How to Make Cold Brew for a Crowd (Easy Batch Recipe)

The standard cold brew ratio for a crowd is 1:8 by weight for concentrate (dilute 1:1 before serving) or 1:16 by weight for ready-to-drink. For a ready-to-drink 1-gallon batch, that is 237 g of coarsely ground coffee to 3.8 L of cold filtered water — steep 16–20 hours in the refrigerator, double-strain, and serve over ice. One gallon of ready-to-drink cold brew yields 16 eight-ounce servings; one gallon of concentrate yields 32 servings once diluted 1:1.

Three things ruin a crowd-sized batch: grinding too fine (bitter, over-extracted coffee), skipping the double-strain (gritty texture), and using chlorinated tap water (flat, chemical off-notes). Filtered or spring water is worth the extra step at any size, but especially when you are brewing 1–2 gallons and water makes up 94% of the cup. Get those three variables right and large-batch cold brew is almost impossible to ruin.

Quick Answer: Cold Brew Batch Sizes at a Glance

Every row below uses the 1:16 ready-to-drink ratio. For concentrate, halve the water and dilute 1:1 with water or milk before serving.

Batch Size	Ground Coffee	Cold Water	Fridge Steep	Servings (8 oz)
1 qt (0.95 L)	60 g	950 ml	16–18 hrs	4
2 qt (1.9 L)	119 g	1.9 L	16–20 hrs	8
1 gal (3.8 L)	237 g	3.8 L	18–20 hrs	16
2 gal (7.6 L)	475 g	7.6 L	18–24 hrs	32

What You Need Before You Start

Large-batch cold brew needs little equipment. You need a food-safe container with a lid (a wide-mouth 1-gallon mason jar, a 2-gallon food-safe bucket, or a dedicated cold brew maker), a fine-mesh strainer, unbleached paper coffee filters or a reusable cold brew filter bag, and a clean pitcher or carafe for the finished brew. A kitchen scale is strongly recommended — measuring by grams rather than scoops keeps results consistent every time you scale up.

For the coffee, choose a medium or dark roast with chocolate, nutty, or caramel notes. Those profiles extract smoothly over a long cold steep and tend to please a crowd. Bright, high-acid light roasts can taste sharp in cold brew. Grind coarse — the texture of raw sugar or coarse sea salt. Fine grounds over-extract during the long steep and turn the batch bitter and astringent. If you grind at home, set your burr grinder to its coarsest setting. Water quality matters more than most guides admit: chlorinated tap water is a known cold brew flavor killer at any size, and the effect is amplified across 1–2 gallons. Use filtered or spring water.

Step-by-Step: How to Make Cold Brew for a Crowd

Step 1 — Measure and Grind

Decide on your ratio before grinding. For ready-to-drink cold brew, use 1:16 by weight (1 g coffee per 16 g water). For concentrate that guests dilute themselves, use 1:8 (1 g coffee per 8 g water). For a 1-gallon ready-to-drink batch: 237 g coffee, 3.8 L water. Grind coarse — if the grounds look like fine sand, they are too fine and will over-extract.

Step 2 — Combine Coffee and Cold Filtered Water

Add the ground coffee to your container, then pour cold filtered water over it. Stir gently to saturate every ground — dry pockets on top will not extract and leave the batch uneven. Seal or cover the container loosely.

Step 3 — Steep in the Refrigerator

Place the covered container in the refrigerator and steep for 16–20 hours at 35–40°F (2–4°C). Fridge-steeping produces cleaner, less acidic cold brew than room-temperature steeping because the lower temperature slows extraction and suppresses bitter compounds. Do not exceed 24 hours — over-steeping introduces bitterness even with a coarse grind.

Step 4 — Double-Strain

Pour the brew through a fine-mesh strainer lined with an unbleached paper coffee filter into a clean pitcher or carafe. For large batches, work in stages. The double-strain removes fine sediment that makes cold brew taste gritty or muddy. Do not press or squeeze the grounds — that forces bitter compounds into the finished brew.

