Maier (1985)¹  compared the chemical composition of traditional and fast roasted coffees, using samples of similar roast colour, and found that the water-soluble extract (soluble solids) increased as the roasting time decreased.  The content of specific substances (such as saccharose) changed with the roasting, indicating that chemical compositions of traditional and fast roasted coffee are similar but not identical.  As expected, fine grind of coffee samples led to an increased amount of extract.  Interestingly the difference in the soluble yield between traditional and fast roasted coffee was dimished by fine grinding. This supports the thesis that fast roasted coffee shows increased brew strength due to structural but not chemical changes.

I hope to have some time this weekend to look at a few more things, I just wanted to keep the debate going.  There is some more info on bean swelling that I want to post up too.

1. Maier, H.G. (1985) Zur Zusammensetzung kurzzeitgerosteter Kaffees. Lebensmittelchem. Gerichtl. Chem., 39, 25-9

As always the paricipants there were way smarter than me and offered several interesting options. I dropped into the thread that this was part of my idea of a grand unified theory of espresso, and subsequently a few people mailed and pm’d me asking what on earth I was talking about and what density had to do with it.

Well, I should probably explain what I have been thinking. ²

When approaching a coffee and brewing it using an espresso machine you are often searching for an ‘ideal’ recipe for that coffee.  For many of us knowing as much about that coffee as possible often helps make intuitive judgements about things like dose and brew temp.  If I get my science wrong then please, please shoot me down. ³

One of the things that broke my head about roasting early on was the discovery that the longer/darker you roast the less potential solubles you have.  This may seem obvious to some but it always felt like the roasting process created many new flavours but one must distinguish between flavours and solubles.  This explains why instant coffee is roasting very fast and relatively light – they are interested in a percentage yield so the more solubles the better, regardless of taste.

Knowing this then made something I had experienced make apparent sense – darker roasts generally prefer higher doses, because you need more coffee to get more solubles to get a nice, thick and pleasant espresso.  But after a moments thought it didn’t make sense.  This would mean that you would get a thicker, heavier cup with a higher TDS measurement from lighter roasts but lighter roasts generally produced delicious but lighter bodied cups.  What nudged me towards density was how we approach very high grown coffees versus lower grown coffees.

Higher grown coffees (and let me make a broad sweeping generalisation here) have a much higher acidity than their lower grown brethren.  When brewed as espresso they can easily yield extremely acidic and unbalanced cups and, taking unbalanced and pronounced acidity as a sign of underextraction, I found that higher brewing temperatures helped to produce a more balanced cup.

What do lighter roasts and high grown coffees have in common:  higher densities.  Though there was more to extract (in theory) you had to work a lot harder to do it.  Therefore reducing the dose of a lighter roast/higher grown coffee gave you a higher ratio of water/energy to coffee to help extract a tasty cup.  (I often think of heat energy as some sort of currency, with which you can buy solubles.  The more heat, the more you extract/purchase.)

This is all well and good for convenient examples – high grown, light roasts versus low grown darker roasts.  Give me a clean prepped coffee from relatively low altitudes in Brasil, roast it into 2nd and I will likely be dosing quite high and not brewing too hot.  I’ll certainly be dosing it very different from how I might brew a lot of Aricha as a straight shot.

But what about a light roast of a low grown coffee, or a dark roast of something grown super high up?  This is what lead me to wanting to find a way to measure and compare the densities of coffee beans to see if there was correlation between the density of the end product and an ideal brew temperture of particularly effective dose.

So – if I have had such a good idea why don’t I do all the research and then publish it all at the end of it and try and stamp it “Hoffmann’s theory” or something equally absurd? (Apart from the fact that it is absurd).  Because I want to generate a little discussion about this.  I want people to weigh in and tell me I am being stupid/simplistic and to suggest better ways to test these ideas.  I want to understand espresso better so I can make better tasting drinks and translate coffee’s journey more transparently in the cup. ⁴

I really hope people will offer their opinions on this idea, shoot it down or take it and run with it.  I am going to start doing some basic testing and see what happens.  Lots of little experiments appeal. ⁵

1. There really is no better place on the web for these kinds of questions!
2. Some of this is based on personal preference, some on what seems to be fairly well agreed upon within the community of people who worry a lot about their espresso.
3. There is another post in the works about the value of being wrong and discussing it afterwards – yes, I have a big wrongness to confess to…..
4. I know this is a wordy post and all, and I would have put some nice photos in but my camera is dead
5. For example – if I roast two coffees til their densities match – will they grind the same, and at the same dose will they extract the same?  Would they be ideal, therefore, to blend together to get the most out of each of them.  This probably shouldn’t be a footnote, but it is.  So there.

No one in the coffee industry really likes decaf.  We excuse its taste, we get annoyed at how fast it stales, we treat it as a second rate coffee experience.  I was in that camp too for a while.  Coffee no good?  Well, it is decaf…..

Stumptown ruined that for me.  During our West Coast trip in 2007 we were hanging out with the former roaster Joel, chatting about the UG15 he was roasting on (we were just buying ours at the time), and having a great time.  Joel disappeared to the bar and came back with a shot for Anette and one for me.  It was very tasty, sweet, full bodied and clean.  It definitely wasn’t Hairbender.  I was nearly floored when he told me it was their decaf.  That caused a problem: I no longer had an excuse.

