A couple weeks ago I had lunch with my friend at a local roaster, Industry Beans. It was a hot day and we were enjoying a fifty/fifty, which is two coffees sipped side by side, one a cold drip and one a cold immersion brew. As we enjoyed our coffee we enviously drooled over their huge cold drip set up. You can check out the size of it on this Urbanlist article. My friend then told me how much we wanted one of these set-ups at home so he could have cold drip coffee at home, but he couldn’t afford it.
I, being a chemologist, just looked at the thing and thought ‘lab glassware’ and said to him I could just buy some glassware and put it together way cheaper. Boy was I wrong. I would need a 500 mL separatory funnel, a glass filter funnel and a conical flask to collect coffee in… and all that, plus postage of glassware (!) adds up to nearly the price of the fancy Japanese setup!
So what does any good lab chemist (or kitchen chemologist) do? They lab hack it (or kitchen hack it). When we needed specialist gear back in the lab and couldn’t get it, we would MacGyver something together. So following that premise, I thought about MacGyvering a cold drip set up out of things I have in my kitchen.
Equipment for home use.
So we need just three bits of equipment, a dripping device, a filtering device and a coffee receptacle. The receptacle can be anything you have lying around your kitchen. I’m using an old jar with a wide mouth. Just make sure it is large enough to hold the volume of water you will be using. The filtering device needs to hold a fair amount of coffee. I have an AeroPress at home; it is the perfect size. Finally, a dropping device, which is as simple as an old water bottle with a hole poked through the lid.
But what is so good about cold drip?
Because cold drip (and cold brew) coffee extracts the coffee at cold temperature, some of the more bitter flavoured compounds in the coffee beans do not get extracted. This imparts a sweetness of flavour on cold brewed coffee that you do not get when hot water hits the beans. Also, choosing a lighter roast, a filter roast rather than an espresso roast helps too.
How do I do it?
I’m still experimenting with coffee to water ratios. At the moment I’ve been doing 1:10 (50g of ground coffee with 500g water), but I had been doing that with a very finely ground coffee. However, I was complaining about the grind of my beans to my barista at one of my favourite cafes, Padre Coffee at Queen Victoria Market, and he was kind enough to provide me with some courser coffee, ground for a manual filter, a natural Mexico San Cristobal, and that ratio made the coffee too weak. I will try a 1:8 ratio next time. I have noticed that the coffee is less cloudy using the coarser grounds.
The other thing my coffee guy at Padre Coffee recommended is old coffee for cold drip. The beans he gave me had been roasted nearly 3 weeks ago. I’m not sure why that is… that is something for me to find out.
Cold Drip Coffee at Home
Here’s your kitchen chemology hack for cold drip coffee at home. Try it and let me know how it goes. Did you have success with a different ratio? Or a different grind? Of a particular bean origin? If we collate our results we can scientifically analyse them for the best results! Or, you know, you can just enjoy some good cold drip coffee at home.
Aeropress Cold Drip Coffee
50g coffee, ground for filter
- Place two filter papers in the filter chamber of the Aeropress. Weigh in the coffee. Place the Aeropress over a receptacle.
- Measure out the water. Pour some of it into the coffee grounds. Mix until evenly wet, then tamp down to get an even surface.
- Fold another filter paper into eighths and trim off the outside edge. Unfold and place on top of the damp coffee.
- Poke a small hole in the lid of an old water bottle. Fill the bottle with the remaining water and place upside down in the Aeropress.
- Wait a few hours over overnight for your sweet, cold coffee. Drink as is, or over ice.