I get frustrated when people are more interested in how coffee looks than how it tastes. For me, coffee is all about taste, texture and temperature. Too many people worry about pretty patterns.
I’m sometimes asked what I look for in a good cup of coffee from another cafe. And to be honest, if I’m walking past 10 cafes on any street in Auckland, I would expect one to be amazing, three to be ok, and the rest to be shit. In other words, in six out of 10 cafes, you may as well give them the money without taking a coffee at all, and just walk out.
That sounds harsh, but unfortunately it’s true.
Everyone has their favourite brand, of course. But the first thing I look for is whether the coffee is from a NZ roaster. There’s a standard, the NZ Coffee Roasters Association, and that’s what I look for first.
Secondly, I listen for the noises coming from the machine. If there’s screaming coming from the steam wand, or you can hear the milk bubbling, don’t go in. Simple.
And if the cup is too hot to hold, that’s a guarantee the coffee will be bitter.
What ends up in your cup equates to 50 percent the barista, 25 percent the machine, and 25 percent the coffee. And it’s important that people know the difference between acidic or stronger coffee, and over-roasted coffee.
The best way to judge bitterness is by the taste in the back of your throat. It will sit there for ages. In laymen’s terms, if you get a shit taste in the back of your throat, then the barista has done something wrong. And that really comes down to the grind. And the barista controls the grind.
According to the textbooks, every barista has between 19 to 29 seconds to extract a standard 30mls of coffee. For me, I like a slower extraction, 27 seconds.
Over-extraction is about the colour. The first six seconds is what’s important. It’s like pressing grapes. The first press is where you have the full weight of the grapes and you get the free run juice. It’s the finest and the sweetest and the best. Coffee’s very similar. The first part of the extraction process is that free run juice. And then the longer you pour it, the more negative acidity goes into it—until it reaches a point where it goes from dark brown to a pale, faun colour. And that’s bitter.
Bitterness isn’t the same as acidic. Coffee is supposed to be acidic. From cafe to cafe, roast to roast, blend to blend, it’s always different. We roast our coffee quite light compared to Americans, the French and the Italians.
At Velvet, I roast fairly middle of the road. But I do see some NZ roasters who roast it quite light. And some roasters roast quite dark. It all depends on the origins you use. A number of roasters can cheapen their blend with robusta bean, which is usually quite cheap, and is there to soften the acidity of the coffee or give it a better crema. I only use 100 percent arabica coffee for reasons of quality and taste.
The water quality affects the end taste as well. So when you have a machine at home it’s always good to have it plumbed in and make sure you have a water filter or use only filtered water.
In cafes though, a lot comes down to the grind. If it’s a slower grind you are going to get more flavour, but you also have a higher chance the coffee will be bitter earlier in the pour. Grind and temperature relates directly to the pour and the grind can change from anything up to eight times or more a day, depending on the ambient temperature. If you’re in an air-conditioned place it generally won’t change. But when it is hot and humid the coffee absorbs moisture. It’s like a massive sponge. The moisture and heat content affects how it pours. So, in the morning you’ll find it pour slowly if it’s cold. As it warms, it becomes faster. A good barista will adjust their grind and watch the pour all the time.
The more humidity in the air, the finer you will go, because you want to slow the pour. If you’ve got a barista who doesn’t know what they are doing and they don’t adjust their grind, in the morning it might be perfect. But then by 11 o’clock it might be persisting out. And you’ll just get an under-extracted coffee, which gives you almost the same flavour as an over-extracted coffee. It will taste bitter.