John, a constant source of good ideas, came up with a plan. We could take the front door of the roaster off, replace it with perspex, throw some coffee in and see where the bean mass was most easily measured.

I have to say that being able to do stuff like this, working with people excited to geek out and experiment, and have fun while doing it makes me very happy!

We had some coffee that was going to be trashed as there had been a gas pressure issue early on in the roast so we’d dumped it. (In case you are wondering why the coffee in the roaster is such a funny colour!) We learned a lot from our little experiment – and it was fun too!

I threw together a few clips from video I shot as we were doing it because I thought other people might find it interesting. Not included in the short are several of the trial and error attempts!

The eagle-eyed amongst you will notice that because the perspex didn’t fit super tight there was some massing of the beans where the movement was clearly restricted compared to how the would be moving when the roaster was in normal operation.

(Music: “Do the Astral Plane” by Flying Lotus)

I look forward to more experiments!

I don’t really want to write this as a response to the articles Giorgio Milos has been writing, though they’ve probably helped crystalize some thoughts. We, as an industry, are continually struggling to deal with the impact and importance of Italian espresso traditions.

What has been on my mind has been the idea that tradition is something immutable, something to be preserved and studied.  This just isn’t true – tradition is little more than persistant ideas, roughly copied using the human mind.  Their memetic nature means that a tradition will adapt and change in order to be valuable and be passed on.  What distinguishes tradition from historical cultural artifact is relevance to the current culture.  What is traditional is not correct, nor perfect, it is merely useful enough to keep alive as an idea.

What does this rather wordy paragraph have to do with coffee?  Espresso is Italy in 1950 would be further away from espresso in Italy in 2010 than espresso in the USA in 2010.  I hope, and strongly suspect, that espresso in Italy today will be abhorrent to an Italian in 2060.  Tradition must evolve.

Tradition is not an excuse to stop exploration and progression.  Deviation and experimentation away from tradition absolutely must happen in order to discover new and useful things that will become the traditions we will pass down to future generations.

This doesn’t mean we should ignore the ideas that have survived best until now – if we can understand the 7g dose then we stand a better chance of avoiding mistakes that have already been made, of learning from past experiments.  My understanding of this dose, current machinery and extraction have all changed dramatically in the last year but if I’d either completely ignored the 7g or followed it slavishly I wouldn’t have had that learning experience.

Understanding the influence of economic factors on the birth of traditional espresso blends (coupled with regulation of drinks prices) explains more about the presence of robusta, or unwashed coffees from Brazil, than taste does.  This isn’t to say that people don’t enjoy blends like these – but you can’t help but end up at the conclusion that taste preferences weren’t the driving factor they are sometimes made out to be.  This means that if taste is your driving force then perhaps a different approach would be preferable.

I think the thing that most annoys me about the articles, and it annoys me about a great deal of culture, is the idea that diversity is not to be celebrated and encouraged.  I’d hate to see Italian espresso in its current form disappear completely, but I’d hate to see it become a ubiquitous, monotonous method more.

More info here.

So I grabbed 7 of them and took them in to work.  We’d talked about sourcing tea cups for Penny University for certain coffees (like the Yirgacheffe) where we thought a cup could really enhance it.

Having tried brewed coffee (and enjoyed it very much) I couldn’t help but want to try espresso…

It was really, really good.  Embarrassingly good – you couldn’t help but feel a little self conscious drinking from the cups – but true to John’s word – the lip disappeared.

A few thoughts in my head to finish – because this is really just a fun little post:

1 – We really need to explore the vessels we serve coffee in.  I like owning diner mugs a lot more than I like drinking out of them.  I know it has been brought up before, but we still haven’t really done much

2 – As Tim would point out:  Is there any way you could get something like this into service without coming across as being incredibly pretentious?

3 – I now want to buy lots of different tea cups.  I worry this could get expensive.  If anyone has any recommendations I’d be interested!

4 – The disappearing lip thing is one of the reasons I really hate hot espresso cups.  I don’t want to notice the cup, and a scorching hot cup is really quite a distraction.  I also really enjoy espresso when I barely notice its temperature – when it is close enough to body temperature that all you thinking about is texture and flavour.  This may also seem a little pretentious but I’ll survive…

I’m sure it is no leap to see where I am going with this, and also clear that I am not claiming this as original thinking!

