If your coffee tastes sour and thin, grind finer. If it tastes bitter and dry, grind coarser. Change one thing at a time and keep the dose and water the same.
For a V60 start at 15 g of coffee to 250 g of water, a medium-fine grind and a total brew time near three minutes. Adjust the grind in small steps and taste after each brew.
When you order from us you can pick whole bean or have it ground for your brewer. Whole bean keeps its aroma longer, so grind just before you brew if you can.