Hi,

after quite a while of toying around with different parts, tinkering a bit, much tasting and some more toying around i've finally finished my current coffee project: The ColdDripper-Guy, CDG, my attempt at cold extracting coffee in a hand dripper, the Hario V60.

I've built two versions, one for the small, one for the large V60. The dripping mechanism is realized using a small plastic spigot as found in home/hobby fish tank equipment shops. It allows a relatively fine regulation of dripping speed with a range from a full flowing stream to a single drop all 20 seconds. Thats enough for our usecase here. This spigot is then affixed to a former liquor bottle which i happened to have at hands, looks good~ish and has a relatively large cork made of plastic - this makes it ideal for my use. I've drilled two holes into the cork, one gets a long hose running all the way up inside the bottle, the other gets a short hose running outwards. The outwards hose is connected to the spigot, after the spigot comes another long hose which ends directly above the filter. The whole construction with the inside tube is to let some air in so no underpressure will buildup inside the bottle preventing further dripping through the spigot. The advantage of the inside hose over a hole in the bottom (reversed: top) of the bottle is - putting the need of a glass drill aside - that you can fill the bottle upright, insert the plug with the hose, then turn it upside down over the sink letting the only few drops in the inside hose drain, then simply put it on the CDG.

In the past i had tried medical drips i got by asking a friend who works in a hospital nicely ... they worked even better in terms of regulation, but a) i suspect its not really necessary here, and b) the filters they have are super fine ... which is good, considering their original use. For us here who fill tap water in those drips its bad, because those super fine filters clog super fast ... so i ruled this one out.

Anyways, long talk short, here are the pics (first two pics were my beta ;P):
(OH GAWDS! Why's the image upload function here so sh****? And why are offsite images forbidden? Makes no sense to me ...)
Gallery / Index: http://pics.kanojo.de/ColdDripper-Guy/
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So after the obligatory pix, i think i should mention the most important thing here: Wood Texture... uh wait, i think i ought to write about the taste ;P. I use around 20-25grams of very very coarsely ground (coarser than for handfilter and coarser than for frenchpress) coffee which i prewet a little so all the grounds are evenly wet and there are no dry nests. After that i set the drip so i end somewhere between 3 and 4 hours for a total of 400ml (with the small Hario!). I of course also rinse the filter using (hot) water beforehand. I also cut a small circle out of a filter and put that on top of the coffee grounds, to distribute the water coming down in drops over all of the grounds...

The taste is quite astonishing to those who haven't tried cold extracted coffee yet. There is a wider variety of aromas than one might think, the biggest difference to hot extracted coffee is probably in the "deeps", the woody, earthy, chocolate-sweety types of aroma. Those are a bit muted, but still there. The biggest suprise is the floral notes really. We're mostly used to very "floral" and "refreshing" coffees to have problems with acidity. With a very flowery, maybe citrusy coffee in espresso we always fight the acidity down to get a enjoyable result. Here you get the balance seemingly for free! Everything's there, and i've never ever had a problem with astringency or acidity, not even the slightest! Putting a very floral-biased coffee in you get all the variety of aromas out you ever wanted to taste, without the slightest hint of discomfort. Wow, just WOW!

The Wood is by the way simple birch multixplex that i've got from the waste parts of my local diy market ... thats why it's not quite so nice, with that knotholes and all that stuff. After cutting it on my tablesaw i've joined it using lamello joints to ensure the necessary sturdiness with such a length. After sanding it 80,120,240 with intermediate watering, i've started to oil using linseed oil 1:1 with oil of turpentine (wood turpentine?) three times, each one a little less diluted. I've also sanded it 240-350 in between with some oil. The texture really nails it, and it should be humidity resistant enough for this job!

Anyways, if you have any suggestions, criticism or comments, i'll look forward to it!

Best Regards
- NebuK

Looks like a nice setup, not too big and I like the wood.

Have you tried with cloth filters or just paper? Some claim a big difference with the cloth filters with cold process coffee.

Really noone to comment it?

Split follow-on discussion to Uploading multiple images is tedious.

