If you've ever looked at a cold brew setup and felt like everyone else knows a secret you don't, you're not alone. Cold brew looks dead simple—coffee, water, time—but the details decide whether your jar tastes like chocolatey sunshine or bitter regret. Here's the map of what actually matters.

• Coffee: the star. Use a medium roast like RAMI's. It's forgiving and brings out natural sweetness.
• Grind: coarse. Think breadcrumbs, not sand. Fine grounds turn cold brew muddy and bitter.
• Water: cold or room temperature. Filtered water helps, but tap is fine if it tastes good.
• Ratio: the dial. More coffee = stronger concentrate. Less = ready-to-drink.
• Time: patience. 18 hours is the sweet spot.
• Filtration: the cleanup. Twice filtering gives you that clear, clean cup.