That's a great idea! I feel a project coming on... ;-)
Where did you get the dripper?
Hi all, I thought I'd share my latest... I built a bit of a prototype cold-drip tower out of some scrap jarrah I had laying around. I must admit, it's not finished yet, but I became impatient and just had to try it out!
It has three shelves, one for a feed bottle on top, one in the middle for the grinds holder, and one for the jug to catch the brew.
Top shelf consists of soft drink bottle with the bottom cut off, a 60 cent adjustable irrigation dripper tapped in to the lid and adjusted to approx 40 drips / min.
Middle shelf I've used my Aeropress brew chamber, with a metal S-filter. Grinds are added, gently tamped and some cut-down aeropress paper filters placed on top of the bed.
Bottom shelf, my Hario range server to catch the brew.
My recipe today:
58gm of Indo Wahana Natural, ground coarsely, very gently tamped, two paper filters on top so the drips don't cause an un-even extraction
600gm cold H2O in the soft drink bottle
100gm ICE blocks in the soft drink bottle
Time is approx 7 hours until completed.
Brew is then poured in to a storage bottle and kept in the fridge (can be kept for a couple of weeks, cold)
Serve straight on ice, or on ice with some sparkling water, or even with a dash of milk or condensed milk.
This is only the second brew I've done on it. Yesterday I did a Kenya Mihuti and it was very nice straight on ice, great aroma, lovely flavour and very little acidity.
I'm hoping this Wahana brew really slaps me in the face it should be interesting!
One day I'll maybe construct a more impressive tower
That's a great idea! I feel a project coming on... ;-)
Where did you get the dripper?
Bunnings (hardware store) it's an irrigation dripper
That looks cool (pardon the pun )
How much coffee do you end up with? Presume quite a bit gets left in the middle chamber?
Just a fraction over 600ml
Nice rig, well done.
58g is an odd "internet figure" and I suspect you don't have enough coffee in there, for cold drip think more like ristretto ratios. Would you pull 200ml of water through a double basket? If you did what happens after the first 40ml?
Some tips I've learnt during the last 800 litres of cold drip and 100kg odd of coffee...
40 drips a minute is about the right drip rate. Obviously it will depend on the size of the drips but for my setup 30 is too slow and 60 too high.
In the big commercial Yama cold drip I'll run 450g of coffee to 4 litres of water.
You can dilute later (as you mentioned) with cold or hot liquids.
Ice is optional. It makes very little difference to the end result unless your water temperature is above 50C. Room temperature water is fine.
You also mentioned that you "ground coarsely", I've found far better results with a filter grind, just off espresso and similar to what you would run in the Aeropress. More surface area on the grinds is very important in cold drip.
Skip the light tamp, it serves no real purpose on a deep bed of coffee as it will compact the top, not the bottom. Instead try using a more consistant tap,tap method on the bench, this will remove the gaps through the whole "puck". You can then adjust your grind depth with more accuracy.
Play around with your ratios and grind depth and you should be able to produce a cold drip brew with plenty of body and a higher concentration (which will allow more creative drinks to be made).
Enjoy the journey!
Andy, thanks heaps for the tips, after my second brew I can certainly say I need more grinds, and a finer grind would probably work better also
I just sampled my latest wahana brew and it's lovely, a real "bomb" but not as "concentrated" as I expected. I should probably work on about 120gm for 700gm water.
Cheers for the tips! all good fun
May I ask what is the yellow thing on the top layer that is holding the bottle and the dripper?
It's on again, and with Andy's recommendations on board (like double the coffee grinds)..
It's been on for 4hrs so far (pic taken earlier in the brew as you can see).. It's almost finished actually.
This time, it's Ethiopian Yirgacheffe Chelba natural
looking forward to it! hot week this week!
brew is done, I must have had the drip up faster than I thought because it finished in 4.5hrs
i've served it up on ice topped up with some sparkling water. It's nice! Sweet, fruity. Pretty much what you'd expect from a Yirg (except the sweetness). Very pleasant to drink. I like it. I've bottled about 600ml in the fridge for this week (hot).
If you have some loose leaf tea to play with, try brewing a cold brew with it! It is phenomenal
That sounds awesome!
I'm excited! Almost completed my rig today too! Thanks for the tips on how to build this. What I found tricky was doing the dripper. Had to use plumbing tape and PVC tape to make sure it was sealed. Also had to file down the sides of the dripper a bit too. Will post photos when done
Nice one! I just drilled a hole in the cap and pushed the dripper in. Doesn't leak. Lucky I spose
I see you fit the dripper in reverse/backwards to what I did! Does it work ok?
I use a metal aeropress filter (s-filter) in the bottom) and two paper filters cut down on top of the bed of coffee. (you really really need filter papers on top of the bed so you get an even extraction. A single paper filter would work in the aeropress cap if that is all you have
Last edited by JamesM; 4th February 2013 at 04:35 PM. Reason: add video
Ah... Ya it was tricky to fit the dripper on. So far so good. I only used one paper at the top. Will try 2 next time. I have the metal filter. But decided to go for paper today. Getting the misus to cut out a cloth set (top and bottom) using the beanbay bag :P
My wife actually had a weird but valid question about cold drip as I was doing this. "Didn't you say that ground coffee goes stale in minutes?" -.0" I was like "yeah... But... Em..."
hah, brilliant! tell her the damp top keeps the good stuff inside
Mate, you could be famous! Like Corretto roasting, this idea could have a name as well... The JamesM Cold Drip Rig... or something
hah, flattering, but it's not my idea, there are other folk who have made their own drip towers!
