How much coffee for cold brew?

For a concentrate you dilute in the cup, 1:5 by weight (1 g coffee to 5 g water, so 200 g coffee per liter) is the most common starting point. A 1:4 cold brew concentrate ratio (250 g per liter) is Toddy-style and stronger, and 1:3 is super concentrate. For ready-to-drink cold brew you sip straight, 1:8 works (125 g coffee per liter). The calculator defaults to 1:5 medium and adjusts brew time and dilution math automatically.

Concentrate is brewed strong (1:3 to 1:5 by weight) and diluted in the cup. Ready-to-drink is brewed weaker (around 1:8) and sipped straight. A 1:8 cold brew ratio means 1 part coffee to 8 parts water by weight, so 125 g of coffee per liter of water, or about 30 g coffee per cup of water. We measure by weight and label the output as concentrate; some recipes instead describe the final drink ratio after dilution, which is why 1:5 can equal a 1:8 cup once you add water.

A quart is about 950 ml of water. At a 1:5 concentrate ratio by weight, that is roughly 190 g of coffee (about 2 cups of grounds). At 1:8 ready-to-drink it is about 120 g, and at a 1:4 ratio about 235 g. Set servings and cup size in the calculator and it gives the exact grams of coffee and milliliters of water for any batch size, including a quart or a full liter.

Standard 1:5 concentrate: pour 4 oz of concentrate plus 8 oz of cold water or milk over ice in a 12 oz cup. Stronger 1:3 concentrate: pour 3 oz concentrate plus 9 oz of water. As a rule, concentrate gets diluted 1:1 to 1:3 with water or milk to taste. The calculator does this math automatically and shows the exact pour per serving for your chosen cup size and strength.

12 to 18 hours in the fridge for most setups, 16 hours is the sweet spot for a 1:5 concentrate with coarse grind. Stronger ratios (1:3, 1:4) need 16 to 20 hours for full extraction. Room temperature shortens this by about 4 hours (Toddy is designed for room temp). Slow drip systems run 4 to 8 hours.

Coarse, like kosher salt or coarse sea salt. Pre-ground 'cold brew' bags are usually this size. Too fine and the brew turns muddy and over-extracts (bitter, sour). Too coarse and the brew is weak. A 9 to 11 setting on a Baratza Encore or equivalent works for most setups.

Yes, any coffee works, but medium to medium-dark roast is typically best. Cold extraction pulls fewer acids and bitter compounds than hot water, so it pairs well with chocolate and nutty notes from medium-dark beans. Light roasts can taste flat or tea-like. Espresso beans work too (dark roasts give a rich, chocolatey, sometimes smoky cup), but buy them whole and grind coarse, since pre-ground espresso is too fine and over-extracts.

Per ounce of concentrate, yes. Cold brew concentrate at 1:5 has roughly 200 mg caffeine per 8 oz, versus a 12 oz drip coffee at about 120 mg. After dilution in the cup it lands closer to a standard cup. The calculator estimates per-serving caffeine based on your bean weight and ratio (12 mg caffeine per g dry beans, 85% extraction).

Undiluted concentrate keeps 10 to 14 days sealed in the fridge. Diluted cold brew (1:1 with water) keeps about 4 to 7 days before it starts to taste flat. Always store sealed and out of light. If you see any film or smell anything sour, toss it.

Bitter = over-extracted, usually too fine a grind or too long a steep. Drop to 14 hours or grind coarser. Sour = under-extracted, often light roast or too short a steep. Push to 18 hours or use a darker roast. Weak = ratio too dilute or grounds absorbed too much water. Use 1:5 or stronger and check your water-to-coffee math.

Iced coffee is hot-brewed coffee poured over ice. It is fast (5 minutes) but more acidic and bitter. Cold brew is brewed cold over 12 to 18 hours. The cold extraction pulls fewer acids (about 67% less than hot brew per Caporaso 2014), so the flavor is smoother and less bitter. Cold brew also has more caffeine per ounce as a concentrate.

Yes, if your tap water tastes off. Cold brew is mostly water, so off flavors come through. Filtered or bottled spring water with 50 to 150 ppm dissolved solids gives the cleanest cup. Avoid distilled water (too flat) and very hard water (chalky). A Brita filter is enough for most kitchens.

There is no fixed volume, because cold brew strength swings with your ratio, steep time, and how much you dilute. For reference, a 1 oz home espresso shot is about 64 mg of caffeine and a Starbucks shot is about 75 mg. Undiluted 1:4 concentrate can run well past that in a single ounce, while a 1:10 ready-to-drink batch may take 4 to 6 oz to match one shot. Use the caffeine estimate this calculator produces for your exact ratio and dilution rather than a rule of thumb.