Complete Guide to Making Cold Brew Coffee at Home

Cold brew coffee has experienced a renaissance in the last few years. Perhaps you’ve tried it at your local coffee stand, but did you know that it is easy and inexpensive to make yourself at home? In this guide I will show you everything you need to know to brew delicious cold brew coffee at home.

As the name suggests, cold brew coffee is coffee brewed without hot water. The temperature of the water does not need to be cold–it can be anywhere from cold to room temperature.

Cold brew coffee can be made using immersion or drip techniques. They both have their pros and cons, but one main thing that they do share in common is they both take time.

The advantages of the immersion technique are it is simple and uses equipment you probably already own. You can start today. The disadvantage is it takes longer to brew coffee this way.

The advantages of the drip technique are a smoother brew (in my opinion) and it takes less time to make. The disadvantage is you do need a special brewer to do this.

How to Make Cold Brew By Immersion

Immersion is a popular and simple technique for making cold brew at home because it doesn’t really require any special equipment. Most of what you need you probably already own .

With the immersion technique you simply soak coffee grounds in water for several hours and then strain out the grounds.

Depending on how much coffee you used relative to water, your end result can be a concentrate which you can dilute to taste with more water, or something that’s near ready to drink perhaps requiring just a slight dilution and or the addition of some ice.

Basic Technique:

  1. Measure out coffee grounds into a container
  2. Add water
  3. Let steep for 12 to 24 hours on a counter top or in the fridge (I recommend the fridge for reasons I’ll discuss later )
  4. Pour the coffee and grounds through a filter and recycle,compost, or discard your coffee grounds
  5. Enjoy your homemade cold brew

That’s the basic how-to, but let’s explore the details for brewing your perfect cup.

What Ratio of Coffee to Water to Use

The first question most people have when they start to brew their own cold brew coffee is how much coffee they should use?

The perfect ratio is the subject of much debate in coffee forums. Part of the answer will depend if your aim is to make a concentrate that you can later dilute or a ready to drink cup.

For a concentrated brew, use one part coffee to 2 parts water . So for example, 1 cup of coffee grounds and 2 cups of water.

Now for those of you used to brewing hot coffee that’s a heck of a lot of coffee grounds, but this ratio yields a concentrate that can be diluted approximately 50% with water. So in effect this produces 3-4 cups of finished cold brew depending on how strong you like it.

If you like your coffee strong, I suggest making a concentrate like this since it gives you the freedom to dilute to your taste. Try being stingy with the coffee and you may end up with a weak, insipid brew.

If you prefer to try and brew something closer to ready to drink, try a ratio of two coffee scoops to 1 cup of water.

How long does it take to make cold brew coffee?

Hot water does a great job of extracting coffee flavors from the beans. Anything less than hot water isn’t as efficient. We compensate for this by soaking the grounds for longer. This is why cold brew can’t be rushed.

Generally it takes between 12 to 24 hours to make a good cup of cold brew coffee. Many commercial cold brew manufacturers brew for between 16 to 20 hours. I have made palatable cold brew in as little as 7 hours, basically getting things going before going to bed and straining in the morning.

Should You Brew in the Fridge or on the Counter Top?

You may find several recipes out there advocating steeping cold brew at room temperature. This works but personally I have stopped doing this.

You see, water has this habit of growing things when left to sit. On top of this, coffee is considered a low acid food so it doesn’t have the inbuilt microbial inhibition.

If you brew on the counter top, you will want to make sure that all of your brewing equipment is very clean. I recommend washing it in the dishwasher and let the very hot water sanitize it.

I have started brewing my coffee in the fridge. Keeping the brew in the fridge slows down microbial growth. Of course using clean brewing equipment is still best practice even in the fridge.

When brewing at colder temperatures you may want to brew a little longer to ensure adequate extraction of the coffee .

What kind of coffee should I use when making cold brew?

This is largely a matter of personal preference. Light roasts tend to have a fruitier flavor while dark roasts are a bit smokier in flavor. I tend to choose medium roasts for the best of both worlds!

Coffee beans from Central America are popular among ready to drink cold brew companies. A runner up is Ethiopian coffees. Experiment with a few different varieties and see which you prefer.

The size of grinds can make a difference in your final result. Fine ground coffee such as used for espresso are generally not recommended because it’s easier to get an over extracted, bitter result.

A finer ground coffee has greater surface area in contact with water, maximizing extraction but possibly to the point of over-extracting (causing a more bitter result). Because we are dealing with long extraction times, using a coarse ground coffee produces a better result by decreasing surface area of the grounds.

Many supermarket coffees come in fine or medium grind, so does this mean you need to grind your own beans? Well generally the freshest most flavorful coffee will always come from freshly ground beans but if you don’t want to grind your own you don’t have to.

