About $350 a year — that’s the swing for a household that drinks an iced coffee a day from May through September and switches the source from grocery-store cold brew concentrate ($9 a quart) to homemade ($1.80 a quart). The ingredients are the same; the difference is buying coffee that’s already been brewed versus brewing it yourself. The brewing takes ten minutes of active work and twelve hours of sitting on the counter.
This piece is the method, plus what kind of beans actually matter (less than you’d think) and why this is the piece of home coffee gear that’s easiest to nail.
The method
You need: a mason jar (1 quart or larger), a fine-mesh strainer, a paper coffee filter, coarse-ground coffee, water. That’s everything.
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Combine coffee and water in the jar. The ratio: 1 cup coarsely ground coffee to 4 cups room-temperature filtered water (a 1:4 ratio for concentrate). Stir to make sure all grounds are wet.
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Lid on, counter or fridge, 12–18 hours. The counter is fine for this; cold brew is acidic enough that nothing scary grows. 12 hours produces a milder concentrate; 16 is the sweet spot; 18+ starts to taste over-extracted.
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Strain twice. First through the fine-mesh strainer to catch the bulk of the grounds. Then through a paper coffee filter sitting in the strainer over a clean container — this catches the fines that make cold brew taste sandy. The second pass takes 20 minutes; do it while you’re doing something else.
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Store in the fridge. Lasts two weeks in a sealed bottle. After two weeks the flavor flattens; after three, it gets papery.
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Drink diluted. Concentrate is just that: concentrated. Pour 4 oz of concentrate over ice and top with 4 oz of water (or milk, or oat milk). That’s the standard iced coffee. Adjust to taste.
Summer-season iced coffee$350/year
The cost math
For a typical batch:
- 1 cup of coarsely ground coffee weighs about 80 grams. A 12 oz bag of coffee (340g) at $14 yields ~4 batches.
- 4 cups of water is essentially free — pennies of municipal tap, even if filtered.
- Per batch: ~$3.50 in inputs, yielding 1 quart of concentrate, which is 8 servings of iced coffee.
- Per serving: about $0.45.
Compare to:
- Grocery cold brew concentrate at $9/qt = $1.10 per 4-oz pour.
- Coffee shop iced coffee: $5–6.
A daily summer iced coffee at $0.45 vs $5 at a shop = $4.55 saved per day, $686 over a 150-day summer. Even versus the grocery concentrate, the savings is real: ($1.10 – $0.45) × 150 = $98 per year for grocery-versus-DIY alone, before you account for the fact that the homemade version tastes substantially better than the bottled stuff.
The $350 figure in this piece blends both: some of your iced coffee was previously coffee shop, some was previously grocery concentrate, and the homemade version replaces both.
What kind of beans
Less particular than hot coffee. A medium roast is ideal; cold brew tends to mute the differences between beans, so a $14-a-pound supermarket specialty roast performs almost identically to a $24-a-pound boutique bean. This is the rare case where store-brand specialty coffee is the right answer.
What matters more than origin: freshness (a bag roasted in the last six weeks; check the date on the bag) and grind size (coarse — like sea salt, not table salt). If you have a grinder at home, set it to its coarsest setting. If you don’t, a lot of grocery store coffee aisles will grind a bag to French press (which is correct here) for free.
What doesn’t work: pre-ground espresso fines (too fine, makes muddy cold brew), or any pre-ground supermarket coffee that’s been sitting on a shelf for months (stale beans = flat cold brew, no matter the method).
Storage and serving
Stored in the fridge, the concentrate lasts two weeks. Past that, the flavor flattens — drinkable but not great. The fix: brew a smaller batch more often. A weekly 1-quart cycle hits the sweet spot for households drinking 1–2 cups a day.
For drinking: dilute 1:1 with water or milk over ice. The bigger the ice cube, the slower the drink waters down — large silicone-mold cubes ($10 once, last forever) are worth it for cold brew specifically. A simple syrup made of 1:1 sugar and hot water (cooled, stored in the fridge) sweetens better than granulated sugar, which doesn’t dissolve in cold liquid.
This is the rare case where the cheaper supermarket coffee performs as well as the boutique bean.
A note on the math
The $350/year figure assumes a 150-day cold brew season (May through September), one large iced coffee a day, with a 50/50 prior split between coffee-shop iced and grocery cold-brew concentrate. Year-round cold brew drinkers see proportionally more savings — closer to $850 if you genuinely drink it every day from a coffee shop. Drinkers who only had a couple a week see less; the proportion is what matters.
For the full hot-coffee version of this argument see the coffee-at-home piece, which covers the equipment payback for daily lattes.
Your cold brew math
You save $187/year