How To Make Cold Brew Coffee In A Mason Jar – The Easiest Way To Make Cold Brew Coffee At Home

Cold brew coffee is a refreshing, smooth and low-acidic alternative to traditional hot coffee, and making it at home has never been easier! With just a few basic ingredients and tools, you can enjoy the delicious taste of cold brew coffee any time. A Mason jar is the perfect container to make cold brew coffee as it’s easy to find, affordable, and easy to use. In this article, we will walk you through the steps to make the perfect cold brew coffee in a Mason jar.

In this article we’ll show you how to make cold brew coffee at home in a mason jar, and why the method we show you here is the easiest way to make cold brew.

cold brew ready in recipients

What Is Cold Brew Coffee?

Cold brew coffee is a type of coffee that is brewed without heat, by steeping coffee grounds in cold water for an extended period of time, usually 12-24 hours. This process results in a smoother, less bitter and less acidic coffee compared to traditional hot brewing methods. The resulting coffee concentrate can be diluted with water or milk to create a refreshing and smooth iced coffee drink.

Do not confuse cold brew coffee with iced coffee. Iced coffee can be prepared with either cold brew or chilled hot brewed coffee. We have this infographic where we show the differences between cold brew and iced coffee, if you need more info. 

When I go to a coffee shop, I order a cold brew i8ced coffee, so that the barista knows that I want my cold brew coffee iced.

Why Should You Make Cold brew at Home?

There are several benefits to making cold brew coffee at home:

Convenience: Cold brew coffee can be made in advance and stored in the refrigerator, so it’s ready to drink whenever you need it.

Customization: When you make cold brew coffee at home, you can control the strength, flavor, and sweetness of your coffee, making it possible to create a brew that is tailored to your specific preferences.

Cost-effective: Making cold brew coffee at home is often cheaper than buying it from a coffee shop, especially if you make a large batch and store it in the refrigerator.

Quality: Homemade cold brew coffee is often fresher and made with higher quality coffee beans than store-bought coffee, resulting in a better-tasting drink.

Health benefits: Cold brew coffee has a lower acidity level compared to traditional hot-brewed coffee, which can be gentler on the stomach for those who are sensitive to acidic drinks.

Overall, making cold brew coffee at home is a convenient and cost-effective way to enjoy a refreshing and smooth coffee drink.

Why The Mason Jar Method?

Technically, it’s not the mason jar method that you saw before. This method is not using a mesh strainer, or a cheese cloth, which work, but they are messy and inconvenient. You have to clean the mesh strainer and the cloth, they tend to make a mess on your kitchen counter unless you are extremely organized, and they require more handling in general. 

This method uses the mason jar, everybody has one in the kitchen, and disposable cold brew filter bags. You can still use reusable cloth bags, if you want to save a penny, but if you can afford the money for a bag of awesome coffee beans, you can probably “splurge” for 100 disposable bags that will last you a few moths. 

There are some advantages to brewing with a cold brew coffee maker such as the Filtron, or the Toddy, but the mason jar and the disposable filter bag is inches behind, at a better price. The Filtron for instance. is one of the best cold brew makers for filtration. 

This is is the video version of the article. The article has more technical information, for the detail oriented, so we recommend it.

How To Make Cold Brew Coffee at Home in a Mason Jar – Step By Step Recipe

Now that we hopefully convinced you to start making cold brew at home, let see what’s the recipe and how to make it. I promise, this is the easiest and most convenient way of making cold brew, without investing in a coffee maker. 

how to make coffee with a disposable filter bag

Materials and Ingredients

  • Mason jar, it can be any recipient large enough that you can close tightly. Here is a large mason jar if you don’t have one in the house.
  • Coffee beans, or ground coffee – We recommend coffee beans, if you have a coffee grinder, because you will maximize coffee freshness. My favorite beans are a medium roast, and for this article I used Miscela D’Oro Gran Crema, but Grand Aroma, or Gusto Classico are also great choices for a medium roast coffee bean.
  • Filtered water, or spring water. A good tasting water is critical as water is the main ingredient in coffee. Water tastes bad, your coffee cup will taste bad.
  • One or two disposable cold brew coffee filter bags. (they are much more convenient than the cheese cloth, and they filter better). I use these disposable filter bags on Amazon, I tested a few brands and these are some of the ones I liked.

Cold Brew Coffee Recipe and Step by Step Guide

Grind One Cup of Coffee Beans

how to make coffee with a disposable filter bag
Grind one cup of medium roast coffee beans.
  • Use a medium, up to a medium-dark roast, which is the perfect balance between perfect extraction and avoiding roast flavors. More information on this post: “What Is the Best Coffee for Cold Brew?”
  • Grind your coffee beans to a medium coarse grind. You will find a lot of advice saying to use the coarsest on the grinder. In my experience, a medium-coarse will help you extract the coffee better. We have an article in the pipe, where we do the brew/taste research, so you don’t have to. We show in that article what are the pros and cons of using finer grinds.
how to make coffee with a disposable filter bag
This is what everybody else is recommending for cold brew. However, I recommend a medium coarse, something in between drip grind and coarse. So if you want to make great coffee, grind finer than this.

