hammertoe

A coffee-loving software developer.

I can't remember when I first encountered Vietnamese coffee. Alas I've never been to Vietnam (a place I'd love to go!), so my guess is it must have been a restaurant somewhere at some point. But then after that for a few years there was a cafe called Hanoi Coffee Company in central Bristol. I used to frequent regularly just to get a hit of this lovely drink.

This post is part of my coffee series of posts, a full list of which is available here.

Vietnamese coffee is traditionally served with condensed milk. The condensed milk is placed in the bottom of a glass cup, and then a metal drip filter called a phin is placed on top of the cup. Course ground coffee, often with chicory in it is put in the top and hot water poured in. The water drips through the coffee and onto the condensed milk at the bottom, giving a lovely two-tone drink. It always seems slightly decedant to me, maybe because it reminds me of cocktails in which the different coloured spirits are carefully poured on top of each other.

You can then stir the coffee in with the condensed milk, which provides both a sweet and milky aspect to the drink. The coffee is short and strong, a bit like an espresso. I generally drink my coffee black when I drink a filter or Americano coffee, but this I really like.

I used to hop on my motorbike in the evening and ride down to the centre of town, get a Vietnamese coffee and sit in Hanoi Coffee Company and watch the world pass out the window. A sort of desert, if you like. Alas they have closed down since, so I need to hunt around for somewhere else... or maybe buy a phin and make it myself. They are only a few pounds to buy online.

So why chicory? Apparently this isn't actually a traditional Vietnamese thing, but came about by a cafe in New Orleans called “Café du Monde”. A lot of Vietnamese immigrants to the USA ended up in New Orleans. I guess there is a common French connection there. They found that this particular coffee matched the flavour they were used to back home, and so it kinda stuck. Now the yellow-ish / orange tin of Café du Monde coffee has become pretty ubiquitous with Vietnamese coffee worldwide.

But, no, really... why chicory? Well you have to be a subscriber to find out below ;)

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So, I'm about to start a series of posts on machine learning and artificial intelligence. This set of posts will be somewhat technical but, the idea will be to introduce people to the concepts of machine learning and artificial intelligence and to de-mystify it a bit.

This is a post in my series on machine learning and artificial intelligence. You can find more posts on this topic at the main index.

So hopefully the first few articles at least should be followable by people without any specific technical or programming experience. As the series progresses I will start to bring in python code showing some examples of using machine learning for various tasks.

So the first thing to cover... what even is it? We hear so much about artificial intelligence and everything from Terminator to Teslas come to mind. Some may even remember the 1980s film Wargames in which a young hacker (Matthew Broderick) accidentally breaks into a US defence computer controlling nuclear missiles. The film culminates with Broderick playing a game of tic-tac-toe with the computer and it learning that the best way to win is not to play at all. And hence nuclear armageddon is averted. This is a great simple example of machine learning, and an example I'll come back to.

Generally, in 'classical' computer programming, a programmer writes a series of instructions for the computer to follow. Those instructions are explicit in what to do and contain logical flow: e.g. “If the temperature is above 20 degrees then turn the heater off”. This code is pretty simple to look at and reason with. But it requires the programmer to know what the logical statements are. In essence, all computer programs take some kind of input and produce some kind of output. In this case the temperature is the input, and the state of the switch that turns the heater on and off is the output.

In this case, it is pretty easy. The code would look something like this. It is a function that takes an input temperature and returns either 1 or 0 to represent the state the heater switch should be.

https://gist.github.com/hammertoe/7524e935cfa05cb652ff67cd58be0dd0

But what if instead we wanted to instead code something a bit more generic e.g. “If the temperature is too hot then turn the heater off”. How do we define “too hot”? A computer is a pretty 'unfeeling' object. How does it know that “too hot” even means? Well, with machine learning we can try and teach it what that means.

This could be achieved by a branch of machine learning called “supervised learning” in which we give a program a set of known inputs and outputs called the training data and get it to learn the “bit in the middle”. Here is what the training data could look like.

https://gist.github.com/hammertoe/20366fa70acc034e7324a5eb2342b8c8

Can you spot the pattern here? Yes, it is what we described before, that if the input temperature is 20 or below, then output a 1, otherwise output a 0.

