How to Make Cold Brew Coffee at Home Like a Barista

Cold brew coffee is one of the easiest café-quality drinks to make at home, but most people either over-steep it into bitterness or under-extract it into something flat and watery. This guide gives you the exact ratios, grind size, and steeping method to produce cold brew that is smooth, sweet, and consistent every time.

What Is Cold Brew Coffee?

Cold brew coffee is made by steeping coarsely ground coffee in cold or room-temperature water for an extended period — typically 12 to 24 hours — and then straining the grounds out to produce a smooth, concentrated liquid.

No heat is used at any point. This is the defining feature of cold brew and the reason it tastes so different from hot coffee that has been cooled down. Without heat, the extraction process is slower and gentler, which limits the extraction of bitter and acidic compounds. The result is a coffee that is naturally sweeter, less acidic, and smoother than hot espresso or filter coffee served cold.

Cold brew is not the same as iced coffee (a hot-brewed coffee poured over ice) or cold drip (where cold water drips slowly through a coffee bed under gravity using specialised equipment). Cold brew is the simplest of the three methods and the easiest to replicate at home.

Cold Brew vs Iced Coffee: What Is the Difference?

The most common point of confusion is between cold brew and iced coffee.

Iced coffee is brewed hot using espresso or filter methods, and then chilled or poured directly over ice. The flavour profile is the same as hot coffee, with the same acidity and bitterness, diluted by the melting ice. Some venues brew iced coffee directly over ice to minimise dilution.

Cold brew is never heated. The absence of heat extracts fewer acidic and bitter compounds over the longer steeping time, producing a noticeably different flavour profile even when made from the same beans.

If you have ever found hot coffee too acidic or bitter but enjoyed a cold brew at a café, this is why. The extraction chemistry is fundamentally different.

Cold Brew Coffee Ratio

The ratio of coffee to water determines whether you are making a concentrate or a ready-to-drink cold brew.

For a cold brew concentrate (the most versatile option, typically diluted 1:1 with water or milk before serving): use a ratio of 1:4 (one part coffee to four parts water by weight). For example, 100 grams of coffee to 400ml of water.

For a ready-to-drink cold brew (drink it straight from the jar): use a ratio of 1:8. For example, 100 grams of coffee to 800ml of water.

Weighing your ingredients produces more consistent results than measuring by volume, particularly when you are dialling in your preferred concentration.

Grind Size for Cold Brew

Use a coarse grind — coarser than you would use for any espresso preparation and similar to a coarse sea salt texture. A coarse grind slows the extraction rate appropriately for the long steeping time. If you use a fine grind, you will over-extract the coffee into bitterness, and the grounds will be difficult to filter out cleanly.

If you do not have a grinder at home, ask your local roaster to grind the beans coarsely for you when you purchase. For pre-ground supermarket coffee, use filter-ground products rather than espresso-ground.

How to Make Cold Brew at Home: Step-by-Step

What you need: coarsely ground coffee, cold or room-temperature filtered water, a large jar or container, a fine-mesh strainer or cheesecloth, and time.

Step 1: Combine coffee and water. Add your measured coffee grounds to a large jar or container. Pour the measured water over the grounds and stir gently to ensure all the grounds are saturated. There should be no dry pockets of coffee.

Step 2: Cover and steep. Cover the jar loosely and leave it to steep at room temperature for 12 to 18 hours, or in the refrigerator for 18 to 24 hours. Room-temperature steeping is faster; refrigerator steeping is slower but produces a cleaner, slightly different flavour.

Step 3: Strain. Pour the steeped mixture through a fine-mesh strainer lined with a paper coffee filter or cheesecloth into a clean jar. Do not press or squeeze the grounds — let gravity do the work. Squeezing the grounds releases bitter compounds.

Step 4: Store and serve. Transfer the strained cold brew to a sealed jar or bottle and refrigerate. Cold brew concentrate keeps well for up to two weeks in the refrigerator. Ready-to-drink cold brew is best consumed within one week.

Step 5: Dilute and serve. If you made concentrate, dilute with equal parts cold water or milk over ice before serving. If you made ready-to-drink cold brew, pour straight over ice.

Steeping Time: How Long Is Long Enough?

Steeping time is the variable most beginners get wrong. Under-steeping (less than 10 hours at room temperature) produces a weak, flat result. Over-steeping (more than 24 hours) can produce bitter, astringent notes.

Start with 12 to 14 hours at room temperature as your baseline. Taste the result before straining — it should taste smooth, sweet, and concentrated. If it tastes bitter, shorten the steep time next batch. If it tastes flat or weak, extend the steep time or increase the coffee dose.

The ideal steep time also depends on the coffee you are using. Lighter-roasted, more acidic coffees often benefit from a slightly shorter steep to avoid over-extraction of tannins. Darker roasts are more forgiving and can handle longer steeping.

Which Coffee Beans Work Best for Cold Brew?

Almost any coffee produces a drinkable cold brew, but medium and medium-dark roasts tend to work best as a starting point. Their balanced acidity, chocolate, and caramel notes express well in cold extraction and produce a naturally sweet, approachable drink.

Light-roast specialty coffees can produce interesting cold brews with fruit-forward profiles, but they require slightly more precise steeping to avoid under-extraction. Dark roasts can work well but sometimes produce a heavy, smoky result that divides opinion.

Single-origin Ethiopian or Kenyan coffees produce particularly interesting cold brews with fruit and floral character. Colombian and Brazilian coffees produce reliable, crowd-pleasing cold brew with chocolate and nut notes.

Cold Brew at Barista Course Adelaide

Understanding cold brew is part of a barista’s broader knowledge of extraction methods. If you want to understand the science behind coffee extraction, whether it is espresso, filter, or cold brew, the Barista Pro Complete Training at Barista Course Adelaide covers the foundations in a practical, hands-on session. See the course calendar for available dates at our Adelaide CBD training centre or Salisbury location.