Transfer the Ground Coffee in the Filter Bag

We call it cold brew coffee filter bag, but you can brew hot coffee with it as well. It works as a tea bag. You soak it in water, let it steep and just get the bag out when the coffee is fully steeped.

how to make coffee with a disposable filter bag
Transfer the coffee grounds in the filter bag. The bags we are using are on the smaller side, so we need two of them. I like the bags smaller, because I can use smaller mason jars, without wasting bags.
  • Transfer the ground coffee in the bag, and tie the drawstring carefully, so no grounds can get out into your coffee.

Soak the Coffee

Place the coffee bag in the mason jar, and then pour 5 cups of filtered water over the grounds. This recipe is for a 1.5 quart mason jar. You will have to do the math and adjust your recipe accordingly for a different mason jar size.

how to make coffee with a disposable filter bag
As you can see in the picture, the coffee has already started to extract. The brew is now ready to steep.
  • Pour 5 US cups of water over the coffee bag,
  • Stir occasionally, to make sure the grounds inside the bag are all wet, for an even extraction.
  • Make sure the mason jar is full, you want to leave as little space as possible in the jar, to prevent spoilage.
  • Screw on the mason jar lid, for the same reason

Let It Steep

Steeping is probably on of the most discussed aspects about cold brew. People usually ask what is the perfect steeping time and what is the perfect steeping temperature? There is no right and wrong answer here, and to each their own. But here is how I like to do it, and I will explain why in two steps, a bit now and a bit later in the tutorial.

cold brew coffee steeping in fridge
The beauty with mason jar cold brewing is that the jars can fit nicely in the fridge, and they don’t take much space. O love brewing with a cold brew coffee maker, but it’s rather inconvenient, compare to the mason jar/disposable bag solution.
  • Move the mason jar in the fridge. The fridge is better than room temperature because at colder temperatures you avoid spoilage. However, note that fridge temperature will require you to brew a few hours longer than room temperature.
  • Steep for 36 hours. Longer steeping times give you a stronger brew, with the same amount of caffeine. In other words, when you dilute your cold brew concentrate, you will add a bit more water, to get the perfect taste, but the caffeine level will be the same. In other words, you’ll drink more coffee, without getting jitters. That’s pretty cool in my opinion…

Strain and Decant the Coffee

There is no need to strain, because the grounds are contained in the filter bag. So the straining process is reduced to taking out the filter bag, and put it in the garbage. Isn’t that easy? But let’s get back to our step-by-step.

how to make coffee with a disposable filter bag
I say strain and decant, but really, when you use a good filter bag, there is no need to decant. And the straining is as simple as taking the spent grounds out and dumping them.
  • Remove the filter bag with the spent coffee grounds, an throw it in the compost bin.
  • Leave for another 4-6 hours and decant in another recipient.
    The coffee you get now is a little cloudy, much like espresso, but to a lesser extent. If you don’t like muddy coffee, like French press, or espresso, decant it. Otherwise drink as is. Note that the suspended microparticles will brew a little more in the fridge, so your coffee might get even stronger.

Dilute and Serve

This is a strong coffee. You can’t drink it as is unless you serve it similarly to espresso. Small portions in a demitasse, or as part of a cold brew iced latte, or cappuccino.

how to make coffee with a disposable filter bag
Cold brew is great as is, there is no need to add milk. But you will have to dilute the concentrate with water. Our concentrate is made with 1:5 coffee to water ratio, and brewed for 36 hours. A good starting point is 1:1 coffee concentrate to water. Taste and adjust.
  • Pour in a tall glass for a nice visual effect. 
  • Dilute the result 1 to 1 with spring water, or filtered water, or ice cubes volume equivalent. 
  • Taste it and add either water for a less intense flavor, or more cold brew for a more intense flavor. 
  • Write down how much coffee or water you added, so you can replicate the ratio.
  • Add milk, and flavorings to your taste and serve it. Great flavorings are cocoa, vanilla, coconut cream, or a splash of rum.

Store in the fridge

You can store the rest of the cold brew in the fridge for up to 3 weeks, and even more, if your bottle is properly sealed.

Cold brew doesn’t change its properties as hot brews, so you can store it in the fridge without any problems. I recommend storing it as a concentrate, though and only dilute it when you serve it.