With the popularity of cold brew several roasters are now selling coarsely ground coffee marketed at cold brew drinkers.

You can read more about choosing beans for cold brew here.

Filtering your cold brew coffee

Once your coffee is done steeping it’s time to filter out the grounds. There are two main options for this:

  1. a coffee filter in a pour over coffee maker or mesh strainer
  2. a coffee bag or sock

For me the coffee filter method is the easiest and cleanest. I use white cone filters as I find the unbleached ones have a slight bit of paper taste to them. 

I use a pour over coffee maker to support the filter and I can pour in some coffee and go do something else while it strains.

When using a coffee sock or bag you you can actually steep your coffee right in the bag. Then when you are ready to filter you just remove the bag and maybe give it a little squeeze to get all the coffee out and you are done. Kind of.

The nice thing about coffee bags is they are eco-friendly and reusable, the not so nice thing is that they can be a bit of a pain to clean with coffee grinds getting stuck in the seams.

It’s important to get them thoroughly clean so that the flavor and safety of your next batch isn’t affected by old coffee grounds.

Read more about using coffee bags here.

Using a French Press for Immersion and Filtration

If you have a French press coffee maker this can be a great way to make cold brew by immersion. You can steep the coffee grounds directly in the French press and when you’re ready to strain push the plunger down.

I like to let the grounds settle just a little bit before pouring as I find a French press does allow some sediment into my finished coffee. Of course the coarser the grind the less of a problem this is.

You can read more about making cold brew in a French press here.

Making Cold Brew with the Drip Method

Cold Drip coffee is the other main method for extracting coffee without heat.  This method does require special equipment, however several new products have hit the market that are affordable.

One advantage of cold drip coffee is you can be drinking coffee in just a few hours. Not exactly instant cold brew, but the next best thing!

Equipment Needed

You may also see the cold drip method referred to as Kyoto or Dutch style coffee. Traditional cold drip towers are elaborate glass and wood affairs that can cost in the hundreds of dollars. You may see these at high end coffee shops.

More practical for the home user are devices like the Dripo (my favorite for small batches) and the Bruer.

Cold Drip Technique

The exact technique for cold drip coffee will vary slightly depending on the brewer you are using.

In general, coffee grounds are placed in the device with a small piece of filter paper over them. Cold water (often with ice) is placed in a container above the grounds and the water drops through drip by drip.

The function of the filter paper is to distribute the drops of water across all of the grounds so that the water doesn’t just drip through the center of the coffee.

While on a daily basis I stick to immersion, I have to say that cold drip coffee is in my opinion superior to immersion coffee. It has a richness that I don’t get with immersion brews.

FAQ

How long can I store my brewed coffee for?

Cold brewed coffee does not contain some of the coffee oils that hot brewed coffee does and therefore does not oxidize or grow rancid as quickly. Personally, I would keep cold brew in the fridge for up to a week. In my house, a batch rarely lasts that long.

Can cold brew coffee be frozen?

Yes! In fact, if you have a little leftover coffee go ahead and make some ice cubes out of them. You can use these in your coffee and it won’t get diluted when the ice melts.  After making your cubes, store them in an airtight container for up to six months for best taste.

Can I heat cold brewed coffee?

Yes, in fact William Ukers, in his exhaustive All About Coffee (1922) describes a British practice of brewing at room temperature overnight, and then very gently heating the strained coffee in the morning. 

My first introduction to cold brew in the 1990’s was when an acquaintance described a similar practice of brewing a cold brew concentrate and then diluting it with boiling water to make a hot cup of coffee. Either way, it can be done. Whether you will enjoy the taste, only you can answer!

How does cold brew differ from iced coffee?

Cold brew is made from cold or room temperature water. It is never heated (unless you want to, see the previous question).

Iced coffee is brewed hot and then cooled. This can be done by refrigerating the coffee, or by immediately pouring it over ice (e.g. iced Americano) or using the Japanese Pour Over Ice Method

The main difference will be one of flavors as hot water extracts certain flavor components from coffee that cold brewing doesn’t. It is these same flavor components that give hot brewed coffee its bitter notes.

Can I make cold brew coffee with whole beans?

I’ll be honest, I have not tried this but you would definitely be limiting the surface area of the coffee in contact with the water.

I have used coarsely chopped coffee beans to make a coffee infused milk and/or cream for some of my recipes (Cold Brew Crème Brulee, Cold Brew Ice Cream) and it worked quite nicely. If you don’t have a coffee grinder, I would at least chop them up a bit before trying this.

Whether you immerse or drip your cold coffee, I think you will agree that brewing it at home can save you a lot of money over buying your cold brew at the coffee stand or in a bottle.

Coffee in a mason jar with ice
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