Step 5 — Serve and Store

Serve immediately over ice, or seal and refrigerate. Ready-to-drink cold brew is best within 7–10 days of straining; concentrate keeps up to 14 days. Label the container with the brew date. For a party, brewing 18–20 hours before guests arrive gives you freshly extracted, peak-quality cold brew — not a batch that has been sitting for days and started to flatten.

Scaling for a Party: How Much Do You Actually Need?

Plan for 1.5 eight-ounce servings per guest to cover refills. For 20 guests, that is 30 servings — a 2-gallon ready-to-drink batch (475 g coffee, 7.6 L water) or a 1-gallon concentrate batch diluted 1:1 at serving. Brew the evening before the event so the full 18–20 hour steep fits naturally into your schedule and the cold brew is freshly strained when guests arrive.

If you want to dial in your roast profile for cold brewing rather than buying pre-ground, SERA's Coffee Machines & Roasters collection includes home roasting equipment that lets you control roast level and development time — both of which directly shape cold brew sweetness and body.

Common Mistakes When Making Cold Brew for a Crowd

• Grinding too fine. The most common error. Fine or medium grounds over-extract during the long cold steep and turn the batch bitter and astringent. Always use a coarse grind — the texture of raw sugar.
• Using chlorinated tap water. Chlorine suppresses coffee aromatics and adds a flat, chemical note that is especially obvious in cold brew. Use filtered or spring water, particularly for batches of 1 gallon or more.
• Steeping at room temperature for large batches. Room-temp steeping is faster but less controlled and more prone to off-flavors. For crowd-sized batches, always steep in the refrigerator.
• Skipping the double-strain. A single pass through a mesh strainer leaves fine sediment. Line the strainer with a paper filter for a clean, smooth pour.
• Not tasting before serving. Batches vary by bean and grind. Taste a small sample diluted 1:1 with water before serving, then adjust dilution at the dispenser if needed.

FAQ: Cold Brew for a Crowd

What is the best coffee-to-water ratio for cold brew concentrate?

The best ratio for cold brew concentrate is 1:8 by weight — 1 gram of coarsely ground coffee per 8 grams (ml) of cold filtered water. Dilute 1:1 with water or milk before serving. For ready-to-drink cold brew, use a 1:16 ratio.

How long should I steep cold brew in the fridge?

Steep cold brew in the refrigerator at 35–40°F (2–4°C) for 16–20 hours. Steeping longer than 24 hours introduces bitterness even with a coarse grind. For a party, start the batch the evening before the event so it is freshly strained when guests arrive.

How many servings does a 1-gallon cold brew batch make?

A 1-gallon (3.8 L) ready-to-drink cold brew batch yields 16 eight-ounce servings. A 1-gallon concentrate batch (brewed at 1:8) yields 32 eight-ounce servings when diluted 1:1 with water or milk before serving.

What grind size is best for large-batch cold brew?

Use a coarse grind — similar in texture to raw sugar or coarse sea salt. Fine or medium grinds over-extract during the long cold steep and produce a bitter, astringent batch regardless of batch size.

Does water quality affect cold brew flavor?

Yes. Chlorinated tap water suppresses coffee aromatics and adds a flat, chemical off-note that is especially noticeable in cold brew. Use filtered or spring water for any batch, and especially for batches of 1 gallon or more where water makes up 94% of the final cup.

Quick Recap

• Use 1:16 by weight for ready-to-drink cold brew; 1:8 for concentrate (dilute 1:1 before serving).
• Grind coarse — raw sugar texture — to prevent over-extraction and bitterness.
• Use filtered or spring water; chlorinated tap water kills cold brew flavor at any batch size.
• Steep 16–20 hours in the fridge at 35–40°F (2–4°C); never exceed 24 hours.
• Double-strain through a mesh strainer lined with a paper filter for a clean, sediment-free pour.
• A 1-gallon ready-to-drink batch serves 16 guests; a 1-gallon concentrate batch serves 32 guests diluted 1:1.
• Brew 18–20 hours before the party for freshly extracted, peak-quality cold brew at serving time.