Cold Brew Tips and Tricks

  1. Experiment with coffee to water ratios. If you use the ratio we recommend, that is a 1:4 coffee to water ratio, and up to 1:6, you will get a coffee concentrate. Experiment with this ratio, as some of the soluble solids from the grounds might saturate the brew. So then you coffee will have different flavors.
  2. As a starting point, use this coffee to water ratio and dilution: 1:4 coffee to water during the brewing phase, and steep for 12-16 hours. Dilute the cold brew concentrate in a 1:1 ratio with water. Tweak this to your taste, by adding more cold brew concentrate, or more water, or your favorite creamer.
  3. Measure and write down your perfect dilution ratio, so you can replicate it next time. You noticed probably that in my step-by-step guide the recipe calls for 1 cup of medium-coarse ground coffee and 5 cups of filtered water. This is a ratio of 1:5 for steeping and 1:1 for dilution. That’s because we steep for 36 hours. The longer you steep, the more dilution you need. 
  4. You can play with these ratios of coffee to water: 1:4 to 1:9. Note that 1 to 9 is drinking strength, so you don’t have to dilute it anymore, but this has the disadvantage that it needs more space during brewing. The 1:9 ratio is for longer brew times, a 12 hours steep time will get you a weak cup of coffee. 
  5. Experiment with the brew time, this is where many people get confused. 
    Cold brew coffee doesn’t get over-extracted, it only gets stronger. So if you extend the brew time, you will get a stronger coffee, but with less caffeine. This is my personal preference. I’d rather drink more coffee, and enjoy a jitter free caffeinated beverage. And this is actually better than preparing cold brew with decaf.
  6. If you are in a hurry, you can brew it for 12 hours only, but your coffee cup will be weaker, and many of the great flavors in cold brew will not get extracted.
  7. There is no right or wrong for the brewing temperature. As long as the steeping water is kept above freezing point, but no warmer than room temperature. Just remember that the colder the steeping temperature is, the longer it will take for all soluble solids from coffee to dissolve.
  8. The grind size is another rather misunderstood factor. The common advice you’ll get is to grind coarse. There are two reasons people grind coarse.
    One of the reasons is because it’s easier to filter it. Remember, we are working with large quantities of coffee and filters get clogged when you strain and filter 1 cup of ground coffee. This is not a problem for us, since coffee is contained in the filter bag.
    The other reason is to avoid over-extraction. The logic behind that is that with such a long brew time, coffee is over extracted 
  9. Use decanting rather than filtration, for cold brew. Filtration through a paper filter doesn’t work with large quantities. Decanting takes longer, but it’s way easier than filtering with a paper filter. I personally drink the stuff as is, more like a cold brew espresso, but I know folks that are put off by the muddy stuff, and they like their coffee clear. The paper coffee filter works great when brewing with hot water, because we want that filtered fast, so we can drink our cup hot. You can’t decant drip coffee, but you can decant cold brew.
  10. An alternative to the above solution is to use a paper coffee filter when you drink. So take it out of the fridge, and pour it in the cup using a dripper and a filter. 
  11. Water quality. The best is the spring water, because the mineral balance gives it the perfect taste. Filtered water works too. Just make sure you don’t use bad tasting water. For chlorinated and chloraminated water, just add a pinch of vitamin C, (sodium ascorbate type) in the water at brewing time. 
  12. The best beans are medium to medium dark roast. You can also use ground coffee, although the grind size is a bit too fine. But remember, you can always decant, although decanting takes away from the convenience of this method. The most important thing is to use fresh coffee. Packaged coffee from big companies such as Starbucks, illy, Lavazza are good because they are specially packaged to have a longer shelf life, (vacuum, nitrogen flush, etc.)
  13. Do not try to use very light roasts, as cold water cannot extract them properly. The very light roasts are meant for drip brew, specialty coffee only.
  14. Very dark roasts are also not recommended. When we let the coffee steep for such long times, some of the unwanted roast flavors such as the ashes, are going to be extracted in larger quantity, and your coffee cup will taste like smoke. 
  15. Freeze the cold brew concentrate into coffee ice cubes, and dilute it with water or milk. Make sure you calculate how much coffee you pour in the ice cube tray so you can dilute it properly. The coffee ice cubes trick is really nice, because it keeps your drink strong until the end. 
  16. If you want to extract bolder flavors from your coffee beans, let the cold brew steep for 72 hours. Remember, this will be a stronger coffee that you need to dilute more, but the caffeine content will not change, because that is extracted in the first 12 hours.
  17. If 72 hours seems like a lot, strain the grounds, but leave the sediment in the brew for up to several days before decanting. The sediment can brew just a tiny bit more and it give your cup a bit more flavor.


Making cold brew coffee at home with a mason jar and a disposable coffee bag is the easiest way. You just need the patience to wait for the coffee to brew. You will get a smooth and less acidic cup of coffee, with unique flavors that you won’t get with hot brews. You will save money, make better tasting coffee and avoid the trip to the coffee shop.

If you use our method, please come back for questions, if you have, or just to share your experience, or favorite ratio, or maybe share some tips that I don’t have in my guide. 

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