How To Make Cold Brew Coffee

I’d heard Glen Howerton talk about how much he loves cold brew coffee on the Always Sunny podcast and decided that I wanted to make some for myself.

I did a bit of Googling and found out that the most common variables when it comes to making cold brew coffee are:

  • The coffee to water ratio
  • The grind of the coffee
  • Whether to have the coffee hot or cold

Over the last couple of days, I have tested all these variables to come up with the best possible cold brew coffee recipe.

Cold Brew Coffee Recipe

Before we go through how to make cold brew coffee I need to say that this is a pain in the butt to make without a proper cold brew coffee maker or a French press.

Filtering out the coffee from the grinds takes about 30 mins for a decent-sized cup of coffee, and if you want a clear final drink then you will need to change the filter paper several times for each cup that you make.

This means that you can’t just do something else while the coffee filters out from the grinds.

Although a French press is better than using coffee filters, it doesn’t filter out the water very efficiently. Even with a decent sized French press (mine holds 30 fluid ounces of water – enough for three large servings of regular brewed coffee) I could only make one serving of cold brew.

Ideally you want a proper cold brew coffee maker for this.

Anyway, here is the recipe:

Ingredients:

  • 1 part coffee, as coarsely ground as you can possibly get it
  • 5 parts water

You will also need either:

  • A cold brew coffee maker (recommended)
  • A French press (a decent option)
  • Two glasses large enough to hold the coffee and water and several coffee filters (this way is very fiddly and time consuming)

How to make (without a cold brew coffee maker):

  1. Fill glass with coffee and then pour the water over it.
  2. Put the glass in the fridge for 12 hours
  3. Filter out the coffee with a coffee filter into a second cup

How to make (with a cold brew coffee maker):

  1. Fill the coffee maker with water and fill the built in filter with coffee
  2. Put in the fridge for 12 hours
  3. Pour into cup

How to make (with a French press)

  1. Put the coffee and water in the French press
  2. Put in the fridge for 12 hours
  3. Plunge the French press to the point where the coffee and the water are separated
  4. Pour into cup

Tips For Making Cold Brew Coffee

Although the step-by-step preparation of this is simple, there are some aspects of making cold brew coffee that I found surprising as someone who had never made it before.

These are:

You use a lot more coffee than you’d expect

Coffee to water ratios are measured out in terms of their respective masses.

You’re best off using the metric system (millilitres and grams) as one millilitre of water is one gram. For reference, one cup of water is 240 millilitres, and one fluid ounce is 30 millilitres.

Therefore, for one cup of water, you want to use 48 grams of coffee. That’s about 8 tablespoons. You can see how much space this amount of coffee takes up in a small (one cup serving) mug.

Cup of coffee grounds for cold press coffee
For scale, this glass can hold one cup (240 ml) of liquid.

The filtering took a long time

I found that it was very hit or miss whether I was getting a clear final brew.

For the final coffee to be clear it had to be filtered pretty much drip by drip.

Cold brew coffee being filtered
Like this

As soon as it came out in even a slight trickle I would start getting grinds in my final coffee.

I’d therefore recommend that you change your coffee filter for every half a cup (120 ml) of coffee that you make.

Filtering a whole serving of coffee took about 40 mins.

Therefore if you want to make this type of coffee regularly I would recommend getting a cold brew coffee maker. With a cold brew coffee maker the coffee infuses in the water in a built in, removable filter.

When the cold brew is ready to serve you can just remove the filter and you have the final liquid free of any grounds.

How Did The Cold Brew Coffee Taste?

The coffee tasted strong, however, it did not have the sharp notes that you often get from a strongly brewed black coffee. I usually struggle to drink black coffee but I had no problem drinking this without milk.

If I was offered a choice between cold brew coffee and a regular filter coffee, I would choose the cold brew nine times out of ten.

When you mix it with milk it makes for a particularly smooth drink and is therefore the best brewing method to use for iced coffees.

The one thing that puts me off having this daily is the amount of coffee that you need to use for it.

Even using the cheapest beans I can buy at my local store it would still end up costing 80 cents a cup which for an at-home coffee is a bit too expensive.

