Thing of the week - Jamaica Blue Mountain Coffee.

Hey everybody, what is going on?
I'm Roger In Technology and this week I'd like to give an honourable mention to Wallenford Estate coffee.

Coffee is a relatively modern tradition, dating back up to a thousand years by some stories but only becoming a global phenomenon in the last five hundred years. Over the centuries the coffee industry spread to Europe and the Americas and has grown stronger, spreading globally.

The technology behind coffee remains largely unchanged although products, practices and tolerances have improved to keep up the demand for quantity and quality. From the simplest stove-top pot to the largest, steaming, frothing, barista machines the sale and consumption of coffee has become an ubiquitous part of modern technological development, driving artists, philosophers, and programmers well through the night with its delicious aroma, taste, and chemical stimulation.

While apparently it's medically possible for a human being to go without coffee for long periods of time, it's not an experiment I could contemplate running. In the twenty-first century we drink well over two billion cups of coffee a day.  I'm doing my part, are you?

The Wallenford Estate review this week is based of off two cups of Wallenford long black, both purchased and consumed at a coffee shop local to me.

The long black was served as a 12oz cup, which is a good size for a double shot coffee. I used to enjoy it a little stronger but this is a good way to get the flavour. I take my coffee straight black, and while I never add sugar or syrup on the first cupping I will often pick something that goes well if it's a drink I will return to time and again.

The initial hit of the Wallenford was a little more acidic than I'd expected, not quite citrusy but certainly accompanied by some high notes. Drinking was smooth and easy and the body of flavour comes from its mid-tones, I found it very drinkable and the cup disappeared surprisingly quickly.

The overall palette is very mid-balanced, medium bodied coffee with few high notes and no great earthy flavours to drown out its almost buttery flavour.  If found it missing the sweet fruity, cherry, flavours I was hoping for and that part of the spectrum was surprisingly absent but its uncomplicated mid flavours were pleasant.

I will say there was a slight coffee-shop finish.  Filters in coffee shops often leave too much grit in the drink which does contribute toward a darker, more bitter finish to the cup than is otherwise fair. But even considering that the finish was fast and clean, and any lingering taste wasn't unpleasant.

My other critique would be the paler-than-expected crema typical of an over extraction. I'm not going to put too much into the colour of the crema, but darker is better and I find over extractions a little sharp and combined with the bitter body I think the preparation let the coffee down. Both of these are preparation artefacts that wouldn't be present if you made it at home and not inherent to the bean. Despite these points it was a very fast drinking cup and any bitterness was brief and mild.

I enjoyed shortbread with my second cup, which I thought would bring out the buttery sweetness and create a simple combo but I found the flavours clashed too much and didn't play to each other. Not to say it wasn't enjoyable, just that it was far from the perfect combo I'd expected. The Wallenford is missing a nutty body, so think hazelnut balocco or hazel syrup if thats your style. I did leave thinking that a dark chocolate brazil would go well, but didn't have the chance to try the combination. To the coffee shops credit the cup was the correct radius for a stroopwaffle, and although I didn't indulge I'm sure every long black works well with the dutch delight.

I didn't manage to make my own Wallenford yet, and I think that the fine paper filter of an Aeropress would significantly improve its finish, and bolster its strength without sacrificing its smooth body. I'm going to guess that it's best enjoyed at an americano strength where it's uncomplicated butter feel will linger and be enjoyed.

Overall the Wallenford Blue Jamaica was a good cupping, and I enjoyed the drink despite the number of flaws I've presented here. I've tried to be fair and balanced, and while I have a personal preference for some of the light, cherry and fruity coffees of Africa the Wallenford was a good drink in its own right.  I wasn't blown away but I did enjoy it.

Thats all for this week. If you've got a favorite coffee let me know and I'll try it as soon as I can. If you have any tips or suggestions for a future Thing of the Week then I'd love to hear from you.

Thing of the week - Casting Tools.

Hey everybody what is going on?
I'm Roger in Technology and this is a quick project update on the Foundry.

Since I want to cast some bronze, I've got to make some tools on a budget. The bucket foundry cost next to nothing, is lightweight, completely portable, clean-burning and far exceeds a thousand degrees. So far my efforts have been met with nothing but success I'm staring down the barrel of two significant purchases.

Metal Ingots
The first is the metal stock. Copper and Tin ingots can be bought, and are going to cost around £30 per kilo including postage, I think tin is more than that. I'll shop around and get slightly cheaper but that's the ballpark. I'm going to need one tin ingot, and I guess that means ten copper ones but I'm reluctant to make eleven kilos of bronze. It feels like a lot for the small projects I've got in mind.
Buying copper in smaller (than 10kg) quantities is more expensive, and the cheapest option is about ten kilos of copper and one of tin - but that's around a £300 materials cost. I guess I could soak up the cost but its a huge outlay this early on.

