Cold-brew coffee maker

One of the most delicious cups of coffee I ever had was cold-brewed -- the coffee flavor slowly diffused into cold water. No bitter, acid taste, just sweet and aromatic awesomeness. I have no idea if Hammacher Schlemmer's cold-brewer makes a decent cup of joe, but you get the idea.
The hourglass does not require any electricity; simply combine 2 1/4 cups of coarsely ground coffee beans with 3 1/2 cups of water in the brewing chamber and allow the coffee to infuse with the water for 12 to 24 hours. When the infusion process is complete, turn the hourglass over and 16 oz. of extract instantly drains through a reusable stainless steel filter and into the extract chamber. Combine some of the extract with hot water for traditional coffee or cold water for iced coffee. The extract can be kept in the included carafe and stored in a refrigerator for up to two weeks.
So, I don't know about that two week business. All those aromatics are, by definition, volatile. Calling food chemists -- that can't be right, can it?

The Acid Reducing Flavor Enhancing Coffee Hourglass. (via Red Ferret)


  1. If the decanter is properly sealed, then it should keep.

    I don’t drink much coffee, but brewing a little takes as much prep and clean-up as a full pot. I’ve therefore gotten in the habit of brewing a full pot of coffee (using Starbuck’s beans in a much more mundane Mr. Coffee), drinking two cups, and pouring the rest into Mason jars. I stow them in the fridge, and, at random intervals over the next week or two, I’ll microwave myself a cup.

    Even two weeks later, it still tastes fresh to me.

  2. Cold brew is a pretty common menu item in Portland, OR. Most shops use some version of the toddy brewer(non-affiliated). Whatever you use to make it, the stuff keeps for, yeah, almost two weeks in the fridge. When mixed with a diluting liquid, it makes great hot or cold coffee/lattes.

    -rob in portland

  3. My mother *swears* by an apparatus much like this contraption. It really does produce a cup of coffee which is qualitatively different from anything you’ll find hot-brewed like tea, and I always love going back home to have some.

    I don’t know about the two-week rule (since carafes seldom last more than a few days), although the coffee my mother makes is usually kept in a carafe with a vacuum seal, which probably goes a long way to protecting flavor.

  4. It’s not so much that the aromatics will evaporate over two weeks, as the reduced temperature will knock that effect down pretty sharply, however, the aromatics *are* pretty likely to oxidize or otherwise react if stored improperly or made with less than ideal water.

    My favorite is to make ice cubes with the extract, so my iced coffee gets stronger the longer it sits.

  5. I know that a cup of hot coffee will “go off” a bit in under half an hour, but this is hot coffee, so that may merely be evaporation of aromatics as well as oxidation.

    I would be stalwartly opposed to drinking 2-week old coffee, though, even if it was refrigerated.

    More importantly: After that long, even refrigerated coffee might have the beginnings of a mold colony, I would think, especially since it was cold brewed.

    Still, the idea is sure neat, and I bet it wouldn’t be hard at all to try cold-brewed coffee at home without a dedicated gadget, even for the sort of person who could burn water in the kitchen if left alone. Can anyone please recommend their method?

  6. I don’t want to spam my videos, but I put an instructional video on YouTube for cold brew coffee about a week ago. The easiest method, if you have two pitchers, is to put your coffee grounds in a pitcher, add cold water, and put it in the fridge for about twelve hours. Then strain it into a second pitcher. If you don’t have a second pitcher, you can use an internal filter such as cheesecloth.


  7. I have a cold brew system and I’ve left coffee in the carafe for the two week maximum without noticing any decay in flavor. It does produce consistently less bitter coffee and some people don’t like that, considering it a loss in flavor, but that’s not a question of letting it sit.

    A lot of my friends have used it to make iced coffee and they all seem generally pleased with it, no matter how long it’s been sitting. The way it lasts seems odd to me as well, but as far as I’m concerned that claim is true.