I don't get it... After coarsening the grind and increasing my flow rate, I believe a little faster that 40/min. I still get a drip rate of 9-10hrs are my markings on the Macap wrong :S
Even so, the 10+ hour first drip I did tested really good though! A lot smoother than cold press for sure! So I wonder of I got it down to 6-7hrs what different would it make? Brighter?
Normal drip filter grind (I think...)
40+/min drip rate...
On my last batch I did 100gm grinds and the chamber started overflowing with water. I had to pull the drip off and wait for it to settle before putting it back on, then it was fine..
Your recipe seems ok!
Interesting... How did it overflow? Too fast a drip rate?
Same rate but somehow choked up in the grinds and started to fill on top with water. Once I let it settle and put the Dripper back on it was fine
I was at a coffee roaster in a small NSW country town and they had a setup almost exactly like this. First sip was very bright, second sip good body and there was a bit of earthiness to the dregs. Not bad overall!
IMG_2197.jpgafter you showed us your rig james i've been itching to try it out myself!
just got a irrigation rig from bunnings today and trialled fitting it into a bottle cap - the irrigation rig seems different to the ones you have and a little more similar to what we see on commercial cold drips with an adjustable tap at the side! now to find a stand to fit it all into!
brokenvase, is your drip rate slowing towards the end of the extraction? could be that the decrease in water mass above the dripper is slowing your water let down rate and slowing the brew?
I just ran off another batch, this time Yirg Gelena Abaya natural. Drinking it now with some sparkling water and ice, it's nice
Yes, towards the end I does slow down. But I didn't bother to adjust it. 9-10hrs is fine as long as it produces a good cup. my mates didn't really like the light roast though... I'm going to try a medium roast Kenya AA tonight
Bingo!my mates didn't really like the light roast though... I'm going to try a medium roast
I think light roasts requirements are a bit of a Furphy in many different brewing processes.
The gotcha with most light roasts is it will produce a lemongrass tea range of flavours which is interesting, unique, different and not much like coffee. They have their place but I'm sure most of your mates that didnt like the light roast will love a cold drip at a more "normal" roast depth.
Blind tastings at the Snobbery have shown most people who tried cold drip (as an iced coffee with milk for the latte drinkers) liked the espresso roast ranges best. Of course, feel free to experiment with your roast depths but don't get sucked into the hype of it has to be sour if it's not espresso.
If you have the right balance of sugars, acids, body and brightness then most brew methods will shine.
"Well roasted coffee is coffee roasted well."
Great advice, worth experimenting. My brew today was I spose a medium roast. I went about 1min further past the end of first crack when I roasted it.
Turned out great
Awesome job JamesM!
At work we are rotating our single origins coffees that are roasted at the lighter end for espresso and getting very good results in the cold drip. imho darker espresso roasts are fairly uninteresting. Cold drip tends to mute acidity as it is.
Inspired by this thread. I usually just cold steep, sieve and run through the AP with paper filter for a cleaner cup. However after trying a few retail cold drips over the summer and seeing this thread I am inclined to try for myself, hoping for a crisper / cleaner cup.
Does not get much simpler than this.
40g medium grind, Rwanda Ruhuha, this was rich and smooth choc with very low acidity as espresso this morning, so im thinking it will be ultra smooth through the dripper.
about 42 drips / min
2 X paper filter on top
S filter below
Thanks for the thread, pictures and videos really help to spark ideas. Its was so simple, 2.5hrs in and its ticking away nicely.
So much easier and less mess than steeping. If it tastes better even more of a bonus.
Although to compare fairly i would have do a drip brew using the Porlex, this is my maiden manual brew on the K3P, the medium grinds looked heaps more consistent than the porlex.
Gave this a go today (pretty much Steve's model). Although my initial attempt to get the irrigation dripper into the bottle lid resulted in way too fast a drip (water must be escaping around the 'spike'), the resulting drink was fantastic on ice. This was a Huehuetango at CS8-9. Definitely going to master this.
Second time i heated the spike on my pocket knife and only made a very small pilot hole. Then kept twisting / pushing the dripper in that little hole unitl it got all the way through, 2 runs and have not had any leaks.
I ended up starting at 48drips / min the second time to allow for the big slow down on the small volume of water.
Still the end result is very very smooth, very clean, much more so than cold immersion brewing.
Think i might have to work on a slightly larger scale model over the cooler months.
Cheers Steve. I made my pilot hole with a bullet head nail....not sure why I thought that was a good idea.
This reminded me to post some photos of my version.
The frame is 1" ali tube, the bottle brackets are 90mm poly pipe and some double sided velcro, the dripper is a brass valve from the junk box and the filter is the spare screen from my Expobar held in the end of the bottle with an old group seal.
Nice gazza, that's got mad scientist / coffee nut written all over it.
Do you guys get the problem of the flow slowing down over time due less pressure with reduced volume of the water? I find that I have adjust the flow a few times over the entire process...
Wonder what cold drip would be like through an espresso machine?
Ice water in the tank, unhook the boiler elements, turn the OPV down to low pressure and there you go...
Youd probably have trouble slowing the flow down to a drip
I dunno; I've had a few espressos that've done it just fine :P