Anette does a great job roasting decaf, and I think that experience is one of the many reasons high.  As our memories improve and elevate that particular espresso it means our own bar will constantly be lifting.

I think we make a grave mistake alienating decaf drinks with tonnes of pre-ground, nasty coffee brewed without much care.  These are people who are buying coffee because they like the taste.  We are supposed to love these people – they aren’t the ones suffering through awful espressos or instant coffee just to get their caffeine fix.  And yet they are the people least catered to in the industry.  A shame.

I am not going to go through who won what (it is there on the website still) but there are a couple of things about this auction process, about the success of this farm, that I want to write a little about and get some feedback on from the community.

First of all I was quite surprised that the Petersons decided to auction off so many small individual lots. The high prices achieved in the past were a function (in my mind) of both quality and scarcity. I don’t debate the mesmerising cup this coffee is capable of producing, but I don’t think that it would have reached $130/lb last year if there had been 10 times the volume available. Granted, the small individually processed batches have drive the price up on the top lots to similar heights but this then leaves the issue of how to communicate the difference between Stumptown and Sweet Maria’s $105.25 lot and a $6 lot. What key areas would the consumer respond to and be willing to massively increase their spend for?

The variation in price also implies a variation in quality. This is not a criticism of the farm – no farmer in the world is going to claim they produce nothing but exceptional coffee. I do worry, however, that there is potential to damage the brand. (and I have no doubt that it is a brand now) I have seen more extreme examples of this in other super-farms such as Daterra. Daterra is a cutting edge farm, capable of producing stellar coffee, and the research they are involved in is invaluable. I know they did a great deal of work on tracing aroma in the cup back to the crop with Illy and I hope eventually some of that research will see the light of day. What surprises me is that they have not distinguished very strongly between their best lots (like the reserve) and then other lots which don’t taste as good. I have seen several roasters proudly claiming the Daterra component of their blend without specifying which one it was and the coffee not tasting great. I thought the idea of the Esmeralda Especial worked well, but was still being muddied by some people so if anything I would have thought they would have distinguished lots even more aggressively.

I feel very strongly that for us to really move forward in speciality coffee we must consistently deliver on our promises to the consumer. Asking them to pay a high price for a cup promises that it will be worth it, and making proud boasts about the coffees we use promises that they will taste something that will be starkly different, discoverable and satisfying. Will every single roast of the Esmeralda be great this year from all the different companies? Does a new, but interested consumer, tasting an average cup of Esmeralda leave them very confused about the prices of the higher lots? Do we risk looking exclusive rather than inclusive to those teetering on the edge of becoming interested and excited about great coffee?

My other thought on the success of the farm has been the double edged sword of the visibility of the Geisha varietal used. I travelled a little bit in Costa Rica last year and every farm I visited had at least a little Geisha planted. Some were more cautious than others in the space they were giving over to the gamble. In three or four years will we see a sudden flood of Geisha on the market (which will immediately drop its desirability) and will it be any good. A while ago I dug through my coffee text books to see if I could find any references to the varietal. I found very little except for a small study carried out abotu 40 years ago in Costa Rica comparing the success of various varietals of which Geisha was won. It lost out primarily because of its lack of yield – less of a problem if you have quality and scarcity on your side, but with lots of people suddenly producing lower yields from their farms scarcity becomes void. No notes are made in the study about increased cup quality, but that study could still easily be dismissed as techniques have moved on and you could also argue that Costa Rica’s quest for yield held it back as an origin producing distinct and amazing coffees until the more recent micro-mill revolution that we are seeing signs of. (if people want me to dig up the study I can do)

On this subject I am very happy to concede I might be wrong. I haven’t spent enough time at origin to feel completely confidant in the above statements, and if Peter or Geoff or anyone else who has spent a lot of time at origin are reading and want to correct me I would be very grateful. I really just want to learn more, and hope that we aren’t all debated-out on this issue which covers just about all of the coffee industry.

However I think the photoset from the Probat Museum will be of interest to quite a lot of people. I’ve tried to add a little info to the pictures – size of batch, date of manufacture etc…

Probat Museum Photoset

I have the museum guide so if anyone has any questions I will try and answer them. If you

Probat Museum Roasters

I will post more once I’ve sorted the photos – the museum alone is worth the trip to Emmerich. I had my video camera with me and took a few things. It is my first effort with iMovie, and probably doesn’t make much sense – it is just a bit of fun really. I’ve uploaded a version to YouTube if you want a quicker loading version (I don’t like the encoding youtube does much though)

[flv:/video/probat.flv 320 240]

So I pulled a few shots this afternoon and I now feel like I can properly focus over the presentation.  I have made almost all the decisions about the coffee – a few profile things to sort out – and I am pretty set on my sig drink now (yes, I should have decided something 2 months ago – remember kids: organise, it really helps.)

 In other news I received some coffee from Germany,courtesy of Wolfredo who looked kindly upon my lack of coffee.  This is the first time I have received coffee packaged like this.  I was impressed!  I look forward to trying it tomorrow.

