If you are reading this blog, you have probably noticed that cold brew coffee is everywhere, and you want to learn how to make cold brew coffee at home.
I’m with you! I like to try almost every new coffee innovation that comes my way. I have even done some back yard innovation (like my Frankenstein BBQ grill coffee roaster).
In this blog I will talk about how to choose the right beans for your cold brew, how to grind beans for cold brew, how to make cold brew, what cold brewers are on the market, and provide a few extra tips.
Let’s dive in!
Best Coffee Beans for Cold Brew
What is the best coffee for making cold brew?
If you do a quick search on Google for “best coffee for cold brew” you will find a lot of people recommending their coffee brands but not a lot of solid advice (ps, most of the recommended brands have easily accessible affiliate marketing programs, so you see the same brands on page after page because the website owner is incentivized).
A general rule of thumb is to use whatever coffee you generally like for the cold brew.
Quality pays when it comes to cold brew, so make sure you are getting high quality beans (shameless link to my store).
Single Origin Coffee and Blends
Single origin beans can be a great selection for your cold brew. Instead of drinking a blend of coffee which tones down the individual flavors of each bean, SO beans allow you to home in on the unique flavor profiles that each region.
For a general rule of thumb when it comes comes to coffee origins and flavor, take a look at this map from Torch Coffee:
These flavor generalizations can be helpful, but there is also a lot of variation inside each region.
The downside to single origin coffees is that the can be inconsistent, especially if you have narrowed your favorite coffee down to a particular town or grower. Coffee’s flavor comes from environmental factors (soil, rainfall, shade, fertilization) and processing methods (honey, wet, dry, natural, washed). The effects of each of these factors can change a coffee’s flavor from year to year.
For a consistently good coffee, you should consider blends that contain your favorite single origins. Blends can be mixed to bring out certain characteristics such as fruitiness or nuttiness, while providing a more balanced, complete profile than a single origin coffee.
I suggest that as you go on your coffee adventures you
- keep an open mind
- drink single origin coffees
- sip a couple of samples side by side if you can
- read the flavor profiles on the label
- keep a journal of what you like and don’t like
- drink freshly roasted beans
Scientific Research on Cold Brew
Recent scientific studies on cold brew add additional insights. Dr. Niny Z. Rao, Ph.D. has been studying the chemical characteristics of cold brew and gives this advice,
“if you want to craft a coffee beverage with antioxidants or acidity in mind, you may want to pay attention to roast. If you want a low-acid drink, you may want to use a darker roast. But remember that the gap between the antioxidant content of hot- and cold-brew coffee is much larger for a darker roast.”
Dark roast coffees are less acidic than light roasts with any brew technique. Additionally, according to Rao’s research cold brew extracts proportionally less acidity from dark roasts than light roasts. So, if you are going for a low-acid drink, go for dark roasts.
If you are looking for a healthy drink full of antioxidants, however, you may want to go for a lighter roast. Hot brew methods extract about the same amount of antioxidants from dark, medium, and light roasts. Cold brew, though, sees a reduction of extracted antioxidants as the roast gets darker. So, dark roast may give you those chocolaty, nutty, earthy, syrupy notes, but may not be as healthy for you.
Take a look at the American Chemical Society’s easily accessible summary of the study here:
How to Grind Coffee for Cold Brew
In general, the more time coffee spends exposed to water, the coarser the grinds need to be. This is no exception.
Coffee Extraction
Let’s talk chemistry for a second.
Water is a solvent. When it comes into contact with coffee grounds it will dissolve a number of compounds in the beans to create your coffee drink.
Because coarse ground coffee has less total surface area than finely ground coffee, you will need to leave the grounds in water longer to extract all of the compounds. Finer grinds have more surface area exposed to water and therefore extraction goes faster. If you want a deep dive into how extraction works, take a look at Clive Coffee’s blog on the subject.
Clive Coffee summarizes the process in this way,
Regardless of the method, water will always extract the different flavor compounds in this order: fats and acids, then sugars, and finally the plant fibers. From a flavor and body perspective, it looks like this: Sour/Oily – Sweet/Syrupy – Bitter/Thin
An under-extracted coffee did not stay in contact with the coffee grounds long enough to bring out the sweet, syrupy sugars and will end up sour, oily, or salty. Try grinding your coffee beans finer, or leaving them in the water longer.
Over-extracted coffee on the other hand has stayed contact with the water for too long, and therefore ends up bitter, hollow, and dry. Try grinding your beans coarse, or decreasing the brew time.
Cold Brew Grind Size
Hot water increases the extraction rate verses cold water, so cold brew will take a lot longer to extract than hot brewed coffee. For that reason you want to have a nice coarse grind, about the same size you would use for French Press or slightly coarser. The good news about a slower extraction rate is that there is a larger margin for error. If you let the brew steep for 16 hours rather than 12, you should still get a good cup of cold brew.
The grinds should end up about the size of kosher sea salt, so a little chunky. You do still want to make sure the grounds are consistent.