I began to wonder if pressurised brewing could be applicable to more than espresso. Cold brewing (not icing hot coffee to dilute, but brewing with ambient/cool/cold water) is often a little disappointing. While you can get a balanced and tasty brew you sometimes miss out on some of the interesting aromatics and flavours, as well as the acidity, of some coffees – due to a lack of heat/energy to extract them.

Could pressure add the necessary energy – perhaps even allow rapid cold brewing?  I loaded a syphon with 15g of coffee and 250ml of water, pressurised it, shook vigorously and then waited a minute and released the pressure.  I strained it through a V60 and tasted it.  Disgusting, barely any extraction.

“More time….” I thought – so I set up a longer brew.  The results were very tasty.  I needed a control sample, so last night I experimented again.

The two brewers

I would use the same amount of coffee, water and use the same brew time.  One brew would be in a french press, left to steep.  The other would be pressurised.

Matching doses within 0.1g

For the coffee I used a test batch of the washed lot from Finca Killimanjaro, from Aida in El Salvador.  We’d already cupped it and I knew it to be juicy, tasty and not an obvious coffee to (traditionally) cold brew.

There is a lot less bloom with cold water.

I steeped them for 12 hours – the french press lidded and two charges into the cream whipper.  (If anyone knows how to calculate how much pressure the liquid was under I’d be very grateful!)

This morning I strained the two coffees in preparation for serving to the rest of the team at the roastery.  The french press brew looked fairly normal:

Straining the press pot

Straining the pressurised liquid was very different.  Overnight the gas had gone into solution and releasing the pressure meant that it began to bubble and fizz out (this is important – more on this later!).  It doesn’t look very appealing to pour a mass of fizzing coffee slurry into a V60!

Fizzing coffee slurry

The coffee also looks a little odd initially as I think it was still giving up a little of the dissolved gas.  Very quickly it just looked like paper filter coffee again.

Pressurised cold brew coffee

I served the two coffees blind to everyone, though it was clear there was an obvious winner.  Everyone picked the pressurised brew as being more delicious.  I checked the extractions with the Mojo and the preference made sense.  The ambient pressure cold brew struck out at a lowly 14% extraction.  The pressurised brew (with identical time, brew temp and grind size) came out at 18%.  This was a pretty significant change to the brewing process.

Now – I know what you are thinking:  Is the pressure speeding up the extraction.  My initial thoughts are:  probably not.

I think that the aggressive fizzing upon depressurisation and during the pouring process was effectively and noticeably agitating the coffee grounds increasing the extraction.

What I’d like to try next is to compare an ambient cold brew that gets up to 18-19% extraction (into the zone of deliciousness) to a pressurised brew of equal extraction.  I’ll probably need to agitate the coffee in the ambient brew to get it to do that without introducing a new variable between them of brew time.  This should also give a slightly clearer impression of the role of pressure outside of its agitating effect.

The coffee:  pretty damned tasty – and some nice acidity/juiciness in the cup which makes me hopeful.  We did it with one of the Kenyas we have (the Tegu AA lot) and it was seriously delicious.  If any of you have a cream whipper and some spare time and want to experiment too I’d love to hear about it.  Thoughts, suggestions and gentle berating for silly experiments always welcome in the comments!

His latest post is great.

It raises, to me, a few rather uncomfortable thoughts and ideas so I thought I’d share them in order to make them less terrifying.

What we should take, first and foremost, from the food world is the accessibility of quality. This is where coffee falls down a little.

You could argue that first we have to make the consumer aware of quality within coffee, we have to change their idea about how good, how exciting, how surprisingly delicious it can be. You could argue that, quite rightly, people don’t have much in the way of expectations for coffee the way they might do for steak. ¹

You’d be wrong to argue, I think, that this is the consumers fault. They don’t lack the palate, they don’t lack the interest. They suffer a lack of availability, no doubt. Even if you like good coffee it is staggeringly hard to get. Do the maths – take the population of your local metro area and divide it by the number of great coffee places. In some cities great coffee places become one in a million.

But there are great coffee places. More and more open, every month, every year. The question is: are we making this coffee sufficiently accessible? I don’t just mean available, but more approachable.