  8. I like my coffee bitter and I don’t like waiting for a day either!

    On a side note, me and my partner ordered iced coffee while in the US. In New Zealand an iced coffee is made with milk, sugar, ice-cubes and a bit blob of whipped cream on top with cinnamon or chocolate grated on the top. In the US is was a big cup of cold coffee. My partner threw his in the bin. That was a bit of a culture shock!

  9. @6:

    absolutely, and for 79.95 – darn those marketing weasels and their cognitive blind spots , bitter is what coffee is.

    tho, rly, for iced coffee, just coffee + ice cubes is the best.

  10. Cold brewed coffee needs not an $80 hourglass to make (though it sure looks nifty) Just put the same proportions of grounds & water into a sealed tupperware container and strain it with a fine mesh strainer when the 12 hours are up. I wouldn’t say it’ll keep for 2 weeks in the fridge but certainly would for 1. What makes coffee aromatics dissipate after brewing is the fact that it’s kept at a hot temperature (and indeed starts at a hot temperature). Starting it cold and keeping it cold extends the shelf live drastically.

    Cold brewing does cut the acid of brewed coffee, but it’s worth noting that acid isn’t necessarily a bad thing! What’s more refreshing on a hot summer’s day: a cup of milk, or a cup of lemonaide?

    Also @ #7: Properly brewed coffee isn’t bitter. Intense, acidic, and mildly tannic, yes, but the bitter only comes out when the brew is overextracted.

  11. You can get iced coffee in the states with milk, sugar, and flavoring… it’s just called something else, or you have to ask for the cream, sugar and flavoring.

    I have the Toddy cold brew system which I bought from Amazon for about $32. There are a lot of instructions online for making it without specialized machinery, using easy-to-make apparatus. After a few months of saying “I should try this sometime” I realized I would never get around to trying the DIY methods, so I might as well just try out the cheapest specialty design. I’ve been really happy with it so far.

  12. If it’s worth doing, it’s worth doing ghetto.

    3-to-1 ratio of water to extremely coarse ground coffee in a water bottle in the fridge overnight tonight. I’ll see if I bolloxed it up tomorrow.

  13. it’s cute and inventive, but as soon as i saw it, i instantly thought of my french press doing the exact same thing, but with the benefit of being smaller and having multiple uses, and at a fraction of the cost.

    bitter isn’t ALL coffee is. Granted, it’s part of it, but good joe should have much more to offer. I’m in love with the more subtle flavors i get out of even cheap coffee grounds with my french press, and my old-fashioned percolator does wonders with a larger batch for entertaining company. I’ve never regretted either purchase for a second.

    i’d never thought about cold-brewing coffee, but i’m excited by the notion. i’m looking forward to giving it a whirl!

  14. AIrpillo, you can strain it using your regular coffeemaker’s filter into the unheated pot, then pour it right back into the bottle. If you can find a glass milk bottle they’re ideal.

  15. So, I don’t know about that two week business. All those aromatics are, by definition, volatile. Calling food chemists — that can’t be right, can it?

    Well, as you’re asking for chemical pedantry; no, aromatic compounds are not necessarily volatile.

    If oxidation is the main mechanism for loss of flavour (as suggested above), then flavour should last longer in solution than in solid grounds. Easy to test- compare stored coffee with fresh coffee from stored grounds.

    I recently found some coffee beans that had been stored in a glass jar since the mid 1970s- the coffee they produced was pretty flavourless (rather ‘cardboardy’), but seemed to have similar caffeine content to fresh coffee.

  16. OK, so how does this work if you’re hankering for a cup of Turkish coffee?

    Seriously, a variant of this is the best way to make iced tea:
    Take a glass pot, some not-hot water, add some robust tea, and leave it in the sun while you’re at work or even better, off to Parlee Beach for the afternoon.

    My ratios:
    3l water
    12 tea bags of King Cole
    125 ml sugar (that’s less than 1tbsp per cup),
    the juice of one lemon.

  17. awesome! now i can throw out my 2 taco bell cups!

    as for the two weeks part…i’ll be damned if i ever had it last more than 2 days!