Grinders for Cold Brew
If you need a nice versatile grinder that will do well for pourovers, French Press, and automatic coffee makers, here are a couple of recommendations:
- Hario Slim Mill – this is a great starter grinder, or grinder if you are on the move. Easy to pack into a lunch box or backpack and does a great job for a little investment.
- Baratza Encore – this grinder is a work horse. The Encore quickly and consistently grinds up coffee and easily adjusts for whatever grind you need (not the best for espresso though).
Making Cold Brew
Okay, it took us a while to get here, but hey, good job for making it this far! Now that you have chosen your beans and ground them evenly, you are ready to actually make your cold brew
Congratulations!
Coffee to water ratio
A good general rule of thumb is to use a 1:5 coffee to water ratio. That means if you are going to make 300g of finished coffee, you want to use 60g of coffee.
If you really want to dial in your brews, you are going to want to accurate weigh your beans, the water you are adding, and how much coffee you get as a result. Cold brew timing is measured in hours rather than minutes or seconds, so having a good timer is not as important. All the same, you might consider the Hario V60 Drip Scale as it is accurate to a tenth of an ounce an has a built-in timer.
Some prefer to brew their coffee closer to a 1:3 ratio, others a 1:7 (especially if you are using a French Press to make the brew – a 1:3 or even a 1:5 ratio may be too much for the press to hold).
This is all about you and your tastes, so experiment and find what you like!
Brew Time
For best results you want to let your coffee steep either in the fridge or on the counter for ideally 12-15 hours, up to 24 hours. After about 24 hours you start extracting less pleasant flavors. This doesn’t mean that you have to drink it within 24 hours, you just want to remove or filter the beans so they don’t keep steeping.
If you are using a French Press, you will want to store any cold brew you don’t use in another contain instead of just pressing the beans down. The beans will be at the bottom of the press, but will still be in contact with the water, getting extracted.
What comes out of your brewer will be a cold brew concentrate. You can drink it straight if you like, or cut with equal parts water per your tastes.
Whether you brew you coffee in the fridge or on the counter, refrigerate immediately after brewing. The coffee will be good for 7-10 days.
Cold Brew Coffee Makers
Mason jar – One of the easiest and cheapest ways to start is with a mason jar and cheesecloth. Simply mix you water and grounds in the jars, steep, and strain through the cheesecloth whenever you are ready. You don’t need to buy expensive equipment to make good cold brew!
French press – This is one of my favorite ways to make cold brew. If you are serious about coffee, you have probably picked up a French press along the way. They are cheap, make tasty coffee, and look fancy for your friends 🙂 Making cold brew in a press is very easy. You simply add your grounds and water, then simply plunge the brew 12 to 24 hours later.
With the mason jar and French press you will often get a lot of fine particles coming through the strainers. It can be helpful to run the cold brew through a paper filter to take care of the fine particles if that bothers you. You can also pour carefully and stop once the fines start making their way into your cup.
Toddy Cold Brew Home System – If you are ready to upgrade from mason jars and French presses and want to produce more cold brew at a time, take a look at the Toddy Cold Brew Home System. This brewer can make up to 72 ounces at a time, so about 9 cups.
Steeping brewers – There lots of specialized cold brewers on the market that basically steep your coffee as you would tea. The basic architecture is that you have a mesh metal basket that you put you grinds into and drop into the water. Let the grounds steep for 12 – 24 hours, then pull the basket out, removing the beans. With this method you have the added convenience that once you have removed the basket, the cold brew is already in the server. No need to filter into another mason jar or French press. Takeya and Ovalware both make quality cold steeping brewers.
Aeropress cold brew – The Aeropress is a very versatile tool and can even be used for a unique spin on cold brew. You can also use the recipe from the Aeropress website:
- Add 1 rounded scoop of fine drip grind coffee (we are doing a very fast extraction rather than the typical 15 hr+ extraction)
- Add tap water up to the coffee in the Aeropress
- Stir briskly for 1 minute (this is key to overcoming the difference in extraction times)
- Press gently
- Add tap or ice water to make an 8 oz. (237 ml) mug of cold brew, or cold milk for a delicious cold brew latte
Cold brew tower – This is one of the cooler, but more expensive ways to make cold brew. These are popping up in cafes all over (although not as quickly as nitro taps). In my experience this coffee tends to be more concentrated than other sorts of cold brew. For this method you will want to use a 10 or 11:1 water to coffee ratio and with one drip of water going into the beans a second. If you have an Aeropress and want a cheap brew tower, check out the PuckPuck.
Cold Brew Tips
- Coffee Ice – If you like to add ice to your coffee, but hate it when your brew is super watery, try freezing some cold brew or espresso in your ice tray and use to make your iced coffee.
- Flash Brew – Not a true cold brew, but if you don’t have 15 hours to wait for cold coffee, you can use your pour-over to flash brew. Replace 1/3 to 1/2 of your water with ice in the decanter/server and brew like normal. Quick cold brew! Works well with a Hario V60 manual brewer.
- Coffee + Milk + Sugar – If you like to doctor your drink with coffee, sugar, and flavoring, then check out this list of recipes!
Enjoy! Hit me with your best tips and favorite cold brew recipes!