Dark fluid Coffee beans

I first heard about Dark Fluid from 'The Independent Coffee Book London'. Which is a splendid guide to London's cafes, espresso bars and coffee roasters. At the UK Barista Championships they managed to secure second place with their coffee beans and also pick up awards for best cappuccino and best signature drink.

Shane and Lawrence at the Dark Fluid roastery

The whole concept for Dark Fluid came from a day of open-air roasting at Lewisham Market. The company was not started by business men, looking to capitalize on a growing market, but by a small group of coffee enthusiasts with a little ingenuity. They have a fantastic knowledge about coffee which is intrinsically linked to their great passion for what they do. As well as the a solid foundation in roasting they have a mobile coffee brewing stall, which they operate at Brockley Market every Saturday. I went down one afternoon to try this award winning coffee, which is where I met Lawrence Sinclair.

Their current roasting machine

Their first roasting machine

Before starting Dark Fluid in 2011 Lawrence work in Michelin Star kitchens in the North of England. His culinary experience seems to have given him a great understanding of the science behind roasting. He invited us down to a small garage not too far from Brockley and Lewisham in South London, which is where he roasts the beans. The first Machine that Lawrence used was a little Hottop coffee roaster with a capacity of around 300g per batch. Perhaps not ideal for a commercial operation which is why Lawrence now uses a machine that is a little bit bigger. He made his own modifications to the drum on his current roasting machine in order to achieve his desired convection and conduction and I must say that the results a spectacular!

Dark fluid supply their Espresso blend to a hand full of cafes around South London and are about to launch an on-line shop very soon. For the drip coffee on our trike they have been supplying us with single origin beans since we began. Although the single origin beans are different every time we buy them they're always of the highest quality. The espresso blend, which we don't use because we don't make espresso, also tastes great; it has a nice strong flavour like you would expect but very little bitterness and a sweet nuttiness that results in a wonderfully balanced and delicious coffee. If you are in London and in Brockley and fancy a coffee and it's Saturday then you should go and check them out at Brockley Market.

Our Carbonated beverages

We had the idea quite early on, before we purchased our coffee trike, that it would be a lot of fun to sell something that we'd made from scratch, another commodity to supplement our coffee sales. Because of our experience as cocktail bartenders we were both very comfortable making drinks. Squeezing and blending fruits and spices to make soft drinks was a quick and compelling thought but this idea didn't get truly exciting until we thought about carbonating and bottling them.

A rhubarb and star anise experiment mid-production

We started doing some experiments with different flavour combinations. Principally we attempted to make original compounds but occasionally we'd try a twist on classic recipe, like a cream soda with salted caramel, things like that.

After the initial flavour development stage in my kitchen we then advanced to batch production for sales on the trike

Larger batch production meant we needed to buy more base ingredients, a lot more! To accommodate the large amount of fruit we now had to transport from New Covent Garden Market to our work space we had to buy a little trailer that would attach to my bicycle. We found a great company called 'Chain Reaction' and they made us one of their 'Y trailers' which worked perfectly.  

One of many trips to buy fruit from the
 market using the 'Y trailer'

Pitting plums

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Juicing plums

We make the component ingredient for the drink ourselves. If one of our sparkling soft drink has plums in it then (like you can see in the pictures) we don't buy in pre-made juice. We go to the market and buy some plums, pitted them and then juice them. Similarly with any syrups or anything else. If it's in there then we've made it. This give us a nice feeling of satisfaction and a lot of control over our finish product.

Christelle labelling our bottles

The only down side of doing each stage of production ourselves is that it can be very time consuming. Luckily I have some good friends to help me out, like my flatmate Christelle, although I'm not sure how happy she is about it.

The reaction to our soft drinks on the trike as been very good. We've had a few cafe owners interested in stocking them. Because of this we are going to start production in a wholesale capacity. Currently we are looking for our large space for large production volumes.

Our coffee

We brew our coffee mainly using the Hario V60 dripper. We don't have an espresso machine, sadly no latte art and no espresso but not to worry we can, happily, do a tasty cup of coffee.

Hario V60 In all it glory.

The V60 is basically a glass cone with some spiralling ridges on the interior and a hole at the bottom. The Hario website tell me that these ridges allow for 'maximum coffee expansion'.. If they say so then it must be true but I've also heard it suspends the filter paper, leaving a gap so coffee can be extracted evenly from all over the cone, not just the bottom. The method for using this contraption is very simple, just like making an individual filter coffee; place the V60 on top of a cup, place a filter in it, place some ground coffee in that filter and pour hot water on top, very easy. 

However, when practising the olde brew coffee you need to think about your coffee extraction, which is how much coffee ends up dissolving in your hot water. There are few things that you need to know in order to achieve optimum extraction and for those curious to find out I've complied a little Blackwater guide to a lovely brew, coffee that is not tea.

Blackwater guide to lovely brew

Water

First off your water shouldn't be too soft nor too hard, a bit of a baby bears bed scenario. Now this is not a massive big deal really but if your striving for perfection then you need the perfect water. If the water is too hard then all the minerals will take over from the taste of the coffee. If it's too soft then the coffee can taste a bit flat, it needs some minerality to hang onto. Around London the water's hard so we pump it through an Everpure filter which takes out all the minerals then puts a little back in.

Temperature
As well as being the right sort of water you need to have the right temperature. We brew at between 95 and 96 degrees Celsius. Think about how easy it is to dissolve sugar in hot water compared with cold. If your water is too cold then you'll end up with a weak and under extracted coffee.

