The internet is full of information, though it is also full of keyboard heroes, and has something of an issue with its signal to noise ratio.  Identifying who is a useful purveyor of information is tricky and, while there is growing use of indicators in forums, often it is he who shouts loudest that wins.

I started blogging to chart my own learning, and to share what I found out with others.  Sometimes this information was very useful, and sometimes it really wasn’t.  With the videocasts the idea was to share techniques that people could use at home that would be repeatable and help them make better coffee.  It was argued (quite correctly) that my Chemex technique was flawed – that the top of the cone was likely underextracted compared to the coffee at the bottom of the cone.

I was wrong, and this was a good thing – it was useful because I learned and hopefully others reading too. ¹

It could be said (and it was) that I shouldn’t abuse my position and ‘release’ techniques that hadn’t been completely tested, because I could (in theory) quickly spread misinformation. ² While I saw the point I couldn’t help but feel that if I had to reach some sort of perfection then I would never ever get there on any technique.  I don’t think we’ll ever reach close to perfection.  If I am brewing coffee in ten, or even five, years time the same way I am today I have failed as a professional or we have failed as industry.

Good scientific method is about throwing an idea out there to find out what is wrong.  The internet is a great way to communicate ideas, to spread them.  Being wrong is a very important step in learning and needs to happen regularly.  I am sure each and every one of us is appalled by something we used to do differently even a couple of years ago.

If you say you have the perfect technique – I don’t believe you.  If you say you have the perfect espresso blend – you’re going to look stupid very soon.

Distrust those with all the answers.

Test other people’s ideas and techniques.

If you disagree then throw your opinion into the mix.  If you agree then do so too.

Don’t take what I say, or what any other (coffee) blogger says at face value because I/we/they are going to be wrong. Often. And that is ok.  You only look a fool when you are wrong but refuse to accept it.

1. Because it was aimed at home brewing I had been trying to come up with a technique that could be done without special equipment – I am sure there are more chemex’s in homes than pouring kettles.  I hadn’t meant to direct the method at the industry.  I really don’t want this to sound like an excuse, though it probably does already.
2. I should be clear in pointing out that selling information does change all this a little

This morning I got up early to fly over to Dublin, to the CatEx show there.  Apart from catching up with Stephen, and lots of other lovely coffee people, and catching a little of the Irish Barista Championship, I was really there to see the guys at Marco and the new machine they had on their stand.

I am not going to be able to get very far in all this without talking about the Clover first.  The reason that the Clover got me excited initially was that it was going to be a potential way to keep promises¹ made when serving coffee.  Some people hated the amount of control it offered (deeming it soulless automation), while others got excited about dialling in coffees.  No doubt the profiling it offered really appealed to the people who bought the company.

After the Clover disappeared from the market the industry seemed to take a step back and then dig out all its old coffee brewers and start playing with them again.  More French Pressing, Vac Pots popping up everywhere, and every self respecting coffee nerd having a Chemex in cupboard.

While researching different bits and pieces for a potential cafe Anette unearthed the Quooker Tap. Nice idea, but some problems when it came to coffee!  I began to wonder if it was possible to add a mix tap to add cold water, maybe drill a little hole in the end of the spout and put a probe in and live mix a desired water temp.  Stephen, Anette and I hammered the idea out a bit more but didn’t really know what to do with it.

At the Caffe Culture show last year we got chatting to Paul Stack from Marco about how possible the idea was.  His proposal was awesome – they would take on the project and build us one.  For them it was a great research project, and they are a bunch of wonderful coffee obsessed people who immediately understood where we were coming from.

Paul came over to the roastery in August last year and we went into greater detail about what we wanted.  I demanded typically ludicrous things:  I wanted a built in scale, a live temperature display, I wanted to be able to jump between temperatures for different coffees quite quickly.

During development Paul sent across piles of data and I was extremely impressed in the consistency of water temperature delivered – a swing of around 0.2°C with their testing kit once the boiler had stabilised.

