The State of Espresso in 2015

These are the results of the survey I conducted over the last two weeks. I had a great response to the survey – around 1,500 replies. I needed to clean up a little bit of the data (which meant discarding quite a lot of weird responses), but there was still a lot to work with.

I hoped that the data would give some insight into global, as well as local trends. I was also curious to know if there was much correlation between home consumers and professionals, in their tastes and styles.

Continue reading “The State of Espresso in 2015”

The Coffee Professional Beginners Guide

If you’ve just started working in coffee, chances are you’ve worked out that coffee is:

  1. Really, really interesting
  2. Huge
  3. Complex

As such you’ve turned to the internet to try and do some research. However, what is online is a rich mixture of information, without much hierarchy and often without a good place to start.

Here is a beginners guide to coffee reading and learning for an interested coffee professional.1 It is divided into three parts, based on how much money you have available to spend on learning more about coffee.

I will update this list whenever it seems appropriate to do so, and mark items as new. Continue reading “The Coffee Professional Beginners Guide”

  1. I might do one aimed more for the home consumer in the near future  ↩︎

An Analysis of Nespresso – Part I

This is the first in a little series of posts looking at how and why Nespresso works the way that it does. There’s a few things I think when it comes to Nespresso:

1). We continue to underestimate their success, and their ability to leverage technology to overcome hurdles of quality.

2). Speciality coffee roasters share more customers with Nespresso than they’d like to believe.

3). There’s a lot of speculation about the technology they use. Lots of it is clearly proprietary, so I wanted to dive into it a little bit more to try and understand what is happening.

Continue reading “An Analysis of Nespresso – Part I”

Reducing machine dirt buildup

Most things in coffee get a little easier the more you do them. Dosing consistently, understanding grind adjustment, understanding the taste of an espresso extraction, tamping simply and properly, the list goes on…

One thing that doesn’t get much easier is dealing with the build up of unpleasant flavours in an espresso machine. There are no shortcuts, you just have to deal with it regularly and to be honest it annoys me a lot. That taste is so obvious, so distracting, so unpleasant, that it ruins a lot of otherwise well made espresso for me.

I was thinking about the build up of dirt inside the group head caused by the release of pressure after you stop a shot. To better explain we have the following photo:


Photo courtesy of Dan Kehn of Home Barista

In a La Marzocco like this the route the water takes is a little confusing. It goes out of the far side of the neck of the group, through a flowmeter, back underneath the group head to a valve. When this valve is closed no water can leave the boiler, and when it opens water is pushed through and heads back inside the group head into that little tube you can see and towards the group head, until it drops down into the screw and showerscreen and over the coffee. 1 Other machines have a similar tube, of varying lengths, that run between the valve and dispersion mechanism above the coffee. (Not all LM’s have this long of a pathway outside the group – machines that don’t have flow meters and more modern models have eliminated this pretty much.)

Dirt builds up here because that last tube is a two way street. At the end of the shot the pressure shoots back up the tube until it gets to the stop valve. This prevents anything from getting back into your boiler, and this valve is a three way valve allow this pressure to exit through a drain tube, usually ending up in the drainbox under the drip tray – though some deposit straight into the drip tray in the E61 style.

The only machines that don’t have this problem are lever machines. Lever machines only release the pressure when the spring has finished expanding. This is why you can’t interrupt a lever machine shot without making a mess. (I believe the technical term is ‘portafilter sneeze’)

This tube is very hot. Any liquid in this tube will likely evaporate and leave behind whatever it had dissolved. At the end of the shot this can mean dissolved coffee gets dragged into this tube where it will quickly deposit and start to taste unpleasant. Some of that unpleasantness will be picked up when you next pull a shot and fresh water is heading down the tube towards coffee. The same unpleasantness builds up pretty quickly underneath the basket of a portafilter, and we know from sticking our noses in there how bad that would taste. 2

I was wondering if getting into the habit of flushing immediately after pulling a shot would dramatically reduce the build up of dirt in that particular area. As a flush builds up no pressure it would mean that water would only travel one way out of the group, and hopefully drag with it any coffee before it had the chance to dry out and deposit.

