Improving home brewed coffee
I assume that you already weigh your coffee and water, and grind beans before brewing your coffee. Give these things a try, and see if it improves your coffee.
Mineralise the water
Water from RO purifiers (soft water, less than 50ppm) are usually devoid of any minerals. Minerals with Calcium and Magnesium are essential for good extraction of coffee.
… if the motivation is to extract the most coffee constituents, then Mg2±rich water is most suitable. If the motivation is to achieve the best balance of flavors for a given lighter roast coffee, then both Ca2+ and Mg2+ do a comparable job, with Mg2+ having the added feature of preventing scale formation.
Excerpt from the paper, ‘The role of dissolved cations in coffee extraction.’
So, how can we add those minerals to the water? We can use mineralising water filter jugs, or mineral drops to add them to RO filtered water. But, they are expensive.
The cheapest alternative that works for me is Himalayan pink salt. Add a small pinch to a half litre of water before heating.
Heat the beans before grinding
Last one was easy, but this one needs a bit of patience.
Heat the coffee beans to around 60°C. With my 900W microwave, it takes around 50 seconds to reach that temperature. You need to experiment with your microwave to get the right duration.
Once you heat the beans, immediately grind the beans. Now, wait till the temperature drops below 35°C before you brew the coffee. I learned this technique from James Hoffmann’s weird coffee science video.
There you go, your coffee should taste better than before.