What's the Best Coffee for Cold Brew at Home? (Australia Guide)

Cold brew has moved well past trend territory. It's a legitimate brew method with a genuinely different flavour profile to iced coffee, and more Australians are making it at home than ever. The problem is that most of the advice online is written for American audiences using American products, and some of it is just wrong. This is the Australian version.

What cold brew actually is, and why it matters for bean selection.

Cold brew is made by steeping coarsely ground coffee in cold or room temperature water for an extended period, typically 12 to 24 hours, then filtering out the grounds. No heat is involved at any point.

This is fundamentally different from iced coffee, which is hot-brewed coffee poured over ice. The absence of heat changes everything about how flavour compounds are extracted. Heat extracts quickly and pulls a wide range of compounds including brighter acids and volatile aromatics. Cold water extracts slowly and selectively, favouring sweeter, heavier, more chocolatey compounds while leaving behind a lot of the sharper acidity.

The result is coffee that tastes smoother, less acidic, and naturally sweeter than the same beans brewed hot. Understanding this changes how you should think about bean selection.

Does roast level matter for cold brew?

Yes, but not in the direction most people assume.

The common advice is to use dark roasts for cold brew because they're bold and strong. That's not wrong exactly, but it's incomplete. Dark roasts in cold brew can taste flat, slightly bitter, and one-dimensional because cold extraction can't pull the complexity out of a heavily developed roast the way hot brewing can.

Medium roasts tend to perform better than people expect in cold brew. The natural sweetness and moderate acidity that makes a medium roast enjoyable as espresso or filter also translates well to cold extraction. You get a rounded, full-flavoured result without the bitterness that can creep into very dark cold brews. Our Liberty Blend is a medium roast that works particularly well here.

Lighter roasts can work in cold brew but they're the trickiest to get right. The bright acids that make a light roast interesting as a hot filter coffee can sometimes come across as thin or sour in cold brew if the steep isn't long enough. If you want to experiment with lighter roasts in cold brew, extend your steep time toward the 20 to 24 hour end.

The grind size question.

Cold brew uses a coarse grind, significantly coarser than filter coffee and worlds away from espresso. You're looking for something roughly the consistency of raw sugar or coarse sea salt.

The reason is contact time. Because cold brew steeps for 12 to 24 hours, a finer grind would massively over-extract and produce something bitter and harsh. The coarse grind slows extraction to match the long steep time.

If you're grinding at home, a burr grinder like the Breville Smart Grinder Pro or the compact Porlex Mini Hand Grinder will give you the consistent coarse grind cold brew needs. Set your grinder well above filter range and don't be alarmed by how coarse it looks. If you're buying pre-ground, purpose-ground cold brew grind from a roaster is ideal. Standard pre-ground espresso or even filter grind will over-extract in cold brew.

Ratios for cold brew at home.

The standard starting point is a 1:8 ratio of coffee to water by weight. So 100 grams of coffee to 800ml of water produces a reasonably strong cold brew concentrate that you can drink straight or dilute.

If you want a concentrate to mix with milk or dilute further, move toward 1:5 or 1:6. If you prefer something ready to drink without diluting, 1:8 to 1:10 gives you that.

Experiment with your first batch to find where you like it. The beauty of cold brew is that the process is forgiving and the result keeps well in the fridge for up to two weeks.

Blends vs single origins for cold brew.

Blends tend to work reliably well for cold brew. The consistency and balance that makes a good espresso blend perform across different machines and techniques also means it behaves predictably in cold extraction. If you want something to make in regular rotation without overthinking it, a medium roast espresso blend like our Liberty Blend is a safe and genuinely good choice.

Single origin coffees can be exceptional in cold brew, particularly naturals and honey processed coffees. The processing method affects the flavour compounds in the bean, and natural processed coffees (where the fruit dries on the bean before processing) tend to have more inherent sweetness and body that cold brew amplifies beautifully. A natural Ethiopian or Brazilian in cold brew can produce something almost fruit-juice-like in the best possible way.

Washed single origins in cold brew are more variable. Some are lovely. Some taste thin. It depends heavily on the specific coffee and how far the roast has been taken.

What to avoid.

Supermarket coffee is a poor choice for cold brew for the same reason it's a poor choice for any brewing method, but the long steep time amplifies staleness rather than hiding it. Old beans produce a dull, flat cold brew that no amount of technique will rescue.

Very dark, oily roasts can work but tend toward bitterness and a heavy, almost syrupy quality that some people like and others don't. If you've tried cold brew and found it too heavy or slightly harsh, the roast level is the first thing to reconsider.

Avoid fine or medium-fine grinds entirely. They will over-extract and produce something unpleasant regardless of how good the beans are.

A simple cold brew method to start with.

Coarsely grind 100 grams of a medium roast coffee. Add to a large jar or jug with 800ml of cold filtered water. Stir briefly to make sure all the grounds are saturated. Cover and leave in the fridge for 14 to 18 hours. Strain through a fine mesh strainer lined with a paper filter or a clean cloth. What's left is cold brew concentrate ready to drink over ice, with milk, or diluted with water to taste.

That's the whole process. Once you've done it once you'll wonder why you waited.

If you'd rather skip the steep altogether, our BOOM Cold Brew Concentrate is made the same way and arrives ready to pour. Just dilute and drink.