Some people would argue that you should leave the puck in for temperature stability. Even the WBC references this idea by no longer looking inside the portafilters at start up as you can leave pucks in as you wish. I don’t think temperature stability is a concern, but I do think dirt is. I’d rather lose a little temp at the start of the shot than have to deal with the residue of a puck sat in a machine for 10 minutes. I’m not sure I’ve ever seen any proof that having a puck in promotes thermal stability, and if it is out there then a link in the comments would be great!

Also – would using a rampdown in pump pressure tofinish the shot have a similar effect, as there would be little to no pressure to release back into the group?

  1. If none of this makes any sense then leave a comment and I will try and find a better way to explain.  ↩︎
  2. This build up is why I would use Cafiza on a domestic espresso machine every day, even if I had just pulled one shot.  ↩︎

A love/hate relationship with espresso

It goes without saying that trends and fashions are cyclical. What is in one day is out the next, only to be back in fashion once embracing it seems sufficiently different to what everyone else is doing. Such is brewed coffee vs espresso.  (I should probably warn you now that this is going to be a fairly long post…)

Outside of fashion my own feelings about espresso have changed dramatically over my career. It was all I knew coffee brewing to be for the first couple of years, and then I fell in love with brewed coffee and espresso seemed so awkward, so difficult and often so unrewarding in comparison. I was probably a bit too negative about espresso – I vaguely remember the idea of writing an article where Chris Tacy would defend espresso, and I would be all about brewed coffee.

Considering Chris’ fairly recent post this might seem a little odd. That particular conversation has gone down one path and I want to talk about something else – which is how much I enjoy brewing espresso these days.

I was recently running a couple of workshops at the Caffe Culture tradeshow, and I realised that explaining my own evolution of emotional attachment to espresso could be a good structure to explain how I now think about brewing.

This all starts with walking offstage in Berne in 2006 in the WBC finals.  I was delighted to be up on stage, I had a lot of fun but I definitely remember the feeling of walking off stage and feeling that I had absolutely no idea how to brew espresso.  I knew I had great raw materials, well roasted, and some nice kit to brew on.  I had been unable to push and prod my espresso into tasting how I wanted it to – I simply didn’t have the knowledge to exact the change on the cup profile that I wanted.

Looking back – I was serving fairly high dosed, fairly light roasted, underextracted and strong espresso.  It was sour, and no matter how much I slowed down the shot I couldn’t get it to sweeten up the way it had in practice.   Maybe I will come back to why later….

Espresso was so dispiriting for so long.  We end up using words like art for brewing, which I think is probably wrong.  Brewing is execution of task.  It should require craft, but not art.

Let me put this another way:  If I walk into your shop and order an espresso – how confident (as a percentage) would you be that the next shot you pull and serve will represent you, your shop and your coffee properly?  Be honest….

For a long time I felt that my own number was probably around 40-50% on a good day.  Sometimes espresso sucked, and I didn’t know why.  After the WBC the stress bumped up a notch – if I was serving coffee somewhere people would walk up with expectations and I rarely felt confident that I met them.

This nature of espresso is why there has been so much bullshit, myth and voodoo around for so long.  We explain things by looking for trends rather than explanations.  A classic example of this would be our approach to coffee grinding an humidity/weather.  I would argue that the weather will affect your grind, mostly by affecting how busy you are.  This impacts how hot your grinder is running, resulting in a grind change.  I simply haven’t seen a change in grind happen quickly with a rapid change in moisture/humidity. (I could imagine a gradual change would make more sense.)

I don’t want to get into a humidity debate – just an example of causation vs correlation.  Another might be the advent of naked portafilters.  At the time people were suddenly raving that they produced espresso with more body, more intensity, more sweetness.  The explanation was simply that people were pulling shorter shots, that looked normal volume because of the additional crema, but doing it so fairly slowly – they were pulling reasonably extracted ristrettos, they’d changes the recipe rather than the absence of a portafilters bottom somehow impact the extraction that occurred inside the basket above.