Those of you I encountered on my roadtrip, and Stephen especially, will be sick of this particular rant/”philosophy”.  I will start with food, because food is wonderful and I suppose that it is the best metaphor (is it possible to write about coffee without endless metaphors?).

I think most of the time we eat because we are hungry but we aspire to eat something tasty.  Be it tacos (look, I am obsessed – leave it), a great steak or a beautifully cooked lasagna, this is undeniably great food but entirely different from a plate of food Wylie Dufresne may serve you, or something Adria may conjure.  They, of course, are not even vaguely alone in plating up dishes of food that are to be eaten and enjoyed by the head more than the heart.  Food where the pairings of ingredients are spot on, clever and interesting and it undoubtedly a pleasure to eat but isn’t food you crave.

Most customers approach coffee from a very functional point of view.  It is needed, for chemical comfort or just as part of routine and of course (you hope) for pleasure.  However, a lot of the time it feels like we are looking for the cups that are intensely unusual, complex and of course interesting.  Coffees from Idido, for example, are incredible – full of intense fruit flavours and treading the fine line of wild beautifully.  They are coffees that taste nothing like coffee.  I love them for what they offer as well as what they suggest coffee is capable of.  However, first thing in the morning as I stumble down the stairs, or when I duck into a cafe out from the cold I want coffee to do something else for me – I just want it to be tasty.  It is cups of coffee like this that will become benchmarks of our nostalgia.

I love cupping, I love the ritual and I love pushing myself in an area I see a huge room for improvement.  However I am often in fear that certain coffees are glossed over because they aren’t blockbusters.  Yet at home I am yearning more and more for tasty.  Which is odd, as I had been (not so long ago) hell bent on a path of discovery and a search for the blockbuster type coffees.  This morning I brewed a Chemex of coffee (better than any chemex as I had been grinding too fine – thank you to Kyle G for fixing that) and it was so very tasty.  I don’t think it was as good as the coffee could be – I know the co-op well and the coffee is capable of extra-ordinary fruit – this cup was just balanced and rounded and perhaps lacking in complexity but still immensely enjoyable to sip at as I wrote a few e-mails and caught up on the feeds.  I didn’t want to have to think about it, I just wanted good coffee.  I do worry that coffees like this will get left behind in our exploration of coffee’s boundaries.

It wasn’t until I broke one of the shiny ones open that I worked out what was going on.  Inside the dark, sticky beans the colour wasn’t nearly as dark and in fact was pretty light.  I stuck one in my mouth and the weird sticky, sweet outer coating (the person I was with suggested sugar puffs as a description and he was spot on) pretty much confirmed that these were the result of the weird and rarely seen (in the uk anyways) practise of throwing sugar in the with the beans to help disguise qualities of the coffee.  Back when I was just getting into coffee chemistry I managed to get hold of my first scientific paper and it was about this style of roasting.  Sadly (sort of) I didn’t get to taste them.  I sort of want to know more – do you need special equipment for this?  How much sugar do you add?  Do you spray on sugar water?  Can it ever possibly actually taste nice?  Anyone ever had a go?

Last year the show was crazily busy for me.  Apart from an amusing and brief appearance on BBC breakfast tv on one the first day that meant people at the show kept asking if they had seen me somewhere before without being able to remember where, I strongly remember plowing through a lot of coffee (the remnants of my UKBC blend of that year) and serving the majority of it as espresso which seemed a pretty good thing at the time.

I am spending a bit of time today working on my presentations for the show.  What is interesting is that this is a tradeshow that has realised that the internet has pretty much killed the traditional tradeshow (you can see most products in almost infinite detail online, and get most prices too) and has turned to education to add value.

Aside from traditional seminars – I am doing one about barista competitions – they have gotten involved with the SCAE UK Chapter to run an impressive selection of workshops in 4 separate classrooms.   Each workshop has a different theme – Espresso, Filter Brewing/Cupping, New Start Up, Advanced skills.  I like that they are trying to get away from espresso as a central theme.  It is good to see Clover will  be there, as well as shop roasting workshops and good solid basics like how to layout a bar so it actually works (all too rare in the real world sadly).  I think Se’s presentation on how to improve your UKBC performance will be well attended as well.

I openly admit I am involved in one session – the advanced barista skills one – but if people get behind this I think it is really going to be excellent and set a very high standard for what the SCAE can offer.  All the classes and the instructors are listed on the website here.   We need to see education spread further in the UK, we need people to see the value in it – though I don’t think anyone reading this will seriously question that – and I think this event is a really good step in that direction.  And at £20 a session (if you buy 5) it is absurdly cheap (I think they’ve sold a fair few already).

The last time I did an advanced barista workshop was in Ireland (For the SCAE chapter there) I think I misjudged the audience a little bit.  I maybe went too much science not enough fun.  I hope not to make the same mistake twice!

I guess I am posting about this because I want to spread the word about an event with strong training and education (that has been my role for the last 2 and a half years)  that I see as being really positive and would dearly love to see it be the success it deserves.  That and (if I am honest) I really hope people come to my workshop!