Wednesday, July 18, 2012

Coffee in Hong Kong - Knockbox hand-drip class

Last weekend, I went to Knockbox Coffee Company, one of the newer third-wave coffee shops in Hong Kong for their hand-drip (aka pour-over) workshop. You may remember that I went to another newish coffee shop, Rabbithole, to attend their coffee class not too long ago too. The Rabbithole class I attended was more of an overview of methods (they do a hand-drip class too), and I started to get curious about the different philosophies and theories baristas had about making coffee. (Plus, there was a lot of feedback and debate, on that blog post and off, about the different methods and the rationale behind them).

Coffee is a huge, huge world of which I can't even say I've scratched the surface. I drink it, religiously, or even medically (I'm peversely proud of telling people I have a medically-confirmed addiciton to caffeine), and I have my preferences, thanks to the vast and generally exceptional range of coffees in Melbourne, but do I know much about it? Not really.

I explained earlier that hand-drip has become one of my methods of choice at home, so I was keen to learn some proper technique, or at least, how the pros do it, so when I saw the workshop advertised on the Knockbox Facebook Page I leaped at the opportunity.

Forgive me if I get any of the details wrong, I've tried to retain as much of the knowledge as I can, but there was a lot of it. There to teach us that day was Jonathan, the full-time barista at Knockbox (previously the place was only open after hours), is the best kind of coffee nerd, imo - soft spoken, inconspicuous, but clearly open-minded and passionate, and like a walking, talking coffee encyclopaedia.

We started with a couple of us (there were only 4 in the class) making a cup of hand-drip. Just freestyle, however we liked. We tasted and noted the flavours.

Then Jonathan showed us a very basic guide to tasting - that's the flavour, nuttiness, acidity and body graph in the photo above. For each of the axes, we were told to think about whether the quality was positive/favourable - say, did the acidity have a pleasant citric quality, or did it make you cringe like white vinegar? Was the nuttiness like burned peanuts, or toasted hazelnut? We also talked about a pretty curious quality - the "makes you sick on the bus" quality - that is, the coffee doesn't taste bad when you're drinking it, but once you leave the shop and get on the bus (or take a break, or go to the bathroom, you get the idea) you feel a little uncomfortable - a mild feeling of indigestion or just a little hard to breathe. I wonder if there's a technical term for that...!

Then we got down to some details about the method Jonathan uses at Knockbox, namely dose, grind temperature and time. As you can see above, the dose is 15 grams of coffee for 180ml water, ground at a setting of "3" on their grinder (Fuji Royal? I forgot to check). The grinder size will never be the same on every machine, so I made sure I took a long hard look (and a photo, of course!) at the size (see below). The water temperature they use is at 83-86 degrees Celcius, and the brewing time (from the second the first drop of water touches the grounds) is around 90 seconds. The dose and time are very similar to what we were told at Rabbithole, from what I remember.

But, as we soon learn, these factors depend very much on the barista's own pouring skills. In a series of diagrams, we learned about the importance of fines (or rather, not having so many of them) - the smallest powdery bits from the grinding process; concentrating on pouring down the middle and to pour in a manner so as to have all the grounds wet at the same time (he did a cool experiment to show how the grinds move when you pour faster/more vigorously as opposed to a gentle pour); the way water "channels" through the easiest routes (yet we don't want it to do that as it means only the ground around that channel will come in contact with water), and so on. An important take-away for me was that the 90-second rule is, well, not a rule at all - use your eyes, says Jonathan, to see when the coffee is losing its colour as it drips out - common sense really, but hey, I never thought of it that way. Plus the baristas I've seen always have a stopwatch on the side! (Jonathan says he just does it for show, hahaha).

Grounds that brew for too long become overextracted, and apart from being able to taste this (in-your-face burnt bitterness, for instance), baristas talk about the percentage of coffee that has been dissolved in the water. The ideal, according to the Specialty Coffee Association of America (SCAA) is 20%+/- 2%, ie. 18-22%. They also have a snazzy machine called Extractmojo which can measure the Total Dissolved Solids (TDS) - basically how watery the coffee is. A TDS of 1.3 for example, means you have 98.7% water, and 1.3% coffee. However, as you can see from the diagram Jonathan drew on the tiled wall behind him, it could be that some grounds are at 13%, while others will have gone up to 25% because of different sizes and time that it's been in contact with water. The average will come out to be 19%, but you will still taste the parts that were 25%. Just because the numbers read right doesn't mean it'll taste good. The moral of that story is: trust your palate.

We also did a fun test with paper filters - debunking the myth that there is no taste to them. We blind tasted and compared water that was poured through an unwashed paper filter versus filter-free water. It was pretty obvious that paper does give off a funny taste.

I really appreciated the fact that Jonathan stressed that coffee, like anything else, is a matter of personal taste. Of course through trial and error, humans - professionals - have come up with ideal ranges and methods, and there are industry standards, and qualities that professionals look for in a coffee, but the bottom line is, no-one can dictate what you, personally, like and don't like.

Knockbox Coffee Company
Shop B, 14 Tai Ping Shan Street (tucked just off the street on the corner where Kouch cafe is, and yes, it is on the other side of the same building where Teakha is)
Sheung Wan
Hong Kong
8am-5pm Mon-Thu, 8am-10pm Fri, 1-6pm Sat-Sun

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  1. Wow, I've been brewing coffee for years, but I would like to take a class similar to the ones you've taken. There's always something new to learn and it's great to have someone who's passionate about what they're doing to lead the way. Yeah, I quit paper filters this past year. I know that they're convenient, but there's always that subtle taste that gets brewed in with the coffee.

    1. Yep, everyone has their own methods and philosophies so it's fun to see how they do it and why!

  2. PS have you seen the Able coffee metal aeropress filters... almost thinking about getting one. But the paper ones are so much easier and you can just wash them first.


    1. So many new toys to buyyyyy!! I definitely want to get a metal Aeropress filter for travel.