99% of people you meet have probably had a less than ideal experience and past history with coffee. Marketing has always been ahead of what was produced, promising more than it delivered. People have been very disappointed, routinely, for years by the coffee they’ve bought. It makes them feel duped and angry (and more likely to leave comments on coffee articles online…)

There are places you can go to enjoy a meal that serve great food. Delicious food. They do it as if it is the most natural thing in the world, not special, not unusual, not fashionable. They charge appropriately and trust that you – the diner – will notice and appreciate the quality of what they do. No one thinks you’re a little strange because you spend a little more, travel a little further, or queue a little longer for a great meal.

Very few places serve great coffee in a matter of fact, friendly, casual way. We like to talk it up. We like to shout about it.

Are we shouting, posturing, proclaiming and promising because we worry that otherwise the customers wouldn’t notice that it’s better? Do we not trust them? Surely if it isn’t sufficiently different, better and more enjoyable that anyone tasting it would easily notice the difference – then are we doing a good enough job?

It is these last thoughts that are the most uncomfortable, the most worrying. With Penny University (there is a whole other blog post on this coming) we tried to aim high, hoping that people would be up for trying something new, something different. We still underestimated our customers, which is both incredibly exciting and a bit embarrassing.

If you opened a little cafe but made no promises, did no marketing, and served great coffee (truly great coffee) and gave no clue about its specialness other than the fact that you charged an appropriate price – would people notice? Would it be a success? If you left it to just the taste of the coffee to do the convincing – would people be convinced?

I think so. I certainly hope so. Do we, as an industry, genuinely believe so?

1. Don’t ask me why I picked steak – except that steak something that a lot of people can get very excited about. For good reason….

I hope we can get to a place where we can discuss profiling, roast development, densities and the like with a view to understanding what we do better and to reduce the time we put into trial and error profiling. Undoubtedly lots of great roasters aren’t just heating and hoping – they are applying a lot of what they’ve gained from previous experience and other knowledge.

Below is an email exchange between Deaton Pigot, Chris Kornman (both roaster with Intelligentsia) and myself. It had come about after a comment I’d made on someone else’s blog about there being no sugars in roasted coffee.

As becomes evident in the exchange – there really is a need to better define what we are talking about when we use the term sugars.

I wish I could say that all my emails are like this, that every day is an in depth discussion of theory combined with our experiences.

Unfortunately this conversation didn’t get any further – work has a terrible way of getting in the way of things like this. I can only speak for myself here, but feel free to pick apart things I’ve gotten wrong or misunderstood. If people would like to contribute anything – please post in the comments.

From: Chris Kornman [mailto:xxx@xxx.com]
Sent: Thursday, January 21, 2010 11:43 AM
To: Deaton Pigot
Cc: xxx@xxx.com
Subject: Re: This is interesting

So we got interested in this “no sugars” claim by JH below, and Josh &
I did some digging.

Sucrose (aka white table sugar, chemical formula C12H22O11) has a
melting point at around 370F (so sucrose, if present in coffee, would
caramelize at or before 1st Crack.) It breaks down into water vapor
(H20) and carbon dioxide (C02).

According to our colleagues Henry Schwartzberg (Professor Emeritus,
University of Massachusetts) and Joachim Eichner (Praxis International
Inc), during the roast, Polysaccharide (Starch chains containing sugar
polymers) Hydrolysis (water breakdown that splits polymers) in the
cell walls of roasting coffee results in the creation of sugars and
oligosaccharides (simple sugar chains). Also, sugars break down to
form Aliphatic (fatty) acids.

So roasting both creates and decays sugars.

Rapid decay begins later in the roast, (11min according to HS & JE),
so likely during or after first crack. The decay of sugars also
produces alcohols & furfural (“…an aromatic aldehyde… Its chemical
formula is C5H4O2. In its pure state, it is a colorless oily liquid
with the odor of almonds, but upon exposure to air it quickly becomes
yellow” – Wiki).

It seems unlikely that full degradation would take place before the
end of 2nd crack, however.

So, yes, there are sugars in roasted coffee.

-ck

On 21 Jan 2010, at 20:11, Deaton Pigot wrote:

Hey James,

I am emailing you because of your comment on the Double shot blog about
sugars left in coffee after roasting. I am sure all of us would love to hear
your thoughts on our mail chain. That is of course if you have the time to
answer.

