Most home brewing problems are not equipment problems. They are variable problems, and they are usually being solved in the wrong order.

Start with the dose. Sixty grams of coffee per litre of water is a sensible place to begin — for a single V60 that is fifteen grams to two hundred and fifty. Weigh it. Volume measures drift by twenty percent or more depending on the roast.

Then fix the water. Filtered, around 94°C for a light roast, a few degrees cooler for anything darker. Hard water mutes acidity; distilled water strips the cup of body entirely.

Only then start moving the grind. If the brew finishes early and tastes thin and sour, go finer. If it stalls and tastes drying and bitter, go coarser. Change one thing at a time, and give yourself two brews before deciding anything.