  18. This is pretty much the same deal as the Toddy coffeemaker, which is nothing more than a big jug you fill with water and coffeegrounds and brew like Sun Tea in your fridge overnight, then filter. In other words, if you want the same effect, just mix some coffeegrounds and water, sit overnight, and pour through cheesecloth.

    It keeps for about two weeks, yes.

    And no, hot coffee poured over icecubes is a terrible way to make iced coffee. What that makes is warm coffee-water.

  19. In Japan, a stand making cold brew coffee* is standard in most old-style, low-volume, coffee shops. As a tourist or gaijin all you have to do is ask the master of Kissa/coffee shop to explain the process and more often than not the owner will give you a demitasse cup of it for free (even though it normally costs twice the price of regular coffee).

    The Japanese often call it “Dutch Coffee” rather than “mizudashi coffee.”

    *水出しコーヒー mizudashi kohi(literally “Water Drip”)

    Refer to Japanese photoset:

  20. I’ve been doing this for several years now, without buying the $80 gadget, ever since I stumbled across the recipe somewhere online. I use a bowl and a small strainer, and the only thing I purchased was cheesecloth. I hadn’t thought about using my French press pot, but that would actually work well, too, and be less messy. (Thanks for the tip, 13tales, and yes, we do have French press pots in the US — you can even get them at Target, which means they’re everywhere.)

    The recipe I have calls for starting with cold water, btw. I’ve experimented with the proportion of coffee to water. I like very strong coffee, but not everyone does.

    Regular coffee poured over ice is nasty. I only get iced coffee out at places — like Austin’s wonderful Ruta Maya coffeehouse — that use the cold brew method.

  21. I started doing this DIY this summer using regular coffee filters, a jug, and a strainer. It makes a coffee concentrate that needs to be dilluted with either hot water or cold water/milk to make something drinkable. I find mixing it with hot water is a pain, but it is perfect and makes iced coffee as good as any coffee shop’s I’ve ever tasted.

    1. Well I guess this is 16oz of concentrate that you mix with water or milk to make a drink, so maybe it is not so bad

  22. PaulR:

    I don’t recommend making “sun tea” or cold-brewed iced tea using normal tea. That is just begging for disease and mold in your system. The best thing you can do with tea leaves imported…or even picked locally, is to put them in boiling water or at least very hot water. One of my friends worked at large well known tea bag company in the US – they would process and bag tea sent from China in massive burlap bags…bags full of all kinds of bugs, worms, mold, etc. Because tea is so delicate, the processing of the tea leaves themselves does NOT include sterilizing them. They do clean and sort them, but any bacteria, mold, bug excrement, etc can still be on the tea.

  23. Cold brewed coffee is my favorite summer drink for many years now. Since it takes quite some time I always make enough to last me for two weeks – at least. I didn’t notice any loss in flavor.
    Although I am sucker for gadgets, this is one I am certainly not going to buy. I do it in my french press (which would otherwise sit unused in the cupboard anyway – after a couple years of constant use I grew to hate the somewhat muddy taste) and filter it through a regular paper filter afterwards. This faster and considerably cheaper.

  24. I’ve been using the simple 2-cups method from
    * get two large plastic soft drink cups (I use 44 oz),
    * punch a bunch of small holes in the bottom of one cup (I used a thumbtack),
    *cut a hole in a sheet of cardboard that a cup will fit into with perhaps 2-3 inches below the cardboard,
    *nest the cups (perforated one inside)
    *add coffee & water
    *allow to stand (counter or fridge)
    *when done steeping, lift the inner cup, put it through the hole in the cardboard & set it on top of the original cup to drain
    *When it’s drained, pour into a container.

    I get a bit under a liter out of this, which goes into a repurposed 1-liter water bottle for the time being.

    If you’re going to be sweetening, it’s also worth making sugar syrup in advance – 2 cups sugar, 1 cup water, low heat on stove, continue heating & stirring occasionally for about 5 minutes after fully dissolved, pour into a container. If using a plastic container, let it cool enough to not melt your container.