I’m getting off topic – I want to come back to why I enjoy espresso more.  I enjoy it more because it I have a functional recipe that I can replicate accurately, and relatively easily.

No doubt Vince Fedele had a big impact on this – with both the Mojo and the also the VST baskets.  I’ve already seen some strange things written about them, and what they do, so perhaps it is worth explaining a bit more.

We brew espresso by controlling flow rate using the resistance of the coffee cake.  Traditionally we think of two variables to control that resistance:  grind and dose.  Using these we can control how long the contact time is for a fixed volume of solvent (water).  The combination of contact time and quantity of water basically decide how much we extract from the coffee.

We didn’t factor in a third factor into that resistance – the bottom of a portafilter basket.  We tend to think of their job as being about filtration rather than impacting contact time.  However, they ought to be treated as an additional constant of resistance.  Most baskets are built with the majority of end users in mind.  Most end users – and that is a very large majorirty – are dosing around 7g per shot of espresso/14g for a double.  With a relatively small dose you need to grind pretty fine to get your desired contact time which has the benefit of exposing an increased surface area which makes the coffee easier to extract.

Higher doses – 18g+ came about somewhat by accident.  They were a product of grinding to order and using a basket to measure a dose of  ground coffee by volume.  The increase in dose meant additional resistance.  The basket resistance, plus the higher dose resistance meant we had to grind coarser.  This coarser grind made the coffee a lot harder to extract.  We found we liked the texture and strength of a higher dose of coffee, and this trend went further with people pulling shorter and shorter shots.  This meant we had less and less water to use in our extraction.  End result = underextraction.  A byproduct of this was darker roasting to help balance out the sourness of the underextracted cup.

The VST baskets are great because they do a few things exceptionally well.  They have less resistance the larger they are.  This means that you can grind much finer than you otherwise could before.  This means you can extract more.  This is good news.

Secondly – the way they are manufactured means that they are extremely consistent – an exact number and size of uniform holes. This means that if you have a 3 group all the baskets will act exactly the same.  Plus they’re built to be much thicker so they’ll last a lot longer.  This is a bit of a simplified explanation but hopefully you’ve all read the article in Barista Magazine that Vince wrote because it was great.  (Best edition of the magazine ever too!)

I haven’t really explained why this means I like espresso more.  I should probably do that now.

If I take a great espresso machine, and a VST 21g basket, and I put 20g of coffee into it and in around 28s I produce around 32g (brewing at 94C) then I know with 90%+ confidence that it will taste how I want it to.  That is, to me at least, pretty exciting.  It also massively reduces the stress of espresso.  I know that it won’t be a perfect shot, but it will be very tasty and something I’d be happy to sell.

I’ll be honest – the above recipe is where I always start.  I won’t taste it till I get there – because I don’t want the first 2 or 3 espressos I drink each day to suck.  I’m all for tasting bad espresso for diagnostic learning, but I’m also all for actually enjoying the damn drink.

Based on what I taste I might make changes, adjusting how I extract based on the cup.  If things are a just a touch out of balance on the acidic front then I will likely do something pretty simply like use a little more brew water to up the extraction.  34-35g of liquid from that dose will still have great mouthfeel if you brew it properly.  Very rarely do I need to make that change.  I know what kind of extraction yield I have, and I know what I like.  I’m not going to be prescriptive in that – the point of analysing espresso extraction (for me) is to understand what I enjoy, how I can change things to get there and to define the boundaries of good coffee for the recipe I am trying to make.

I’m sure some people will be horrified by the simplicity of the brewing.  Shouldn’t I spend longer “dialling in”, fighting my flawed grinder (because they’re all flawed), and burning out my palette to emerge the battered hero of espresso brewing, victorious in my reasonably good espresso which I might then struggle to replicate with any great consistency?  It amused me to see that Schomer (from his last blog post) 1 seems to revel in the challenge, in the difficulty, and sees it as being an important aspect to treating coffee brewing as a craft.  I don’t agree, but it is ok if you don’t agree with me (or with him).