Recycling aluminium drinks cans is a good idea. It'll continue the thrift-shop philosophy I've adopted so far and allow me to make a casting flask, practice to process, learn how to make casting sand and generally run the whole process start to finish before I start ruining home-made bronze.

Anvil
Astute observers will notice that I haven't talked much about anvils. Until I have a forgehouse built, there is nowhere to put an anvil but I'm not going to be able to work steel, or even work harden bronze, without one.  The anvil is a versatile tool that so much smithing relies on.

An affordable cast iron anvil just isn't worth owning, you can buy cast anvil on amazon for fifty quid but they look terrible and frankly thats a lot of money for something thats just going to be used as a doorstop.
I've found a wide faced farriers anvil for £450 that looks perfect. But this alone costs more than I want to spend and it'd be a shame to come this far only to divert all my budget into a block of steel - no matter how fancy.
To this end I've managed to get a sledge hammer, its light - only 7lb - but once set into a block it'll give me a hard enough surface to make a few small tools and to work harden bronze on. I could buy a 14lb hammer very cheaply, but the 7lb head is light enough that I may actually use it later on so there should be no waste.
I'm going to back this up with a granite block from the garden centre. Its not too costly and will be equal or better than what was available to my bronze age predecessor. It'll probably be fine for work hardening bronze on, and in combination with the sledge head I think I'll do fine.

Crucible Tongs and other casting tools.
I've bought screws and some timber to make a flask, a couple of clamps and some more sandpaper. The costs there are low but mounting up and I do want to keep an eye on the spend. My makeshift hammer-anvil will be sufficient to make some tongs, and with those I'll be able to make some crucible tongs, a ram, rap and all some other trinkets for casting.  The overall cost here is very little. I could use scrap steel, and I've got a couple of mild steel bars including my thermometer that I could turn into tongs.

Lastly, I've spent some time carving a couple of patterns to cast. This was done with some timber and a stanley knife, and then 60 grit paper.  I can see myself making a steel whittling knife as a very early project once I start working steel because this was a lot of fun.
The most interesting of these is a pattern for a bronze dagger. Its in the style of a bronze age Wilberton, just a smaller blade - probably about ten inch. This was cut from cheap timber and is about the shape I wanted but I don't think I've left enough excess for shrinkage and finishing so the end product might be a bit small.
When I scale up, I'll probably try a full size Wilberton, or a Ewart Park style sword which I can cast and finish in bronze.

I've started carving a wooden ram and rap, and I'll be collecting aluminium this week.  I also need to carve some ingot casts for excess material but after that I'm ready to run through the whole process with my wilberton style dagger in aluminium.

That's a roundup of the project status, and my thoughts on tools and materials. I'm also arranging to borrow a video camera so should be able to start videoing the process from here on in.

If you have any questions on metal work, wood carving, or smithing then leave a comment. I'm not staying a hundred percent authentic to traditional methods, but everything I'm doing is with simple tools available to the everyman.

Thing of the week - Foundry part 2

Hey everybody, what is going on?

I'm Roger in Technology and welcome to Thing of the Week for the twelfth of May 2015

Mankinds mastery of fire was once a turning point of civilisation. Controlling and maintaining fire led us from the stone age to the bronze age which gave us access to all manner of new tools, toys and technology. Thousands of years later, we are able to casually and recreationally create a foundry from household materials, standing on the shoulders of giants that have forged a path before us.

This week we'll be talking about my new foundry, started in a previous article here:

Thing of the Week - Foundry Part 1

I took the time to test my foundry fire, using a piece of 3/8 inch roundbar as a thermometer and the results were as good as I could have hoped. And possibly better.

There are a few differences between this bucket foundry and the original build. I wasn't happy with the shallow depth of the first build so in the intervening week I poured a second layer to nearly fill the bucket with refractory concrete and get a good seven or eight inch depth to snugly fit my graphite crucible. For safety reasons this meant the foundry was out of action for a weekend while it cured, but it'll cleanly fit my 155mm crucible.

The mix was the same 50/50 sand and plaster of paris and poured in the top to fill out the height. The sand was less compact than the first batch so the colour is a fraction paler but it's the same colour once blackened with fire and colour coordination wasn't on the feature set. 

Air Blast

The bucket forge here is powered by a cheap hairdrier from the supermarket it's on a low setting, and a good six inches from the air intake to keep it cool. There is no ducting - the picture was taken live with the setup. With some ducting I could blast the air right into the fuel and get a much better burn so I think the airflow could be improved.