With a machine learning algorithm we could train it to learn the pattern so that we don't have to explicitly code the rule. This might seem strange with such a trivial example, but where machine learning excels is when we have much more complex input data and patterns we might not be able to spot as humans. What if our input data wasn't just temperature, but was temperature, humidity, number of people in the house, time of day, output temperature? And the output was what we feel whether the heater should be on or off? That would be very hard to try and write rules for explicitly. But if we had a whole lot of training data taken from actual human experience then the program could learn what the rules are. The goal is for it to learn a generic set of rules that it can then apply to input data it has not been trained on and come out with the right answer.

Hopefully this 'sets the scene' for what it is I will be writing about in these posts and give people a starting point.

I like coffee... no... actually... I LOVE coffee. So here is a list of all the posts I've written on Coil about coffee. I'll be updating this list every time I post a new article about coffee, so there is an index here.

Coffee Making Technique

Coffee Brewing Methods

This post is part of my coffee series of posts, a full list of which is available here.

The Moka is probably one of the most iconic traditional coffee makers. Found in the kitchens all across Italy and The Middle East and further afield. It is a design that has lasted decades virtually unchanged.

My intention with blogging on Coil was to write about machine learning and artificial intelligence, but I dipped my toe in with re-publishing an article I wrote a few years back on “levelling up” on coffee making at home. There was so much feedback on Twitter about it, that I thought maybe this might end up being a mix of AI and coffee... what could possibly go wrong?! But it gives me a chance to mix up some 'heavier' articles that require a lot more prep with some shorter ones about various aspects or tools of coffee.

So back to the Moka. It was invented by an Italian engineer named Alfonso Bialetti in 1933. And available in a variety of sizes for making from 1 to 12 cups of espresso-like coffee. Although sometimes referred to as a “stove-top espresso maker” the coffee is not quite as strong as an espresso and produced under lower pressure than an espresso machine.

I've owned two of these type of coffee makers over the years, one a traditional one, and one of them (a “Mukka”) designed to take milk and make a cappuccino-type drink. The milk-based one didn't work all that well. And alas ultimately they both met the same fate... that was they had been left with some coffee grinds still in them my mistake and that has gone mouldy and worked its way into the aluminium. No matter how hard I tried I couldn't get it out. So, rule number 1... actually this applies to coffee in general... is clean up!

I once 'dated' (too short to really be called dating) a Moroccan woman and the first time she invited me back to her place she asked if I wanted coffee. This was in London in a tiny apartment. At the time most people in the UK drunk pretty horrible instant coffee. She brought out a Moka and made coffee in that. Alas for various reasons the relationship with her didn't continue... but I always remember that Moka pot.. and my relationship with coffee!

A Moka pot works by filling the bottom chamber with water, putting some coffee grounds in a filter basket and then screwing the top and bottom together and heating it on a stove. The great thing is that heat source can be a gas hob, electric hob, open fire etc. So great for use camping. They are pretty robust (just keep them clean, as above) and can be chucked in a bag. That said they are reasonably heavy in that they are solid metal.

The steam pushes the hot water up through the coffee grounds and into the top chamber with a satisfying gurgling noise.

So that is the Moka, a traditional favourite. I'll be writing more about various other methods of brewing coffee in future posts, stay tuned!

This post is part of my coffee series of posts, a full list of which is available here.

OK, so I was asked by a colleague about how to ‘level up’ in the coffee game. He drink instant and wants to dip his toe into something a bit better. I’ve had a blog post along these lines rattling around my head for a while, so here it is.

Firstly, let’s set out some expectations here:

This is NOT a blog post on how to make the most amazing coffee in the world. For anyone reading this that can make a better coffee, then that is great. This post is about how to dip your toe into making significantly better coffee than instant, but without having to invest vast sums of money in equipment and time in technique. Yet on the same hand, I’m not advocating some press-and-forget system. The idea is you might learn something about coffee and get to appreciate it even more.