Hope you are well!

Kind regards

Deaton

Chris and Josh that is a great read! Out here we (or at least I) have bought
into the Staub theory of developing sucrose. IE Polysaccharide split into
monosaccharide, creating a foundation of sucrose that would essentially be
dug into the later stages of the roast.

I went into it in some detail here

http://deaton.wordpress.com/2009/07/12/balancing-act-sweetness/

Plus some of it here as well.

http://deaton.wordpress.com/2009/05/07/how-sweet-is-your-cup/

I know that in James comment he stated;

“Nothing to do with sugars – of which there are none left in roasted coffee,
certainly not simple sugars which react away through maillard, caramlisation
and strecker degradation reactions.”

So it leaves me wondering what sugars he believes are left in the bean after
roasting, as we all know we do perceive varying levels of sweetness.

From: James Hoffmann [mailto:xxx@xxxx.com]
Sent: Thursday, January 21, 2010 2:13 PM
To: Deaton Pigot
Subject: Re: This is interesting

Hey Deaton,

I could well be wrong – it’s usually the case.

I will dig out the reading I’d done on this – by sugars I meant simple sugars, rather than long chain complex carbohydrates.
No doubt there is sweetness, but more things than simple sugars create the sensation of sweetness on our tongue. Sweetness reception, like bitterness reception, is complex and only reasonably understood.
I find the sweetness of coffee to be unlike the sweetness of simple sugars. I’ve had very sweet shots, for example, but not ones I would describe as sugary.

Give me a day and I will either get pwned or add something interesting.

Kind regards,
James Hoffmann

From: James Hoffmann [mailto:xxx@xxx.com]
Sent: Thursday, January 21, 2010 3:39 PM
To: Deaton Pigot
Subject: Re: This is interesting

Hi Deaton,

I think the tricky one here is going to be pinning down a useful definition of sugars.
Once polysaccharide chains get longer they are perceived as being less and less sweet. In the past i used an 18-chain multidextrose to make non-sweet syrups.

The simple sugars, as would be perceived as having a strong sweetness, are very reactive during roasting – through maillard, strecker and caramelisation. Certainly there are some longer chain sugars in the mix.
Most of the research has been done on lower quality coffees, which will always leave us a little in the dark I guess.

Having dug through a couple of textbooks I am up to the following to support my initial statement on the lack of sugar in roasted coffee. If you want the full paper titles referenced then let me know and I will dig them out.
When talking about sugars I am talking about low molecular weight carbohydrates (R.J. Clarke’s definition). On a side note – related to the original post – it seems Petracco et al (1999) isolated a polysaccharide that actually increased foam stability. I digress….

Trugo & Macrae (1985) did a study that showed 97% sucrose loss in light roasted coffee, creeping up to 99% in a dark roast. Hughes and Thorpe (1987) came up with 0.24% and 0.34% sucrose in roasted coffees. Sucrose can hydrolise into glucose and fructose but both degrade thermally more readily than sucrose.
Noyes and Chu (1993) found 0.1% sugars in 21 roasted Brazilian coffees – though most of this (0.08%) was sucrose.

My reading implies that most of the polysaccharides in coffee are extremely stable through the roasting process – according to Bradbury and Halliday (1990), and hydrolysis would have to happen at lower temperatures when there was still water available. I couldn’t find data on water activity and roasting temperatures – to understand when hydrolysis would stop. Will keep looking.

I guess what I would look to argue is the breakdown of the polysaccharides – which ones are breaking down, into what size chains? Do these chains have detectable sweetness? What molecular weight do we use to decide a cut of point for sugars?

Food for thought…..

Kind regards,
James Hoffmann

Related Reading

For reference this older post on the Maillard Reaction, Strecker Degradation and Caramelisation may be of interest.

We’ve all at some point cupped a coffee and wondered why on earth the roaster has taken to such a high end temperature – surely, when they cup it, they taste that the flavour is utterly dominated by roast notes. “Why”, you think “would they do that?!”

Usually we can dismiss the very dark roasted stuff under the idea of “They are just trying to cover up the flaws in their low quality coffee by roasting so dark that any negative flavour/defect is turned into charcoal.”  More recently though I’ve come to think that given a certain period of time you pretty much stop noticing a group of flavours, resultant from roast rather than being an intrinsic flavour to the bean.  These flavours may be the result of very light roasting, through to very dark roasting.