What I worked with today is still very much a prototype – it will be developed a little more before it is shipped over to us for further testing.  Hopefully a drip tray, a built in timer unit and a few other bits and pieces will be added soon.  I am not going to go into great detail about how it works operationally because it is likely that that will change to something a little more intuitive.  Before use it requires switching to ‘BOOST’ mode that cycles water right up around the font to heat and stabilise the water lines for consistent delivery.  We’re going to work on more intuitive movement between brew temperatures and I probably don’t need to explain how to use a scale.

Water delivery speed was relatively slow – good for Chemex, and not too slow to be frustrating when making a press.

Some pics (remember this is a prototype!):

Marco Boiler

Scale control and water delivery

Live brew temp

Built to fit a large Chemex underneath!

All credit to Marco for working towards a very creative, versatile boiler that would suit people who want to embrace all brewing methods yet still want control and repeatability.

Initially the plan was just to build one for us but I think the reaction it has recieved at the one tradeshow alone means that they will be looking to produce more units if the demand is there.

For those interested I’d recommend e-mailing Marco, and they will keep those interested up to date on the boiler.

Oh, and it doesn’t have a name yet – suggestions welcome!

If people have thoughts or questions then please post a comment and I will do my best to answer.

1. there is a big long post coming baout making and keeping promises with brewed coffee – soon!

Videocast #3 – Chemex/Pourover from James Hoffmann on Vimeo.

For more information there are some notes on the Square Mile blog.

Comments and discussion always welcome.

Gradually, over the last few weeks and months, I have realised that I am really, truly learning again. It is a great feeling. Competition used to be my way of stepping back and being forced to reassess what I did and why, and my year as champion had amazing bursts of learning such as origin trips.

Back at work again it has been a pleasure to start to develop my palate all over again and start to work out what I am tasting when I pulling shots. I’ve never really able to taste as clearly what a particular coffee is doing in a blend, or to understand exactly what a coffee brings to a blend when pulled with all the variation that humans (especially me!) bring to brewing. All of this is a great reminder that I have such a long way to go, and I love this part of the process.

I also realised today that my Chemex brewing technique has been slipping and I am not getting things right – time for a grind reassessment, as well as a technique check. I am losing the top notes and I want them back!

In other news I have no idea how coffee suppliers stay trim, as I am already starting to worry about my inability to refuse delicious treats when dropping in. Looks like I will have to take up some serious form of exercise!

The first thing that upset me was just how hard London’s water is. Out of the tap I get 410ppm, which is pretty hard. This means it is not ideal for brewing coffee as it is less “hungry” for new solubles than softer water. I didn’t realise until I started testing just how badly it was affecting the coffee.

Testing some of Tim’s coffee brewed on the skinny Chemex

I was struggling to get into the Golden Cup zone of 18-22% extraction which, through years of filter brewing, is considered a suitable target. Different countries might like different strengths of coffee but they all generally like 18-22% of whatever dose that is.

I have know switched to bottled water for brewing (with a much more attractive TDS of 130ppm) and the coffee does indeed taste much better and my extraction percentages are up even though I haven’t changed the grind or dose. I had gotten used to a very coarse grind on the Chemex (after being advised by Kyle in Intelli.la) but have slowly been bringing it finer to get the percentage up. I will keep doing more but wonder how many other people out there have TDS meters and whether they have compared their brewers with different grinds and doses and compared the cups after.

To this end I’ve done a little spreadsheet that negates the need for a brewing chart as the maths is built in. It works on 2ml of water being absorbed by each gram of coffee but you can change that too. Input the amount of coffee you use, the amount of water you brew with and then TDS measurements. I’ve left columns in there for other useful data – such as brewer, coffee used and notes on grind settings. I probably should have found a way to include a cupping score/notes but haven’t. If anyone else fancies having a go then do download it and let me know how you get on. Once I have enough data I will post up about my Chemex experiments.