Ratio

The ratio of coffee to water is very important, incorrect ratios lead either to weak and under extracted or a bitter and over extracted coffee. The Special Coffee Association of America (SCAA) recommended 1 part coffee to 17 part water, I'm not going to argue with the SCAA. We make our coffee using 200 ml of water per cup,working to SCAA's ratio, that's 11.7647059 g of coffee per cup. we'll call it 12g. 

Grind
The grind should look like a coarse sand. The finer the grind the more surface area is exposed to the hot water resulting in more extraction. We use the Baratza Preciso which has an incredible 440 different grind setting, this allows us to be extremely precise. We tweak the grind depending on the taste, you should do the same.

Wet the filter

Any paper filter will have it's own amount of dissolvable solids; that is particles within the paper which will dissolve in water. You should always flush these particles away before you start brewing by wetting the filter with hot water, otherwise you can have a paper tasting coffee

Wetting the filter paper to get ride of paper taste.

Bloom
Discarding the paper tasting water from the cup beneath your V60 and fill your filter with ground coffee. You will now need to 'bloom' the coffee. Blooming is when you add a small amount of water to moisten the grinds. when wet the coffee releases carbon dioxide causing it to expand (bloom). why bloom? to make sure there are no dry pockets of coffee.

Turbulence
Using the Hario pouring kettle (no I don't work for Hario) we pour the rest of the hot water onto our blooming coffee. When pouring it is good practise to circle around the middle of the filter to create water turbulance which moves all the grinds around, which again makes the beautiful dream of even extraction a possible reality.

Brew time
Our brews take between 2.5 and 3 minutes. If yours races through in 1 minutes then I would suspect that your grind is too coarse and your coffee is under extracted. If it takes 10 minutes then it's probably too fine, over extracted. But the only way to find out is by taste.. unless you happen to have a refractometer kicking around, like we do, which measures dissolvable solids in liquids by the refraction of light. if you do then optimum extraction measured by the amount of dissolved solids in a liquid is 1.2 but It's always better to check by taste..

Optimum extraction,YES!

The beginnings

Left to right- Andy Mil, Joe Wood, James Hopkins, Raymond Blanc
JJ Goodman, Dave Cook and Me 

Workcycles cargo bike.

Before starting Blackwater Coffee Company, in 2012, I worked at The London Cocktail Club for JJ Goodman and James Hopkins. In 2009 James and JJ won the BBC series 'The Restaurant'. Their prize was to open a cocktail bar with Raymond Blanc, David Moore and Sarah Willingham. I was lucky enough to be part of the opening team. The bar was fantastically successful and one year later I was the General Manager of their second London Cocktail Club. I took a lot of inspiration from JJ and James; they have the compelling mix of enthusiasm and astute business acumen, qualities that I think underpin successful entrepreneurship. James and I had both worked with coffee in Melbourne, a city with an amazing cafe culture. One day we were chatting about a coffee van we'd both seen around London. I'd tried the coffee from them and it was poor but the concept, we both agreed, could be really good. I was looking to try my own project and this notion stayed with me.

At that time I had just been introduced to pour-over coffee and was very excited about the delicate flavour that could be achieved with this method. Unlike espresso, which pushes hot water through coffee grinds at high pressure, pour-over coffee gently extracts by steeping. To my mind it produces a lighter more aromatic style of coffee which, if made with care, can be sublimely good.

Our layout design for the mobile coffee trike 

Shane was working as the bar manage for the first bar JJ Goodman started, before 'The Restaurant' TV series. He was very knowledgeable about all categorise of food and drink but with a real passion for coffee. I asked him if he would like to be my business partner on a new project and he happily agreed.

I came across a company called Workcycles They made old Dutch style cargo trikes known as 'Bakfiets'. The old style trikes they made were of a sort commonly used by trades people in the early 20th century.

Workcycle HQ, Amsterdam

Shane and I both wanted our coffee venture to be as environmental friendly as possible, I think it's fairly reckless for any 21st century business not to be, and these cargo bikes looked like they could be the ideal method of transporting our mobile operation, doubling as a beautiful work station and fitting in to our environmental ideals. Together we drew up a layout plan of how potentially the trike would work and then caught a flight to Amsterdam (obviously not great for the environment but it gets you places quickly) to check out the trikes and meet the Workcycles crew. The idea seemed viable. 

Setting off from London to Harwich

Although we were working as cocktail mixologist at that time Shane and I had both worked as baristas at various stages off our drinks careers. However this had not been for a few years and we wanted our pour-over coffee to be the best pour-over coffee! Shane knew of an incredible coffee shop, called Prufrock Coffee, which offered intensive training to help others achieve their high levels of coffee excellence. Our tutor, Jeremy, was incredibly knowledgeable and helped us understand the science behind pour-over. Confident with our coffee and optimistic about our concept my Dad agreed to lend us some money and we put a down payment on the trike.

Cycling the trike on to the ferry back to England

After Ten weeks the trike was ready to be picked up. Shane and I cycle from London to Harwich where we met my Dad and then got a ferry to the Hook of Holland. From there my Dad drove and we cycled to Amsterdam. We pick up the trike and brought it back on the ferry to England. Upon our return we towed the trike to Lincolnshire, on a borrowed trailer, to my brothers father in-law's house and started mounting and fitting our coffee making equipment on to the trike. After a week of sanding, staining and fitting the trike was ready.

The finished Trike

Trading

By the end of June we had started trading..