This is pretty good!, one of the best home-made cold drip coffee makers i've seen.

I love this method, and it yields a much superior taste than cold immersion brewing (Toddy Style), but the prices are incredibly expensive for such simple devices (200$-600$ for cold water dripping over a bed of coffee), so making a home-made version has always seemed like the only option for me...

Thanks for the tips on using aquarium tubing valves for controlling the drips, i would have never thought about it, i think i'm going to give it a try.

I'm still unsure about how your second tubing going all the way up the bottle works, i know you put it there to avoid the dripping to stop midway in the brewing process due to lack of air, but if this hose is connected to the second hole you drilled on the plastic cork, how do you manage to keep it from leaking down? i think i'm missing something there, i looked at all your pictures but still can't really tell what's going on in there.. maybe you should make a video, and show the brewing process as well.

By the way, how did you decide on the Hario V60, i don't think the conical shape helps when brewing this way, do you put a paper filter on top of the coffee? how do you manage to evenly saturate all the coffee bed? Wouldn't an Aeropress be a much better option? you could use a paper (or even metal, such as Able Brewing ones) filter in the lower part, put the coffee, then put another aeropress paper filter on top to help distribute the drips evenly over the bed of coffee.

Hey,

first about the hario: I just happened to have it, and i don't have a aeropress. I'm also not sure the aeropress would work - doesn't the bottom (rigid) filter need quite some pressure to let fluid through? As said, never held one in my hands ;P. I don't think the shape of the hario helps paticularly, but ... its a holder and i have it, so i used it ;P.

Yes, i do cut out a circular piece of the hario filter papers and put it on top of the coffee. I try to press it on the (already prewettet) grounds a bit and try to level it. I think the resulting extraction is even enough. When looking at the grounds there are no depressions or nothing that could look like channels or "water holes". Also ive tried shoving small portions in different cups, infusing them with warm water and tasting them - if the extraction was uneven, some cups would've tasted differently. But all tasted the same (and quite horrible, i must say! ), so its probably ok.

The second hose works like this:

The two holes in the cork are not connected. One hole is open towards the inside of the bottle, thus creating a drain at the lowest point. This one is connected to the aquarium valve.

The other hole is open towards the outside of the bottle, and inside theres a hose connected going all the way up inside the bottle. When you fill up the bottle with water, insert the cork (with the "inside" hose) into the bottle and fasten it the inside hose is at the very bottom of the bottle (later on the dripper when the bottle's inverted, its the top). You then turn around the bottle over a sink and a small amount of water will leak out of the "air vent"-hole - this then creates a small bubble of air at the top of the bottle, the air-vent-hose resides in this bubble, and that's why no further water drains out, but the hose is connected to the inside of the bottle allowing air in and acting as a (under)pressure relieve, making the dripping possible.

Hope i could help ;p. Do not refrain from asking further.

Regards
- Dario

I got it! i was toying around with the idea yesterday and finally figured it out, it's pretty clever, and works amazingly well, although i think a rigid glass or plastic tube would look better than the the little hose.

On the Aeropress...by all means do get one, not only you can make great coffee with it in lots of different ways, i've tried it for cold drip brewing, and no, you don't need to exert pressure for the coffee to drip through the filter, i've even tried it with the metal ones and works perfectly, not sure if it would be an improvement over your V60 set up, but it probably should, all commercial cold dripping devices use a cylindrical container for the coffee, i'm sure there's some thought into that. I've seen some people use the upper chamber of syphon brewers for cold dripping and it also seems to work nicely, i don't have one tough.

Next step is to make a wood stand, i already got the tubing, the aquarium valve and a cool looking 1000ml Evian glass bottle shaped like a teardrop, i found that using a plastic cork is not really necessary, i drilled the two holes through a normal water bottle plastic cap and fitted both the valve and the long hose and got no dripping whatsoever through the sides of the holes. The aquarium valve i found is shaped different than yours, mine allows it to plug it directly to the bottle cap (or cork) and it drips downwards, with the valve control sideways. If i ever finish it i'll take some pictures. Thanks a lot.