We looked at nine cold-brew coffee makers, analyzed dozens of at-home brewing methods and recipes, made concentrate for more than 200 cups of coffee, and served samples to a tasting panel that included expert baristas. And after all our testing, we found that the Filtron Cold Water Coffee Concentrate Brewer offers the best way to make smooth, delicious iced coffee at home. It’s easy to use and not unattractive (although tall when set up), and in our tests it made cold coffee with balanced acidity, a stronger aroma, and a cleaner finish. Another plus: The Filtron’s cost per cup was the cheapest of all the methods we tested.
If you can’t get the Filtron, we recommend the OXO Good Grips Cold Brew Coffee Maker. The OXO model loads up quickly and easily, and it looks much better sitting on your counter than any other system we tested. It’s tall when fully set up, but it’s pretty small when packed away. The coffee it produced in our tests was brighter and had a thicker body than any other cold brew we made. This model stacks up neatly for storage and doesn’t require any paper or felt filters to use. Costing just a bit more than the Filtron, the OXO brewer is worth considering if you like its look and want to optimize your kitchen storage.
Although we tested making cold-brew concentrate in a French press—and enjoyed some of the results—buying a French press just for this job is not worth it. More on that in a bit.
Much as we did for our guides to coffee makers and pour-over coffee gear, we looked at both preparation and final product to determine the best cold-brew choice. Two Wirecutter/Sweethome writers, both coffee enthusiasts, experimented with each of the makers and the DIY methods for nearly a month, measuring and averaging out the results from the test gear and most of the at-home recipes you can find in a Google search for cold brew. We hosted a tasting panel with four enthusiasts (including writer Kevin Purdy, blind to his own samples) plus two experienced and opinionated baristas. Rest assured that we did not sway or soften their opinions; one of the panelists, while able to pick a favorite, told us that all our samples had “glaring issues.”
Cold brew makes better iced coffee than refrigerated hot-brewed coffee. When you add hot-brewed coffee to ice, it slowly dilutes, resulting in a weaker-tasting beverage. Cold brew, which generally starts from a concentrate, is meant to be watered down, so adding ice, milk/cream, and not too much water provides a stronger, more flavorful drink. Additionally, hot-brewed coffee over ice can taste bitter (some of those flavors are less noticeable when coffee is hot). Brewing with slow, cold exposure, instead of heat, extracts fewer bitter flavors, so you’ll get a sweeter, milder-tasting coffee that’s better for drinking cold.
Every cold-brew coffee method works the same way: Start with a lot of ground coffee (more than you’d typically use to brew drip coffee), add water, let the mixture sit between eight and 24 hours, and then filter it. What’s left is either ready to drink or, more often, a concentrate that you should dilute with water or milk.
We began our research with Cook’s Illustrated, which published its cold-brew coffee maker guide (subscription required) in July 2015. That guide’s results gave us a number of models to start considering, as well as some dismissals. We then turned to comparable reviews, including 2010 and 2012 guides from The Wall Street Journal, plus one from Stumptown Coffee Roasters.
We used these guides and reviews to choose three dedicated cold-brew coffee makers to test. The Filtron Cold Water Coffee Concentrate Brewer and the Toddy T2N Cold Brew System were obvious choices, as they alternated wins in pretty much every guide and review we found. We also included the OXO Good Grips Cold Brew Coffee Maker. As it’s a newer device, it isn’t included in existing reviews; OXO’s products often impress us, however, and the company makes our favorite hot coffee maker, so we thought including this model was important.
For comparison’s sake, we also tested two other hands-on methods. One of our writers has used the CoffeeSock in the past, and a French press is a multitasker that can work for hot and cold coffee. Both make concentrate like the rest of the models we tested.
Testing for ease of use, we followed the provided instructions, noting any inconsistencies or complexities as well as how painful each system was to clean. We ran these tests with Trader Joe’s Kenya AA Coffee―a well-liked, reasonably priced coffee. Brewed hot, this coffee has a sour bitterness without sweet or floral notes. As a cold brew, though, it tastes much better, with reduced acidity and a mellow but preferable mix of tannic and chocolate flavors.
Our next step was a tasting panel. For this round we switched to an upscale bean—Joe Bean Mexico Chiapas—and brewed a fresh batch with each system. We invited six people, including coffee professionals, coffee enthusiasts/nerds, and casual cold-brew drinkers. Tipico Coffee’s Jesse Crouse and Public Espresso + Coffee’s Clinton Hodnett brought their expertise, balanced out by other panelists who used fewer coffee-industry terms but knew what they liked. For this initial test, we followed each brew method’s included instructions, which varied in the ratio of water to bean.
We presented the panelists with six cups of cold brew (one of them made with Trader Joe’s coffee in a French press, for comparison), one after another in a blind taste test. The panelists ranked the cups on a 1-to-10 scale for taste, acidity, and body. The latter two measures were quantitative (as in, how acidic), rather than qualitative (as in, how much they liked the acidity). The tasters had water available for palate cleansing, and we left the cups so that they could compare them directly at the end with additional tastes if necessary. We didn’t serve any with ice, so as to avoid dilution. We asked the testers to note which one was their favorite, and why, after they tasted all six cups.
