[vient]

> A lot of 'premium' branded instant coffee is ~£42/kg. That's £3/kg more than my premium, locally-roasted, single-estate Colombian coffee beans.

You need 7-10 times less instant coffee to make a cup though, so your beans are a lot more expensive in the end. From my experience, cup of coffee is either 2 grams of Nescafe Gold or 16 grams of beans.

[Error9632]

The 7-10 times seems quite off. It’s pretty close to 5 times assuming common extraction yields about 20%. So instead of brewing 16g of coffee you could dissolve 3.2g of instant.

[maxbond]

For what it's worth I just checked my store brand instant, and the serving suggestion is 1.9 grams.

[Error9632]

All depends on the concentration you are trying to achieve. If you brew 16g of coffee, you'd usually end up with around 260g of finished brew.