I’ll be honest – I think weighing scales are an essential part of a good, streamlined, efficient dialling in routine in the morning.  I think they’re a great quick QC tool when you’ve got a tired tongue.  I think they’re a great training tool.  Volume measurement being so common and so flawed is one reason that I struggled with espresso for so long.  I think it is a very good reason that many other people struggle with it.  I think it is crazy not to spend £10 on a little tool that can do so much good. Do we really want to keep struggling with it to preserve our own egotistical version of our craft – or do we simply want to sell people delicious cups of coffee? If we can get past the basic challenge of consistent execution then perhaps we can get to a place where we can be much more creative with coffee.

I’m not saying that I can now brew perfect espresso every time.  That would be as idiotic as using the word perfect to begin with.  I find brewing espresso much easier than ever before, and I drink more espresso that I enjoy than ever before.  There are still many challenges with it, and a lot of things we don’t understand.  There are other factors impacting cup quality in ways that are hard to quantify – can’t help but constantly come back to grinders here too.

I promised a while back that I’d stop going on about weighing espresso.  I’m not going to apologise for breaking the promise, and I hope other people identify with my own to and fro with espresso.  It is still a completely frustrating thing in many other ways – if you listen to the last podcast with Tim Wendelboe then we both talk a little about this.

  1. There is so much in that article that I’d like to respond to, but I don’t really want to get into an online blog tit-for-tat blog tennis match  ↩︎

Restaurant Coffee

I don’t usually post much work related stuff on here, but taking this photo it struck how ludicrously easy it can be to do a great coffee service in a restaurant. This photo was taken in a restaurant in London called Trinity. Trinity is a small restaurant in South West London, in a fairly residential neighbourhood. A few months ago they took out their espresso machine and replaced it with brewed coffee.

Looking at the photo is seems almost ridiculous. They have a great equipment setup there, and it cost a lot less than even a cheap 2 group. It also takes up a lot less space. They offer different, contrasting coffees. The staff are passionate and informed about the product. 1 They consistently serve really, really tasty coffee. People like really, really tasty coffee.

This doesn’t mean it has been easy. People still come to restaurants expecting to end a meal with an espresso. I think it takes some bravery for a restaurant to admit that espresso is incredibly difficult to do, and instead choose to do something of which they can be proud every time it is served. Inevitably success here comes down to service more than it does product, and I was really impressed by how thought out their approach was.

This isn’t new globally – but it is new to London. There are restaurants out there that are willing to invest in staff, equipment and training. There are many more restaurants knowingly serving an item on their menu that isn’t very good. In fact they know it is pretty bad. Many are too scared to make the change – I hope Trinity pave the way for others to follow. As a consumer and as a coffee professional I’d love to see more great coffee coming out of restaurants.

  1. Doing staff training here is so much fun. We brew coffee, talk about it, argue preference and I answer lots of questions. I love it! That and the technical side of the training is easy to do, and the staff remember everything and just do a good job. The same is sadly not true of espresso training.  ↩︎

Brewing Espresso at Altitude

There has long been discussion about what happens when you brew espresso somewhere at relatively high altitude. This has become, and will become even more, relevant as the WBC is taking place in Bogota this year. Bogota is the third highest capital city in the world, some 2625 metres above sea level (approx 8,600ft).

At this altitude water will boil at 91.2°C/196.2°F – below the 93.5°C/200°F that the Aurelias will be set to. What follows is mostly personal opinion 1, coupled with a possible experiment that might answer some questions.

When we’re brewing espresso the system is under pressure (9 bars mostly), rather than the much lower atmospheric pressure. One of the unique aspects of brewing under pressure is that water is able to dissolve a lot more CO2 than it usually can at atmospheric pressure. When the coffee liquid leaves the basket we see that it is unable to retain that CO2 which forms bubbles that get trapped by various surfactants as a foam: crema.

People will often remark that at altitude the coffee acts like it hasn’t had a chance to rest/degas. The espresso tends to have very large bubbles, and lacks strength – often disappearing very quickly. This is, of course, similar to brewing very fresh coffee (up to 48-96hrs post roast) at sea level.