The reliance on electricity isn't a huge problem but one I'm going to move away from.  I'm estimating around 30-40 cubic feet per minute and fifty at the tops.  For under ten English pounds I can buy an eighty cfm brushless 12v dc fan and power it from a peltier thermoelectric generator using the heat of the fire to fan its own flames. I'm also considering steam power, which would be a nice metalwork project.

Sparky

Astute observers will notice there are a lot of sparks in the picture. I chose this picture simply because sparks look cool and I'm embarrassed to admit it - but they are just from some kindling I added. Most of the fuel was clean, which overall is a requirement for a hot burn. The fuel here was cheap lump-wood charcoal from a supermarket and it's quite good enough for a home foundry. It was a clean, hot, almost smokeless burn.

Off camera, two fourteen litre buckets of water stood by quench any cinders that ignited the dry recently cut grass and woodchips left from the afternoons whittling. Safety first people.

Temperatures reached

This 3/8 inch round-bar reached a good yellow colour and in the region of 1100 to 1200 degrees C, that's something like 2000 to 2100 degrees F and well hot enough for working with. From its softness I've no doubt it was that hot. 

My goal was to reach a steady nine-fifty degrees so that I could confidently melt bronze and frankly having exceeded that with a margin to spare this yellow steel signifies a reason to celebrate.

In fact I was amazed how quickly the fire beat the nine-fifty mark without the lid on or a proper air supply. It's already hot enough to melt bronze, and there are several improvements to be made.

Refractory lining

By the time this picture was taken, the exterior of the bucket was warming up but still cool enough to hold your hand against - maybe 50 Celsius rising to around 70 near the base compared to bringing steel round-bar up to a thousand degrees.  The base is slightly thinner than the walls because I wanted as much crucible height as I could get and it's the weakpoint in the design. 

The exterior wall eventually got hot - maybe even above a hundred - and and extended forging could be a problem.  As a foundry for small bronze, brass or aluminium projects then the bucket wouldn't get overly hot but it will really heat up if I run it as a forge for a few hours. A sturdy base of commercial firebricks - then it'll be fine. I don't think the bucket has any risk of failing.

Closing thoughts

You can do an awful lot with very little. Plaster of paris, sand, and a steel bucket cost next to nothing in this day and age.  I bought a value hairdryer from the supermarket and used some cheap lumpwood charcoal to get these results in my garden.

Armed with a modern understanding of metallurgy that outstrips my bronze age counterpart, I should be able to produce results worthy of a traditional redsmith. The first world information age has provided means and materials that would have astounded and amazed bronze age Europe.

I started this journey knowing very little about the technological landscape from three thousand years ago and I'm already impressed with what they achieved, and they did it without being able to drive to the retail park and buy sand or order buckets online.

Thing of the Week - Scones

Hey everybody what is going on?
I'm Roger in Technology and welcome to Thing of the Week for the Seventh of May 2015.

The discovery of fire brought mankind heat, protection and cooking but arguably it was the invention and refinement of the oven as a cooking space that revolutionised our relationship with fire.  Early ovens date back thirty thousand years and we've come a long way from the primitive pits used to cook mammoth. As far as I can tell, ever since then mankind has been striving to develop the ideal oven that cooks evenly to bake the perfect scone.

Ancient civilisations developed stone, brick, and clay ovens to radiate heat evenly, some employed smoke dome and chimney arrangements to use the heat of the smoke too. There are so many mechanisms and designs of oven over the centuries. From insulating clay ovens and metal agas that employed the huge heat capacity of their bodies, modern gas ovens allowed for precise fuel consumption to regulate temperature. But its the electric age that raised the bar by adding thermometer control. Thus the electric oven has taken its place as the final step in this long journey our civilisation has taken to reach peak scone.

The humble scone has existed in one form or another for centuries, and uses the most basic of cheap ingredients. Delicious sweet or savoury, they have become synonymous with cheese, cream teas or strawberries and bubbly. Whether you like butter, honey or fruit, the scone has a lot to offer as part of a balanced diet.

Top scones continue this tradition of self raising flour, butter, sugar and milk.  Often egg is employed to richen the mix, or an egg glaze is used for the same reason.  But do not trust a scone with egg, its a distraction tactic that just isn't needed on a good bake - the advice here is stick with the classic ingredients and use additions that theme and personalise your scone.

Fruit can be used, and often is. Sultanas are a classic for a reason, and they can be added to the mix or studded before baking. A little grated lemon zest offsets sultanas and lightens up the aroma and palate here.
Roast strawberries are a delicious addition too, although extra preparation is needed, and the addition of summer fruits give a fresh seasonal twist. Later in the year, orange and cinnamon can bring a delicious scone to life too.

