Cold Brew Recipe

What You'll Need

Equipment:

For a simple home setup, use:

  1. Cold Brew Coffee System or a clean glass jar with a lid.
  2. Grinder or preground coffee (not ideal)
  3. Coffee scale
  4. Coffee Filter (Can Use With V60, a fine-mesh filter, filter paper or reusable filter bag)
  5. Long spoon or stirring paddle
  6. Airtight bottle for storage

Recommended cold-brew makers:

Best fit for Cold Start: Hario Mizudashi

The Hario Mizudashi uses a removable fine-mesh basket: add coffee, pour in water, refrigerate and remove the filter when brewing is complete. Its straightforward design and clean glass appearance would also suit the Cold Start visual style.

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Best for concentrate: OXO Cold Brew Maker

The OXO system is designed to produce concentrated cold brew and uses a rainmaker-style top to distribute water over the grounds. OXO recommends diluting its finished concentrate with approximately two or three parts water or milk.

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Best for larger batches: Toddy Home System

The Toddy system is useful when producing a larger quantity of concentrate. Its official guidance recommends beginning with one part concentrate to two parts water or milk, adjusting to taste.

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Advised Methods:

Step 1: Measure and Grind Coffee

Weigh:

  • 50g freshly roasted coffee
  • 400g filtered water

Your grind size plays a vital role in the final cup. Use a coarse grind—slightly coarser than you would for a French Press or pour-over. This allows the coffee to extract slowly over many hours, producing a smooth, naturally sweet brew with low acidity.

A grind that's too fine can slow or even block filtration, making the coffee difficult to drain and potentially introducing unwanted bitterness. For the cleanest extraction, we recommend placing a paper filter inside the reusable mesh or felt filter before brewing. This helps prevent clogging, improves clarity in the finished coffee, and makes cleanup much easier once brewing is complete.

Before brewing, prepare your filter. If you're using a felt filter for the first time, soak it in warm water for 1–3 minutes, wring out the excess water, and fit it into the base of your brewer. Shape it into place to create an even seal.

For a cleaner brew and easier cleanup, place a paper filter on top of the felt filter before adding your coffee. This helps prevent clogging and improves filtration.

Filter Care:

  • Rinse the felt filter thoroughly after each brew.
  • Store it in a sealed bag in the freezer between uses.
  • Before brewing again, sanitise it by soaking it in boiling water for 1–3 minutes, then rinse with cold water and wring dry.
  • Replace the felt filter after approximately 10 brews for the best results.

Step 3: Add Coffee, Water and Mix

Coffee Amount: 50g

Water Amount: 400 grams

Temperature: Room temperature or cold water

Place the 50g of ground coffee into your cold-brew brewer, filter basket or clean glass jar.

Slowly pour the water over the grounds, working across the entire coffee bed rather than pouring into one place. Make sure every ground is fully saturated.

Gently stir once or twice. Avoid vigorous stirring, which can increase sediment and make filtration more difficult.

Cover the brewer and place it in the refrigerator.

Leave it to steep for:

12–18 hours

Twelve hours will usually produce a lighter, cleaner brew. Moving towards 18 hours creates greater strength and body. Most cold-brew guide lines similarly place the general brewing window between 12 and 24 hours.

Cold Start note: Time does the work here. Start at 14 hours, taste the finished brew, then adjust your next batch rather than changing several variables at once.

Step 5: Dilute, Serve and Enjoy!

Because your 1:8 recipe creates a strong drink, begin by tasting it undiluted.

Then adjust with:

  • A small amount of filtered water for a lighter black cold brew
  • Milk or oat milk for a smoother finish
  • Equal parts cold brew and water for a softer cup
  • A little simple syrup when sweetness is preferred

More specifically:

Recipe Suggestion (1): 170g or 6 ounces of cold brew concentrate and 113g or 4 ounces of spring water.

Recipe Suggestion (2): 170g or 6 ounces of cold brew concentrate and 113g or 4 ounces of milk or milk alternative.

Your final beverage is what is considered a cold brew concentrate. You can certainly drink it as is or add 1 to 2 parts of water or milk to your cup. Cold brew refrigerated with nothing added to it will stay good for 7 – 10 days.

Cold Start Tip: Store in the fridge for up to 7-10 days for the best flavour.

Frequently asked questions

What is the best Grind Size for Cold Brew?

Grind: Coarse (slightly coarser than a French Press), with a texture similar to coarse sea salt. This allows the coffee to extract slowly, producing a smooth, naturally sweet cold brew with low acidity.

Cold Start Tip: Grind fresh immediately before brewing. A consistent coarse grind is one of the biggest factors in producing a clean, balanced cold brew. If your brew tastes bitter, grind coarser. If it tastes weak or hollow, grind slightly finer on your next batch.

If you're using a burr grinder

A few starting points (these vary slightly by grinder):

  • Baratza Encore: 30–34
  • Wilfa Uniform: 32–36
  • Fellow Ode Gen 2: 8–10
  • Comandante C40: 38–42 clicks
  • Niche Zero: 50–60

These are excellent starting points, but always adjust based on taste and your brew time.

Why it matters:

Grind SizeResult:

  • Too Fine: Over-extracts, resulting in bitterness, muddiness, and excessive sediment. It can also clog paper or felt filters, slowing or preventing drainage.
  • Ideal Coarse: Produces a smooth, clean, naturally sweet cold brew with balanced extraction and easy filtration.
  • Too Coarse: Under-extracts, giving a weak, watery cup with reduced sweetness and body.
Where should I Store my cold brew?

Cold Start Recommendation

  • Store in a clean, airtight glass bottle or carafe.
  • Keep refrigerated at 1–4°C.
  • Avoid leaving it at room temperature for extended periods.
  • Keep the lid tightly sealed to minimise oxidation and prevent the coffee from absorbing odours from other foods.

How long does it last?

  • Best flavour: Within 5–7 days.
  • Still enjoyable: Up to 10 days, although you'll notice a gradual loss of sweetness and clarity.

If you've brewed a concentrate, it can often keep for up to two weeks when refrigerated, but for the highest quality and the flavour standards of Cold Start, we recommend enjoying it within one week.
How frequently should reusable felt filters be replaced?

Most reusable felt filters should be replaced after approximately 10 brewing cycles, although this can vary slightly depending on the manufacturer and how well they're maintained.

To maximise the life of your felt filter:

  • Rinse thoroughly after every brew.
  • Store it in a sealed bag in the freezer between uses to help prevent bacteria growth.
  • Before brewing again, sanitise it by soaking it in boiling water for 1–3 minutes, then rinse with cold water and wring it dry.
  • Replace it sooner if it becomes discoloured, develops an odour, tears, or no longer filters effectively.
what is the difference between Iced coffee and Cold Brew?

Brief Comparison:

Iced Coffee

Iced coffee is brewed hot using methods such as espresso, pour-over or drip coffee, then cooled and served over ice. It retains the bright acidity and complex flavours of hot coffee while offering a refreshing, chilled drink.

Cold Brew

Cold brew is made by steeping coarse coffee grounds in cold water for 12–18 hours. This slow extraction produces a naturally sweeter, smoother coffee with lower acidity and a fuller body, making it ideal for drinking over ice or with milk.