  25. Repeated BoingBoing friend and coffee guru Tonx drinks and enjoys cold brew coffee, so it can’t be all bad.

    Actually, it’s spectacular. It’s fast to make in the morning (especially in summer when I want it cold), tasty, and full of flavor. The flavors you tend to get do differ from regular hot coffee, but are quite pleasant.

    Strangely, I’ve never been one to pick a coffee and stick with it — but for coldbrew I’ve settled on a favorite, Stumptown’s Holler Mountain Blend.

  26. It seems like there’s some confusion: iced coffee != cold brewed coffee.

    Iced coffee is usually hot brewed and then chilled. Cold brewed is made with cold water.

    IMO, bitter and acidic are two unfairly maligned flavors. A little bit of each is a huge part of what makes coffee so damn good.

  27. I bought the Toddy cold brew maker after doing a couple of batches ghetto. I found the filtering process for a whole pound of coarse-ground beans to be agonizingly slow and awkward using items I happened to have in my kitchen (fine mesh strainer, conical paper filter, pitchers). Once I decided that I wanted to drink it on a frequent basis, I figured I’d give ToddyCorp their absurd markup on some molded plastic, felt discs, a rubber cork and a cheap carafe. I haven’t regretted it, and it makes more coffee than the Hammacher Shlemmacher thing does for less than half the price (though it’s not as purty).

    I don’t much care for cold brew as a hot drink, but I think it rocks when iced, about half-and-half with whole milk and sweetened with simple syrup (sweetening it with granulated sugar is an exercise in futility, just as with any other cold drink).

    I don’t know about two weeks, but the stuff holds up fine over the course of a week in my fridge.

  28. I worked for True Brew Coffee in New Orleans around 1990. They used the Toddy method for all iced coffee brews. I don’t know that this particular method is exactly like the Toddy method, but it seems awfully close.

    I do find that the Toddy method leaves a distinctive flavor in the coffee. It’s not my cup of … er… coffee.

  29. I’m probably repeating someone, but to save money and space, just use a french press, or a tupperware container. Leave it in the refrigerator with grounds and cold water for 12 hours.

    After two or three days I do notice a difference in taste. Why not just make a new batch every night? It doesn’t take that long.

  30. I’m a huge fan of cold-brewed coffee, but you don’t need any expensive or bulky contraptions to do it. Just put the coffee and water in a pitcher, let it sit overnight, and filter it through a strainer in the morning. I make a batch every couple of weeks, and it does keep just fine in a sealed container in the fridge. And it’s delicious with cold milk!

  31. Once you go Toddy — sorry — we’ve been using ours for years. Love the flavor, makes hot or amazing cold coffee, and keeps for over a week, refrigerated. YMMV, of course.

  32. @ #28 posted by Anonymous – you dilute the coffee. The toddy system I have uses a pound of coffee, and you get around 8 cups of concentrate. Lasts my roommate and I (who drink at least 1 cup each morning) a week. Friends who drink regular drip coffee say they go through about a pound a week as well. So it’s not a waste.

  33. I cold brew using a french press.

    -1 cup ground coffee
    -Fill press up with cold water while stirring
    -Cover and let sit in fridge overnight
    -Carefully/slowly press down plunger to minimize grounds getting through filter
    -Put coffee in resealable container and store in fridge for iced coffee usage!

    So easy and so good!

  34. I bought this and have used it for about a month. The idea that I could store the “extract” for a week was appealing, instead of using the french press every day. This thing doesn’t make coffee, it makes coffee “extract”, which is like a concentrate. Only, using their recipes to water it down taste… off. I tend to use a lot more extract than their recipes say to, and I still don’t feel like I’m getting much caffeine. And did I mention it always tastes off? I haven’t changed the type of beans I use. I don’t know. I think it’s an interesting concept, but it doesn’t work for me :(

  35. I’m surprised no one has mentioned “coffee milk”. Add an aliquot of the cold-brewed coffee concentrate to whole milk, preferably not skim. Add sugar or sugar syrup to taste. Ghirardelli chocolate syryp is good, too, or any other proper dutched cocoa/sucrose mixture. Serve in a solid silver julep cup. Mmmm.