Sifted flour should be mixed with sugar in a bowl. Typically only a tiny amount of sugar is used, even for sweet scones which can get their natural sweetness from fruit. Rub the butter in until you have breadcrumbs and slowly add the butter until you have the dough. Flatten it out and stamp some scones for baking at 220 degrees for fifteen minutes or until golden brown.
You can find details about proportions and recipes online, and should be able to find something that fits your tastes. I know less about baking than I do about history but even I can tell this recipe that has stood the test of time will be with us for centuries to come.

I enjoyed these scones warm with honey, which I can heartily recommend, as the subtle sweetness blends with the enticing aroma to produce a breathtaking masterpiece.  I hope you are inspired to get back to the simple roots of baking and experiment with the humble scone, as relevant in the 21st century as it was a thousand years ago.

Knife of the week

Hi guys and welcome to Roger In Technology.

This week I've picked a bit of steel to talk about. The invention of steel represented a cornerstone in technology for mankind, allowing tools, machines and weapons to be built to a higher standard and precision than ever before.

From blister steel, through crucible steel to the wide ranges of air, water and oil hardening steels we have today the world has been taken on a one way technological journey. Steel revolutionised all aspects of technology, and new technologies were invented to refine steelmaking.

This is a Gurka Kukri style knife dating to the mid twentieth Century. It's a versatile tool and deadly weapon with a proud military history from one of the most famed and feared military units in the world. 

It's about 34cm and has quite a weight to it because of the broad belly and the width of the spine. In fact this small steel blade weighs easily as much as some steel swords, and is as heavy as a generation of bronze age swords.

Pictured here is the "before" from a restoration work I'm doing. The blade itself has clearly suffered a lot in its life. The blade is dull, and while somebody has attempted to sharpen it they just didn't have the right tools. I'm going to grind a new edge on it and then clean it up with about a 1200 grit and hone the blade.

Kukris are traditionally made from leaf spring steel, which was readily available from scrap vehicles so we can take our best guess on the properties of the steel but to be honest the exact metallurgy isn't too important for the restore work I'm doing.

The blade is showing no scaling or flaking that would be evidence of heat damage, so I'm going to assume the temper is good and we don't have to heat treat it.  Heat treating a blade like this was a daunting task that I wouldn't look forward to, and I was somewhat relieved to see no evidence of overheating on the steel.

In Nepal, there are guys that quench the cutting edge with boiling water and allow the spine to carry its heat and temper the blade. I've got no desire to water quench this mystery steel as there is a good chance I'd crack it and ruin the piece. Actually, I've got no desire to heat-treat this at all, as I'd have to remove the handle and then I'm making a lot of work for myself.

There are some spots where water has go to it, but they appear to be surface marks and will polish right out with some high grit paper. The blade is fullered, which I didn't expect from a Kukri blade where I wouldn't have thought weight reduction was a consideration, but I'll admit to not knowing anything about this type of blade so it might not be that unusual.

Other than that, the blade shape is a little uneven and there is evidence that part it has been ground down. I'll try and get a nice even shape although that will mean a little more materials reduction than would be needed to just sharpen an edge and this brings me back to the temper. If its had a differential temper then the edge will be harder than the spine and I don't want to cut into the steel too much but it looks like I've got no choice.  There is also no point second guessing the properties of a mystery steel. I'll learn a little more by working the metal but for the most part it is what it is.

The handle is maybe a little long for a Kukri, but apparently this isn't unusual for service issue blades, and it appears to be a partial tang which again is traditional.  I first thought it was an integral bolster that had taken some damage but its clearly a second block and this is where the craftsmanship lets the blade down and seriously questions the authenticity of the piece.

I don't like the workmanship on the bolster, I don't like much like the decorative/mosaic pins on the handle either. They look out of place and more what I'd expect from a replica sold to tourists than a functional tool. There is an ugly boss on the pommel too, that can't be seen in this picture, but it doesn't scream quality. The chakmak is missing but the karda is a tiny thing that looks like its been stamped out of a sheet. No attention to detail and no craftsmanship on this which again is probably a bad sign.

Finally in my appraisal of the knife my mind keeps coming back to the uneven blade. Either its been used to hit rocks and somebody has ground those nicks out, or the steel is so soft it picked them up from normal use - so it'll be no good for a knife.  Since I'm already pretty certain it's not an authentic blade, I'm worried the quality of the steel is poor too.

My next step is to grind a new edge on it and sharpen it up. I'll use it to process firewood and see how well it holds an edge. If it survives some pretty rough treatment then I'll clean it up and get a dab of oil on it and it can be used as a camping and woods knife, or out in the garden to clear the brush and weeds.
If the blade goes dull quickly then it'll have more value polished up and looking pretty than cutting anything so I'll get it semi sharp and then polish the hell out of it. I can either mount it on something or sell it on to somebody who cares more about aesthetics than practicality.