Later, we conducted a second round of taste testing on our top three models (the Filtron, OXO, and Toddy). We used medium-roast grocery-store beans (Wegmans) roasted one week before and a consistent coffee-to-water ratio (4.5-to-1) averaged from all three brewers’ instructions. We skipped paper filters, broke the surface of each batch with a spoon to wet the topmost grounds, and then let them brew for 24 hours each. We diluted the concentrate 4-to-1 and served it in blind samples to three testers. Based on their feedback, we then diluted 3-to-1 and had a coworker serve us blind samples. This round’s results matched our original testing panel’s findings quite closely. Whether it’s the filters or the water dripping method, these brewers, not their recipes, make different cold-brewed coffee.
The Filtron Cold Water Coffee Concentrate Brewer consistently produced better-tasting coffee concentrate in all our tests, with our tasting panel preferring its brew the most. Compared with nearly every other model we tested, it’s far less fussy to set up and empty. The resulting concentrate costs less per cup than that of any other maker we tried (if you use the default recipe). It’s the choice home cold-brew maker of Blue Bottle and Stumptown, as well as many other craft-minded coffee shops. And although the Filtron doesn’t look as stylish or pack away as neatly as our other picks, its black plastic is less likely to show coffee stains over time than the white Toddy or the clear-plastic OXO.
The Filtron produced a smooth, mellow cup of coffee every time we brewed with it, using beans from Trader Joe’s and grocery chain Wegmans, as well as from local small-batch roastery Joe Bean (roasted three days before brewing). Five of the six tasters on our panel gave the Filtron cup their highest rating for flavor, and three named it their favorite overall. “Major aroma, yet oddly light color,” wrote one barista on the panel. “Mild body, flavor, acidity.” That sentiment was echoed by the other barista, who noted that a “mild body gives way to well-balanced sweetness and acidity.” Another panelist wrote, “Best nose so far, very clean,” going on to say that it “finishes the best so far.” Two separate panelists noted the caramel flavors. The Filtron received almost no dings for acidity, strength or weakness, or body. Only one barista (who generally disliked the lot) found it to have a “short, ashy aftertaste.”
Next to the popular Toddy system, which calls for timed additions of weighted water and coffee, or the Coffee Sock or French press methods, the Filtron system is far easier to set up and empty out. A felt filter and a rubber stopper fit into the bottom of a black plastic bucket with a handle, and an optional (but recommended) paper filter holds the grounds and water. You let your mixture sit for 12 to 24 hours (we brewed for a full day) in the plastic, after which you put the included carafe underneath it and pull the stopper, leaving it to drain about 30 minutes. Cleaning it means either plucking out a filter full of grounds or scooping and rinsing the bucket. After rinsing the felt filter, you store it in water in an included container in the fridge (to prevent mold). The Filtron system makes 32 ounces of concentrate, which you then dilute with water at a ratio of 6-to-1. That’s enough for about 37 6-ounce servings of cold-brew coffee. The concentrate holds for two weeks in the fridge.
Using the Filtron to make cold-brew coffee, with the ratios its maker recommends, produced the lowest-cost coffee of any method we tested. Coarsely grinding 1 pound of $10-per-pound coffee produces 32 6-ounce servings of ready-to-drink coffee, at 27¢ per serving. The Toddy method produces 48 servings at 31¢ per serving, and the OXO model makes 24 servings at 45¢ each. It’s a few cents, but the savings grow as you use fresher, more expensive coffee over multiple batches.
The Filtron doesn’t look stylish, but it doesn’t look bad, either. It is large, standing 19 inches when set up to drip into the carafe. But it stows pretty compactly, taking up the space of a medium-size mixing bowl in a cupboard. You won’t have to treat the Filtron carafe as gently as the glass containers of other brewers, and the black plastic won’t discolor with long-term coffee exposure, as with other models. It is more susceptible to being knocked over because of the narrow carafe it rests on, but that’s relatively unlikely.
For a few dollars more than the Filtron, the OXO Good Grips Cold Brew Coffee Maker is a solid alternative with a few drawbacks. Overall it’s the best-looking unit we tried, and it has the most thoughtful features, but in our tests its coffee’s rich flavor was polarizing.
While the Filtron is functional but not pretty, the OXO is something we wouldn’t mind leaving out on a counter. It’s a little shorter than the Filtron when set up, standing 15 inches tall. It uses a similar reservoir-and-vessel system, but instead of resting directly on top of the carafe, the reservoir sits on a dedicated wide-base stand. The water pours through a perforated lid that distributes the liquid evenly and allows fresher coffee to “bloom.” When the time to drain the concentrate rolls around, you simply flip a switch, avoiding the slight mess on your fingers from pulling a cork. You can even flip the switch back up midstream to pause and to pour yourself some concentrate before it’s fully drained.
