Cold Brew at Home: The SA Summer Recipe That Makes Itself

Cold brew is the highest ratio of quality-to-effort in all of coffee. Five minutes of actual work, twelve hours of the fridge doing your job for you, and you get a week's worth of smooth, low-acid concentrate that costs a fraction of the R45 cans the cool cafés on my 50 Coffee Shops list are selling. It's also the base of the espresso tonic — the drink of SA summer, and the easiest "wait, you MADE this?" you'll ever serve.

What You Need

• A big jar, a jug, or the plunger already in your cupboard (it moonlights beautifully as a cold brew vessel)
• 100g coffee, coarse grind — same sea-salt coarseness as plunger coffee
• 1 litre cold, filtered water — cold brew is unforgiving of bad water, and if your tap water is suspect (check the Water Quality Guide), filtered is non-negotiable here
• A sieve + paper filter, cloth, or the plunger's own screen

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The Recipe (Concentrate Method)

Ratio: 1:10 — 100g coffee to 1 litre of water. Makes concentrate you dilute to taste.

1. Coarse coffee into the vessel, cold water on top. Stir until every ground is wet. This is the entire skill component.
2. Cover. Fridge. 14–16 hours. Overnight plus a bit. Room temperature works in 12 but the fridge version tastes cleaner and this is Africa in January — fridge.
3. Strain gently. Plunger: press slowly and pour through a paper filter for a crystal-clear result. Jar: sieve first, then paper. Don't squeeze or press the grounds hard — that drags bitterness in.
4. Store sealed in the fridge. Perfect for 7 days.

To drink: dilute 1:1 with water or milk over ice. Straight over ice if you're built different.

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Three Things to Make With It

1. The Classic: concentrate + cold water 1:1, ice, done. Smooth, chocolatey, nearly zero acidity — this is the gateway drink for people who "don't like black coffee."

2. The Espresso Tonic (the summer one): tall glass, lots of ice, 200ml tonic water, then float 50ml of concentrate slowly over the back of a spoon. Slice of orange or a rosemary sprig if you're plating for Instagram. Yes, tonic. Trust the process — bitter-sweet-fizzy against smooth coffee is genuinely brilliant, and it's on every trending café menu for a reason.

3. The Cold Brew Dom Pedro-adjacent: concentrate + vanilla ice cream + a shot of your preferred adult ingredient, blended. I'm a coffee blog, not your sponsor, but it would be dishonest not to mention it exists.

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Beans

Cold brew mutes acidity and amplifies body — chocolate, caramel, nutty profiles win. It's also the most forgiving brew method on earth, which makes it the perfect retirement home for beans past their peak: that three-week-old bag that's gone flat for espresso will still make lovely cold brew. Fresh picks in this month's Top 5.

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The Maths

100g of a R160/250g specialty bag = R64 of coffee = roughly 5–6 large cold brews. That's ~R11 a glass for better-than-café cold brew, against R38–R48 out. Over an SA summer, the jar pays for a new grinder.

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FAQ

What's the cold brew ratio?

1:10 for concentrate (100g per litre), diluted 1:1 to serve. For ready-to-drink strength, brew at 1:15 and skip dilution.

How long should cold brew steep?

14–16 hours in the fridge. Under 10 is weak and sour-ish; past 20 it goes woody. It's forgiving, not immortal.

Is cold brew stronger than regular coffee?

The concentrate is, comfortably — which is why you dilute. Diluted, it's similar caffeine to filter but drinks smoother, so watch yourself.

Why is my cold brew bitter?

Grind too fine, squeezed the grounds while straining, or steeped 24+ hours. Coarse, gentle, 16 hours.

Cold brew vs iced coffee — what's the difference?

Iced coffee is hot coffee cooled down (fine, but acidic). Cold brew never touches heat — different extraction, much smoother result.