Thoughts and comments welcome….

TDS Testing Spreadsheet


downloads

UPDATE
Mike Khan from Bunn sent me his spreadsheet which does percentages and graphs for each brew you do.
Mike’s TDS Calculator


downloads





Thank you Mike!

Now I love my Chemex – it is my comfort brewer at the moment, though the vacpot is getting tempting (I just worry about committing to the technique to raise myself to the level of the barismo vac brewer kung fu). However I can’t stop worrying about the paper. I rinse religiously, and often wonder what it is keeping out of my cup (for good or bad).

Brewing some fine coffee this morning

What threw me is something I hadn’t considered up until this point – the way that the paper affects the flow of water through the coffee. I haven’t brewed much in the past with gold/titanium filters so I put my hands up as inexperienced. As I’ve said previously I have been using a much coarser grind with the Chemex, but the Kona has taken me a fairly long time to dial in the grind as the metal doesn’t provide the same resistance to the water that paper does. To get a decent brew time I had to grind finer than seemed right, and the cup was indeed a bit ropey. I am still not entirely convinced I’ve got it but I did get a very sweet cup from the Collective’s Daterra Sweet Collection.

I am brewing at 60g/l at the moment and would appreciate any input from people a bit more comfortable/experienced with them than me. Also I’d be curious if people have any particular techniques for pouring the water.

After some comments in the thread about using scales to brew my Chemex on brew temperature I decided to perform a few rounds of experiments. Simple really, I just placed a probe (K-type, not ideal but it will do) into the bed of coffee, poured over the water and waited to see what would happen. The first test gae me an unexpected result.

Brew temperature of a Chemex

What I expected was a steady decline in temperature during the extraction, and over a couple of minutes losing a fair few degrees, due to the area of steeping coffee being quite large. When the probe was in at the top of the brew the total heat loss was about 2C. Not much at all. What was interesting also was the temperature gradient throughout the liquid. At the start it was a couple of degrees from the top of the brew to the point of the filter cone and over brewing that stretched out to about 4 or 5C.

I’ve only done this experiment a few times so if you have the kit and a few extra minutes to spare I’d love to see it replicated – the coffee coming out isn’t much affected by the probe so it isn’t a wasted cup in the morning.

To completely and utterly hypothesize – it seems the floating crust of grounds does wonders for insulation, possibly with the help of CO2. In the next round I’d be tempted to stir and skim like a cupping bowl to see if this accelerates the cooling.

Thoughts anyone?

I am pretty much a 60g/l kind of person when it comes to brewing and, after I was rightly schooled by Kyle Glanville whilst in LA, my grind for the Chemex is pretty coarse. However I just can’t let go of the obsessive chasing of detail. The moment’s where things just come together by mistake are few and far between for me, so I obsess. I tend to use a larger Chemex so when I only want a large cup it bothered me that I didn’t know visually exactly how much water to add, or when I had added enough without guesswork. And guesswork just won’t do. So now I tend to put the chemex or press with the coffee in on a scale, tare it off and then pour the correct weight of water. I dislike transferring water from kettle to measuring jug to brewer so this seems the only sensible way.

It seems so obvious – and whilst no one told me to do it like this surely I am not the only one? Is this too geeky?

It has become my standard way of making coffee at home if I am relaxing or working. Part of the slightly unscientific way in which I use it bugs me. I am never really quite consistent with my dose, and the period of time where you soak the grounds in a little water (the “bloom” as Chemex likes to call it) varies a little as well.

I like the coffee I get out of it very much, and it is a very pretty vessel. It could just be the coffees I am using with it but I do tend to get cups with great mouthfeel, lovely sweetness but often not quite the nuance and character I know the coffees are capable of. Don’t get me wrong – I love the coffee it makes, yet I worry I am doing something wrong or am missing a trick somewhere. That or maybe that’s just the kind of coffee it makes.

Comments from fellow Chemex owners very welcome. What kind of dose/grind are you using?