Using the same beans as the other tested makers, the OXO produced the most flavorful cup of cold-brew coffee. This is a result of the OXO’s suggested recipe and ratio: 10 ounces of beans to make 24 ounces of concentrate, yielding 10 6-ounce cups of iced coffee, watered down at a ratio of 2.5-to-1. But the OXO also produced more flavorful coffee when we tested it against the Filtron and Toddy brewers using a standard 4.5-to-1 recipe. The metal mesh filter seems to bring forth a bigger flavor.
Whether our panel actually liked that increased flavor is a different story. Two panelists deemed it their favorite, while our coffee professionals were unimpressed. The barista who found all the cold brews to be wrong in some way determined that the OXO brew’s flavor was the strongest. The OXO rated the highest in detected acidity among panelists. The testers also found it to be “vegetal and earthy,” “much stronger,” and “kinda strong for a hot day,” and to have a “bigger body.” One panelist said the OXO brew was “tripping [them] out,” because they tasted florals in a cup that was “relatively low on the acidity scale.” Evaluating coffee is, of course, a subjective thing, but the OXO model seemed to create a brew that was more “punchy” than the mellow, smooth Filtron brew.
We did experience one snag in brewing with the OXO unit. It is sold with a handful of optional paper filters, which you can use in addition above the reusable mesh filter. The company says these filters aren’t required but can help to create a smoother brew with less silt at the bottom. In our tests with the paper filter in place, however, this cold-brew coffee maker didn’t drain properly: It almost immediately slowed to a drip, and we got only a few ounces of concentrate because a silty mudflat of grounds covering the paper blocked its flow. An OXO representative confirmed a slower drain time with the paper filter in place but said he had never seen the stream completely stop as it did in our tests.
You can make good iced coffee in a French press, whether concentrated or ready to drink, but you have to work to get to the right recipe for your particular press, and the resulting brew will have more sediment unless you take the extra step of filtering. Cleaning up is trickier, too, as you must disassemble the mesh filter for thorough cleaning.
We averaged recipes from The Coffee Compass, The Kitchn, America’s Test Kitchen, and a local coffee-shop owner, among others, to make concentrate in a 34-ounce Bodum French press. On our first batch, using Trader Joe’s beans, it produced the most body and the strongest flavor among the brewers we tested. On our second batch, made using the same proportions but with upscale Joe Bean coffee, the French press received the worst rating from our tasting panel, earning a mere 3.5 out of 10 in every category. Panelists said the brew tasted “bland” with “tea-like under-extraction,” and that it was like “cold diner coffee.”
If you already have a French press, there’s no reason you can’t try a few test batches: Start with a 4.5-to-1 ratio of water to coffee, by weight, and filter it if you can through paper or cheesecloth. Then dilute to taste. If you’re a regular cold-brew drinker, though, a dedicated brewer is a better option because it makes more concentrate, it offers easier cleanup, and it has a straightforward recipe specifically designed for it.
The Toddy T2N Cold Brew System is similar to the Filtron in appearance, operation, and resulting coffee, but a little less appealing in each way. The white plastic bucket will take on coffee stains over time, and the glass carafe feels more prone to breaking. The Toddy system’s instructions are more complicated than the Filtron’s, asking for five weighted additions of water and coffee, with a five-minute wait before the final water, and then a light press with a spoon to wet the top of the floating grounds. The Toddy produces 48 ounces of concentrate, enough for 24 6-ounce cups. The coffee that it made in our tests was not bad, just not as flavorful as that of the Filtron, or as full in body as that of the OXO. We can sum up the comments from our panel as “nothing to write home about.” Even when we tested with a standard recipe, testers deemed the Toddy’s brew to be weaker and less interesting than that of the Filtron or OXO brewers.
A Coffee Sock seems to offer an easy way to make iced coffee, but the cleanup is messier than you might anticipate, and the coffee in our tests was unimpressive. It averaged a 5.5 out of 10 in flavor and received the second-lowest rating for body, a mark of 4.3 out of 10. Depending on the size you buy and the container you put it in, the Coffee Sock makes a bit less than 32 or 64 ounces of concentrate, with no specified dilution. We tasted and adjusted to arrive at a ratio of 2-to-1. Tasters said its brew had “not much aroma,” and “less acid, but it suffers for it.” Having to empty the sock of grounds, and then turn it inside out and rinse off the stickiest granules, is not worth the effort with those kinds of results.
The Cold Bruer Drip Coffee Maker B1 earned a “recommended with reservations” tag from Cook’s Illustrated. It’s the most expensive system we researched (about twice the price of our picks), and it makes only 20 ounces of drinkable cold brew (not concentrate) at a time.
We were curious about BodyBrew’s BOD, but it wasn’t shipping at the time we were compiling this guide. We may consider it for a future update.
We skipped the Hario Mizudashi Cold Brew Coffee Pot, the Primula Cold Brew Glass Carafe Iced Coffee Maker, and the Takeya Cold Brew Iced Coffee Maker based on Cook’s Illustrated’s “not recommended” tag. The testers there found that these taller makers tended to make more-watery cold-brew coffee.
Originally published: June 1, 2016