But a disclaimer here, I am not going to be held responsible if this does set you on a slippery slope of coffee love, and 2 years down the line you are divorced and homeless… living in a cardboard box with nothing but a £12,000 La Marzocco Strada to keep you warm. Muttering about dissolved solids to any passing stranger.

So, the summary here is that I’m recommending you spend about £60 in equipment and get a grinder and Aeropress and buy some decent beans from a local roaster and you will be set. This is, as always, a personal viewpoint. It is just my idea on how to get started, none of this is gospel and I’ve tried to keep this simple, so may have glossed over details (or I just don’t know them!). We are going to be making a long filter-like coffee, not an espresso… that is a whole different story and does require investing more in equipment to get results.

The details

There are three main elements to making decent coffee:

  • Decent ingredients
  • Decent equipment
  • Some knowledge and technique

Now, as I said above, ‘decent’ and ‘some’ are subjective. Anyone who has spent any time on an internet forum for anything, be it coffee, cars, stereos, computers… will know that you will always get the same pattern:

Person 1: “I use X to make coffee / oil in car / stereo interconnects”

Person 2: “No way! I wouldn’t use X to make coffee for my dog / oil my bike chain / wire my doorbell! Use [costs 10x as much] Y instead!”

Inevitably it is bravado and one-upmanship, but also life is subjective so everyone will have a different view. Not only that, but they might be chasing the final few percent of performance from whatever they are doing. I’m just trying to get you from 30% to 80% here, not bump you from 98% to 99%.

Ingredients

There are two main ingredients in coffee:

  • coffee beans
  • water

Wait?! What?! Water?! Well, yeah… considering most of coffee is water, then it does matter. But to be honest for right now, I’m not going to worry about it in this post. There is an entire book dedicated to water for coffee if you are interested. But lets just say, much as hard or soft water affect how much detergent you need to make suds or how clear or murky your tea is, it also affects how the oils and flavours from coffee are extracted from the beans as part of the brewing process. So whether you use a water filter (Britta-type thing) or use bottled mineral water may change the taste of your coffee.

Coffee beans. OK, so here is where we start making a difference with coffee. The majority of the coffee you buy in the supermarket will have been roasted many months ago. Coffee goes stale. Very quickly. And if coffee is ground then it goes stale quicker. There is a much greater surface area and so it goes off quicker. Even leaving ground coffee for a few hours and it will go stale.

So what you want to do is buy coffee beans that have been roasted recently (normally within the past few weeks) and then grind the beans just before you use them. If you grab a bag of ground coffee from the supermarket and open it and smell it. Now go to a local independent coffee place and ask to smell the beans there… you will see an amazing difference. The smell from fresh beans really is a world apart. And seriously, do this. Don’t feel weird about it. Any decent independent coffee place will be more than happy to let you smell a handful of the beans.

So where to get the beans from? Try and find a support a local coffee roaster, or coffee place if you can. I’m pretty spoilt in Bristol as there are a number of local roasters here (Extract Coffee, Roasted Rituals, Clifton Coffee, Two Day Coffee… I’m sure I’ve missed some). But you can also buy online from a number of places, e.g.

Generally you’ll pay about £8 for 250g of coffee. And depending on how much you order you might pay a few quid in postage. But don’t buy so much that it goes off. If you look at the date on coffee from these people you will see it was likely roasted within the last week or two. These will be coffee beans that have been sourced from specific growers with care. The majority of your supermarket coffee is bought and sold on the commodity markets where quality is a secondary concern.

Those places will have all sort of different beans there, from different suppliers around the world. Don’t worry about which to get, just pick one. You can try a different one each time and see if you have a favourite. But for now, any you pick will be a world of difference from your instant coffee. Some even do coffee bean subscriptions and they will automatically send you a different one to try each month.

Equipment

So, how long is a piece of string? How much should I spend on a car? You can spend very little, or a fortune on coffee making equipment. As I said above, I’m just trying to get you going and better than instant. So we are going to go for something that can make a long filter-like coffee. There are two main options for this, a pour-over (like the Hario V60) or the Aeropress. I’ve only got experience of the Aeropress so that is what I’m going to recommend here.