What doesn’t make sense to me is that surely CO2 would be more likely to be drawn from the coffee bean when stored at low pressure than at higher pressure?

My guess (and it is a guess) is that the pressure change from the bottom of the basket to atmosphere is much larger than normal when brewing at altitude. I would guess that the saturation point for CO2 in water at 2625m is significantly lower than the saturation point at sea level. The liquid loses more gas, and we see this as bigger bubbles. With foams in liquid the strength is dependent on bubble size (the smaller the stronger – think good milk foam), so these larger bubbles of crema will disappear faster.

What does this mean for competitors? Here is my advice:

Bring scales. I know a lot of people don’t like it (though I don’t really understand why), but your espresso volume is going to be radically different for an identical flow rate at sea level. Know your brew recipe before you come, and before you start freaking out about how things taste, check whether you are brewing on spec. Espresso is a recipe that is based on weights and flow rates. Going by eye is tough. I’ve tried, when I was there in 2007, and it took a while before things made sense!

Pulling shots in Bogota

Another question remains – should espresso be aged longer for brewing at altitude?

This is a good question, and one I think we need to do a few experiments on. Ageing espresso will certainly reduce the amount of CO2 left in the coffee beans, but surely at the expense of some loss of pleasing aromas and the potential development of negative flavours. I’d like to run a two way experiment, but it needs participants who have access to coffee machines at different altitudes.

Take two bags of espresso from the same roasts/blending batch. Store one at sea level, store the other at high altitude. Ideally in similar temperatures. After 10 days bring both back down to sea level and observe variations in volume for a fixed weight of coffee, liquid and brew time. Based on my amateur theorising above – there should be no detectable differences, or – if anything – the coffee stored at altitude might have less crema/volume when brewed.

Then take two bags of identical espresso and store both for 10 days at sea level. Then brew one at sea level and one at altitude. Record variations in volume for fixed weight of coffee, liquid and brew time.

This way we’ll know whether the issue is ageing of brewing. I would predict that when brewed identically the high altitude espresso should be just as delicious as the low altitude one – but I am very happy to be proven wrong.

One aspect to consider is when the brewing liquid might reach boiling point. If someone is pulling very fast shots, where the brew water doesn’t lose much heat to the coffee – then I’d expect to see some issues towards the end of the shot as the exit liquid from the basket will be very close to boiling, if not boiling at high altitude. Properly brewed espressos shouldn’t (in theory) see the same problem. Anyone have video of a naked portafilter at high altitude?

Comments, thoughts, accurate science and brutal critiques of the above welcome!  Thanks to Brent Fortune for setting my brain off!

  1. Warning: Amateur Science Alert!  ↩︎

Where are we with pressure profiling?

David Schomer’s comments on pressure profiling this week haven’t been particularly well received it seems.

This is quite frustrating – he’s raising an interesting point, but has done so in a way that allows it to be torn apart due to his presentation. You could say he’s unable to back it up, he’s making such sweeping statements topped up with a self confidence easily labelled as arrogance. 1
Continue reading “Where are we with pressure profiling?”

  1. What actually annoys me more is the pseudo science is his writing. ” the preservation of these unstable molecular structures that constitute coffee flavor/aroma” being an example. Ah yes – these unnamed, mystery structures of wonder, so unstable that they’ve somehow survived temperatures in excess of 400F during roasting, but still so unstable that 1F variance in water temp ruins all!  I should also add that in person he’s been nothing but friendly to me, so I feel a little mean writing this.  ↩︎

Dialling in without timings

Just a quick post – not really designed to be a how to, more a little anecdotal incident that I wanted to share. It is interesting how Extract Mojo starts to change the way you think about espresso.

This morning I was chatting to Jess as we were pulling shots (for in house consumption I should add).  The coffee wasn’t tasting great and we started talking about dialling in  and what we would change.  I like having a timer around for dialling in, aware that I am woefully inconsistent when it comes to mental timekeeping and it is a key variable in dialling in – brew time has been something I’ve been trained to focus on.  Couldn’t find the timer, so instead we grabbed the scales. Continue reading “Dialling in without timings”