I will be having it as a fairly regular treat, however.

What Is The Best Coffee To Water Ratio For Cold Brew Coffee?

You should use one part coffee to five parts of water.

Parts should be measured in terms of mass, with one milliliter of water weighing one gram.

I tested out different ratios of coffee to water. You can read my findings below:

Ratio (coffee to water)Verdict
1:3Very hard to extract the water from the coffee, I had to squeeze the filter to get it out. The coffee was revolting, it was so sharp I had to spit it out.
1:4Extracted ok, not the clearest drink. Too sharp to drink black but nice if you diluted it half and half with milk.
1:5Lacked the sharpness of the stronger concentrates and had a pleasant, almost savory flavor. Definitely the best so far.
1:6Noticeably more watery than the 1:5 ratio. Reminded me of a cheap Americano from a chain coffee shop.
1:7Virtually indistinguishable from the 1:6 ratio.
Photo of cold brew coffees with different strengths
All my different strength cold brews in a row (I know I have the handwriting of a toddler)

I have seen recommendations online about making stronger concentrates (I have seen anything from a 1:1 to a 1:3 coffee to water ratio being recommended) and then diluting this with milk or water before drinking.

I would only recommend making these stronger concentrates if you have a proper cold brew coffee maker as anything above a 1:3 coffee to water ratio became hard to filter using coffee filters alone.

Considering the amount of coffee that you need to make a 1:3 or stronger concentrate, I would not recommend using a French press for this either unless you have a particularly large one. There simply is not enough room for all coffee and water you need to make such a strong concentrate.

What Is The Best Grind Size To Use For Cold Brew Coffee?

You want to use as coarse a grind as you possibly can for cold brew coffee.

Ideally, you should be grinding the beans yourself to achieve this level of coarseness.

The coarsest grind I bought from the store was nowhere near as coarse as I could get it from my coffee grinder on the coarsest setting.

The coffee from my grinder is in the centre and the store-bought “coarse ground” coffee is on the left

To make sure that I was using the correct grind for my cold brew I made five cold brews out of different grinds on my coffee grinder and did a taste test. You can see my findings below:

Grind size (using a Delonghi KG79 electric blade grinder)Verdict
Finest settingSo sharp that it was undrinkable
Medium fineStill pretty much undrinkable. Might be okay if diluted heavily with milk
MediumA bit on the sharp side but still passable
Medium coarseIndistinguishable from medium grind
Coarsest settingCame out a beautiful syrupy consistency and had the best balance of flavor

The coarseness of your grind does make a big difference to the final flavor of your cold brew.

Unless you can get your hands on preground coffee that is specifically ground for cold brew I would recommend grinding your own as coarsely as you possibly can.

Can You Have Cold Brew Coffee Hot?

Yes, heating up a cold brew will make a very smooth, sweet filter coffee.

This was preferable to a standard filter coffee was it had a sweeter, more mellow flavor.

Is Cold Brew Coffee Easier On The Stomach Than Regular Filter Coffee?

I found cold brew coffee to be easier on my stomach than regular filter coffee.

This did, however, lead me to drink more coffee than I otherwise would which led to a caffeine crash.

Try to resist drinking too much of this coffee in one go. Its relatively mellow flavor can be deceiving as to how much caffeine it contains. If you want to find out more about the amount of caffeine in different types of coffee, please visit our how much caffeine in coffee page.

Final Verdict On Cold Brew Coffee

Cold brew coffee got the thumbs up from me, so much so that I bought a cold brew coffee maker once this experiment was over.

It is particularly good for iced coffees given its smooth flavor, so I will be using it mainly for that.

It would be my daily coffee of choice if it didn’t require so much coffee to make. You need about two ounces (60 grams) of coffee for one cup, so even with cheap beans, this will become an expensive habit if you do it daily.

If you do not want to pay for a cold brew coffee maker (they cost around $20-$30 depending on size) then you can make a decent cold brew in a French press so long as you only need to make enough of it for one person.

I also have a guide on how to make the best coffee in a French press if you have recently bought this coffee making device but are unsure how to use it to its fullest potential.