just part in parcel and nothing to worry about. Without a picture it would be difficult to say whether yours is something unusual or not, it won't be from unclean roasting proceedure though as unless a roaster is spotless they hit a flash point and catch fire during roasting!


----------



## garydyke1 (Mar 9, 2011)

uma_bica said:


> Hi,
> 
> Last week I've bough 250g of Blue Sumatra from the Algerian Coffee Shop (just wanted to try something new). I should stress that I'm quite a newbie when it comes to home brewing.
> 
> ...


more likely to be problem-causing than some dried Mucilage or parchment.


----------



## xiuxiuejar (Jan 24, 2012)

I love Sumatra / Indonesia - they are some of my favourite coffees but, alas, as Mike Hag quite rightly says, they are notoriously varied in quality and there is little worse than a bad Sumatra / Indonesia. When they are good, they make wonderful acidic, full bodied, corpulent coffees but when they are bad they basically make dirty dish water. And they problem is that you never know until you try them. I particulary love Kalosi Toraja but have given up ever finding a decent one again!

Having said all that, you may have just been unlucky and got the chaff at the bottom of the bag. I doubt the coffee would be stale if it is a good roaster. However, it may have been overroasted which is another common problem for Sumatran beans. They like to be roasted but there is a very very fine line between a medium-dark roast they prefer and over roasted.

Also, once again echoing Mike Hag, don't be put off because Sumatra / Indonesians are, at their best, wonderfully complex, rich coffees.


----------



## uma_bica (Mar 28, 2012)

Cheers guys! I definitely won't be put off now that you mentioned that. I got a bit disappointed with those results so I went back to Formula Rossa - the first one I've bought - to see if I wasn't doing something stupid... The good thing is that, somehow, I managed to get better espressos from the Formula Rossa than initially. So, just by that I'm glad.

I'll definitely try another Sumatra!


----------



## uma_bica (Mar 28, 2012)

I'd like to add a few more words to this thread now that I upgraded from the Zassenhaus to an MC2. I haven't bought the same Sumatra beans again - but will soon -, but after comparing the (mediocre) results I was having with my Zassenhaus I took my Pavoni all the way across London to a friend's place to compare the grind made on his Rocky... got enlightened: it was the grinder!

I quite liked the hand grinding ritual in the morning and would like to try one of those old Zassenhaus to see if the problem is really the new ones...

Anyway, it's all about the grind(er)...


----------



## uma_bica (Mar 28, 2012)

Following up on this, I've bought again the same Blue Sumatra at lunch time and now going to do a "full" test with the MC2 and post here the results. Chances are that the coffee was just fine and the grind was far off.


----------