  36. Went into the kitchen this afternoon, emptied the stuff through a filter, and diluted some of it in milk for a treat. It’s definitely quite tasty, even with my atrociously improvisational approach.

    I have a sneaking suspicion as I drink it that it’s going to have one hell of a strong caffeine content, though. Delicious treat now, then manic action, then a headache and remorse, woo! It’ll be sort of like being a borderline alcoholic all over again =P

  37. A quick internet search turns up many ways to make cold brew coffee in a glass container, such as a mason jar. There is no need for this $79.00 plastic abomination.

  38. Anonymous @ 29:

    Well, the ‘recipe’ for Sun Tea was given to me by a biologist… She didn’t seem to think the contamination would be a problem.

    Haven’t you ever eaten wil blueberries, raw, that you’ve I’ve come across while hiking? Haven’t you ever chewed a chunk of pine sap, fresh off a tree, to make gum (THAT’S bug, excrement, bacteria, mold, and lichen infected stuff!)?

    As with shower heads, if your immune system is still working, it shouldn’t be a problem, IMHO.

  39. While I love a swanky container, really, all you need for cold brewed coffee (if you don’t have a french press) is a pitcher.

    I usually make a big pitcher of it, and then, 12-24 hrs later, I pour it through a coffee liner lined mesh strainer into a bowl. Rinse the pitcher out, and add back the strained coffee, and voila.

    I’d love to get a french press, but for now, my cheapo rubbermaid plastic pitcher works just dandy.

  40. #6:

    More importantly: After that long, even refrigerated coffee might have the beginnings of a mold colony, I would think, especially since it was cold brewed.

    Coffee contains phenols, guaiacol and creosol, which makes it antiseptic. A cup of coffee won’t mold unless you add milk or pollute it in some way.

  41. I didn’t know that! Thanks for the correction. I guess I only ever have seen mold on coffee with milk added.

    That might also explain why it’s necessary to use extracted and rinsed coffee grounds when using them as a mycological substrate (I’m fond of oyster mushrooms grown on discarded coffee grounds. Food from trash.)

  42. I’m a coffee connoisseur, and have tried both the Toddy Cold Brew System, and the Hourglass Coffee Maker. Personally I like the Toddy Cold Brew System much better. It is much more user friendly and so much easier to clean. The simplicity of the system just makes sense.

  43. Well, another convert here! I made cold brew coffee in my french press overnight, and today, really for the first time ever, I’m able and delighted to drink coffee black! I am a lover of coffee, and drink several cups a day, but when you add up the amount of cream and milk I was using with the usual hot brewed stuff, it makes for a hefty caloric load. Not so with cold brew. I wouldn’t dream of covering up the taste and aroma of excellent coffee with additives ever again.

  44. I think alot of you aremissing the idea of cold-brew. It is to cut down on the acidity, making the coffee more healthy. Do to diane sobos’ web site, for the idea ehind lower acid levels.

  45. Things that can add odd flavors to coffee: tap water, plastic, paper filters. To achieve purity for flavor and health, use only glass or stainless steel equipment. Some plastics can not only add strange flavors, but also toxic chemicals like Bisphenyl-A (BPA).

    I’m using bottled water (no chlorine, flouride, etc.) and storing the extract in a clean wine bottle with one of those rubber stoppers with accompanying pump to extract air from the bottle. For how frequent and how much I enjoy coffee, the extra effort for quality and purity is worth it!

  46. #28 • 7:11 AM, Sep 15 • Reply
    WTF? 2 1/2 CUPS of ground coffee for 16 ounces of liquid? What an outrageous waste of coffee.”

    It is then added to warm milk for a cafe late, hot water for an American, or any mixture you normally like.

    Heat a 3/4’s full cup of water in the microwave, add 1/4 cup the concentrate you just made, bob is your uncle.

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