The Aeropress was made by the people that made the Aerobie flying disc… remember them? Whilst is bills itself as an ‘espresso’ maker, it very much isn’t. It is best for making a mug of coffee. It costs about £25 and comes as a kit with some filter papers and some other bits (stirrer, funnel, etc). In short you put a thin paper filter in the bottom, you set it on top of your mug and put some ground coffee in it. You then pour hot water in the top and give the coffee a stir and wait a bit then plunge down the plunger and the coffee is pushed out the bottom into the mug. I’ll go through the technique in detail further down.

You also need a way to grind your coffee beans. There are two main types of grinder, a blade grinder and a burr grinder. The blade types really are pretty useless. Don’t buy one. They use a spinning blade to chop the beans, the problem is the beans end up ground to various levels of coarseness and it is hard to repeat the same.

The other type, Burr grinder, is like a pepper mill and a the beans pass through a set of metal burrs that grind the beans to a set size. The grinder can be adjusted to how fine it grinds. If we were talking espresso here, then I would say the grinder is as (maybe more) important than the espresso machine. I would be recommending you spend several hundred pounds on one. But for Aeropress coffee, you don’t need to grind as finely or accurately, so a cheaper one is perfectly fine.

The grinder I have and can recommend is the De'Longhi KG79 Professional Burr Grinder. Which is about £40-50 (currently £33 on sale!). It has a timer on it, so you can hit a button and it will grind the amount you need. The only slight criticism is that it can be a bit messy when you tip the grinds out from the grind container into the Aeropress. There are no doubt other good ones out there, this is just one that I happen to have bought and fits the criteria of being cheap and doing the job in hand.

Technique

Again, as with most things in life there are those better at something than you, and those worse than you at something. There is always something to learn, and there is always something to teach. My point of this post is hopefully that you learn something… but I’m not professing to be, or to make you a Coffee Jedi.

So what I present below, is how I make a decent cup of coffee using the ingredients and tools above. I’ve also recorded a short video at the bottom showing it all together. If you want to get inventive there is actually a World Aeropress Championship which publishes their recipes online.

  1. Stick the kettle on. Coffee should not be made with boiling water, but slightly colder. So put the kettle on now, and it should be a good temperature by the time we need the water

  2. Grind the coffee. On the KG79 grinder, there is a timer to choose the amount, I have this set to the far left (shortest). And you can adjust the grind with the knob on the side, I have this about ¾ of the way to the finest setting. Only adjust this knob whilst the grinder is running, as it has beans jammed in it when not running and will seize. The goal is to grind about 20g of coffee. When you first get the grinder you can weigh the empty coffee grinds container, run the grinder then weight it again and work out the weight of coffee and adjust the timer accordingly. Unlike espresso you don’t need to be as exact with the amount.

  3. Put a filter in the bottom of the Aeropress and put it on top of your mug. Pour some of the just boiled water in the top, to rinse through (gets rid of paper taste of filter) and warms up the mug.

  4. Chuck out the water in the mug

  5. Put the Aeropress back on top of the mug and pour in the ground coffee. You might need to tap the coffee grinds container a bit to get them all out. This is where you might make a mess.

  6. Pour in water to the top of the Aeropress, give it a stir with a spoon for a few seconds to mix the grinds all up

  7. Put the plunger in the top, just push it in a bit… by leaving the plunger in the vacuum keeps the water from all running through immediately

  8. Leave it to stand for 2-3 minutes.

  9. Push the plunger slowly down to get the coffee into the mug. Set the aeropress aside to cool, it will drop a bit of coffee out.

  10. Top it up with a bit of boiling water if needed.

  11. Enjoy your coffee

  12. Later, when the Aeropress has cooled down, unscrew the cap at the bottom and push the grinds and filter out into your food recycling bin and rinse it off ready for next use.

And for subscribers... below is a video on using an Aeropress:

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