I remember reading a comment online from someone who worked at a roastery in the US remarking that they roasted in a way that resulted in absolutely no bitterness.  I can see their point – I often taste coffees where I don’t really perceive bitterness unless I think about it.  Yet all coffee is to some extent bitter – caffeine is a bitter tasting compound, as are many other resulting from maillard reactions etc.  The coffee simply fell below the level of bitterness that was habitual and therefore was ignored.  If you’re reading this then you’ve probably recently had coffee where you didn’t notice any bitterness at all.

We talk about how complex coffee is – from an aromatic and chemical point of view.  These 800-1000 near mythical flavours that have been idenitified (across the entire range of coffee I should add, rather than in a single cup) are brought out as a statistic to brag to the wine people about.

Chances are that we can’t possible perceive everything there is to perceive, so we look for what is interesting – we look for what is new.  My thought is that if you roast to a certain depth/degree/temperature regularly then there will often be a very similar group of flavours.  This will come to be ignored.  What I am thinking is that that group of flavours is very much learned, and continues to be malleable – depending on what you regularly drink and cup.

For me there are bags of coffee that we taste over the course of a year that have noticeable roast notes to me, and there are also many that have a certain grassiness to me.¹

With the super light roasts I think that some flavours become habitual, just like with darker roasts. I am not sure at what point one flips. I don’t know where “the consumer” has its preference, if indeed it does at all.

I should probably add a couple of links here. Peter Giuliano’s comment from an earlier post² and a blog post that Chris Tacy posted earlier covering similar ground in a much more concise fashion.

1. For want of a better word!  I should probably state now that the whole development in roasting thing is something for another blog post, probably one where I ask a lot of questions….
2. every time I link to a comment of Peter’s – and it is pretty often – I think he really ought to have a blog….

I’m still trying to work out cold brewing (i.e. brewing using cold water), and since I read Peter Giuliano talking about the Japanese iced coffee method that has been a method of choice.

The idea with this is to brew double strength coffee straight onto ice.  As the ice melts it chills and dilutes the coffee back to more normal strengths.

Often this is done with pourover or filter brewers.  The problem I had with this is that as you double the amount of coffee to your amount of water then it is going to be harder to properly extract it as you have less brewing liquid.  You can certainly grind finer but I found the window of tasty a bit too narrow.

So recently I’ve been starting with a french press brew.  I like the french press for this because it isn’t as sensitive to dose because it is an infusion rather than a percolation.  You have a better chance of hitting a 19% extraction (in my very limited experience) with less brew water available, when working at very high ratios (120g/l).

However, I don’t really like sludge in my iced coffee.  So I’ve chosen to filter it before it hits the ice.  So for now here is the recipe I used today to make coffee for all of us in a very hot roastery:

- 80g of coffee ground coarsely. (But not too coarsely)

- Add 660g of hot water (around 92-93C is good)  I’d recommend preheating the brewer as normal.

- A quick stir then a 4 minute steep.  You could steep for longer if your grind is coarser but the heat loss starts to bother me.

- At 4 minutes stir the crust on top, then scoop off the remaining foam.  It may seem pointless to go through this if the brew is going to be filtered anyway – but you want the least possible fines to block the cloth and let that part be as quick as possible.

- Plunge and leave for a moment.  Again – fines settle and are less likely to clog up the cloth.

- Find a large vessel, and add 660g of ice.

- Find a clean cloth, like those used in woodneck drip pots.

- Pour the press pot through the cloth directly onto the ice.

- Clean the cloth.  Clean the press pot.  Enjoy the coffee.

You could use a paper filter to clean up the brew – a V60 or Chemex filter maybe.  I love cloth though – I love a cloth pourover already.  I love the enhanced mouthfeel and intensity – had a lovely, juicy sweet cup today that I really enjoyed.

I quite fancy playing with the aeropress next, which I haven’t really done with cold/iced coffee.

Thoughts?

The Other Black Stuff – At odds with unevenness

We should (as suggested on twitter) try to convince David to join the coffee world, because if someone outside of coffee can teach us this much and share this much then think what would be possible if this were his day job!