Cold brew coffee is extracted with cold or room-temperature water over 12–24 hours rather than hot water over minutes. The extended, low-temperature extraction produces a cup that is naturally sweet, smooth, and approximately 65% less acidic than hot-brewed coffee — not because you dilute it, but because the cold water extracts different chemical compounds than hot water does. This matters enormously for bean selection and brewing technique.
Why Cold Brew Needs Different Beans
Hot water extracts acidic, aromatic compounds quickly. Cold water is less efficient at this, which means light roast single origins — which shine in hot pour over because of their delicate aromatics — often produce flat, underdeveloped cold brew. Cold brew rewards medium to dark roast beans with chocolate, caramel, and nutty notes that emerge strongly under slow cold extraction. Brazilian Santos, Colombian Supremo, and Guatemalan blends are the classic cold brew origins for this reason.
Grind size matters significantly. Cold brew uses a coarse grind — similar to French press — to prevent over-extraction during the long steep. Pre-ground coffee sold specifically for cold brew is usually pre-ground at the correct coarseness. If you're grinding yourself, set your grinder to the coarsest setting.
Best Cold Brew Gear: The Mason Jar Method
You don't need specialized equipment for cold brew. A large mason jar, coarse-ground coffee, cold filtered water, and a fine mesh strainer or cheesecloth is the entire setup. The ratio is 1:4 coffee to water by weight for concentrate (dilute 1:1 with water or milk when serving), or 1:8 for ready-to-drink strength. Steep for 12–18 hours in the fridge. Strain twice through cheesecloth for the cleanest result.
That said, dedicated cold brew makers improve the process meaningfully. The OXO Good Grips Cold Brew Coffee Maker uses a rainmaker lid for even saturation and a perforated stainless steel filter that produces cleaner cold brew than cheesecloth with less effort. It makes 32oz of concentrate per batch and the glass carafe stores directly in the fridge.
Best Ready-to-Drink Cold Brew on Amazon
Chameleon Organic Cold Brew is the best shelf-stable RTD option — USDA Organic, 100% Arabica, genuinely smooth and full-bodied. Stumptown Cold Brew Stubby is a step up in specialty quality, using their Hair Bender blend specifically chosen for cold extraction. Both are available in multi-packs with Prime and represent the best of the RTD cold brew category.
Making Your Own: The Economics
A bag of quality cold brew beans at $15–$18 makes 8–10 servings of cold brew concentrate, each yielding 2–3 drinks when diluted. That's roughly $0.80–$1.20 per serving versus $4–$6 for a café cold brew. The 12–18 hour wait is passive time — actual hands-on effort is under 10 minutes. The economics of homemade cold brew are compelling for anyone who drinks it more than twice a week.
Verdict
For the best homemade cold brew: use a medium-dark Colombian or Brazilian whole bean, coarse grind, and the 1:4 ratio. For equipment: the OXO Cold Brew Maker is the best value upgrade over the mason jar method. For ready-to-drink: Stumptown Stubby for quality, Chameleon for value and organic certification.