4 Tips for the Perfect Cold Brew Coffee
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With so many cold brew products on the market these days why should you make your own? It’s simple—money and control!
More specifically,
- the money you will save
- the control you have over creating the perfect cup of cold brew coffee.
The perfect cup that suits your taste buds perfectly.
That means there is no one universal “best” way because we all have different taste preferences. However, if you follow these four simple guidelines, with a little bit of experimentation you will find your best way!
1. The Beans
The type of beans you use greatly affects the flavor of your coffee. This is where personal preference matters most.
There are two things to look for:
- Location
- Roast
Location: In studying commercial cold brew coffees, I found that the majority of companies are using beans from Central and South America. In my testing, this has been my favorite as well. I have also had good success with Kona blends.
Roast: Degree of roast seems to affect flavor as much or more than bean origin. Medium roasts are my favorite. I find that dark and French roasts lend a smoky nuance to the coffee that I don’t like. Some commercial cold brew makers opt for a blend of roasts.
What else to look for:
The golden window for the best flavor from roasted coffee is between a day and a few weeks after roasting.
When buying coffee from the supermarket, you are not likely to know when the coffee was roasted. Instead, you can:
- Find a local roaster that can sell you freshly roasted beans
- Roast the beans yourself
With the availability of artisan coffee roasters in nearly every town, finding a local roaster shouldn’t be too difficult. But where is the fun in that? Why not try roasting beans yourself?
More about beans and roasting:
2. The Grind
As a general rule of thumb, the longer the contact time between water and coffee, the coarser the grind should be.
Size Matters:
- Choose coarse grind when possible
- Grind whole beans right before use
- If using smaller than coarse ground, adjust steeping time to be shorter
A 2019 study on the effects of grind and extraction on cold brew coffee found that the greatest TDS (Total Dissolved Solids) occurred when coarse grounds were immersed for 22 hours (vs. medium grounds at the same time). Even at 14 hour immersion times, coarse grounds resulted in greater TDS.
The same study, however, found that the best flavors overall were from coarse grounds immersed for 14 hours.
Since cold brewing (by immersion) involves hours of contact time, a coarse grind is recommended. Coarse grinds have less surface area than finer grinds.
Long extraction times with finer grinds may result in over extracted coffee, which tastes more bitter–a flavor cold brew lovers are often trying to avoid.
What about pre-ground coffee? Much of the coffee on the supermarket shelf is medium grind. In my experience, medium grind can work for cold brew. I steep about 10-14 hours with medium grind.
I recommend giving your container a shake once in a while to make sure these finer grinds don’t clump together while soaking, which could lead to incomplete extraction.
More about grinders:
3. The Water
Coffee made with terrible tasting water is going to taste terrible.
What to look for:
- Use filtered water when possible, or
- Bottled spring water
- Do not use distilled water, we want some minerals present
I recommend filtered water. If you have a fridge that dispenses filtered water, you should be good to go.
Otherwise, consider an inexpensive option like the Brita Water Pitcher (affiliate link, Amazon). This is what I used for years before I had a fridge with a water dispenser.
There are also filters that you can install on your tap.
If your water tastes off even with filtration, consider bottled spring water. This can be picked up inexpensively from any supermarket in bottles, gallons, or 5 gallon containers.
Finally, cold brew tastes great on ice. Make sure your ice cubes are also made from filtered or spring water. Or, freeze a little extra cold brew in an ice cube tray and use coffee ice cubes!
I have a whole article on the best water for cold brew if you want to dig deeper into this topic.
I don’t recommend distilled water, which is very flat and flavorless on it’s own.
4. Time
The sweet spot for immersion methods is 14-20 hours.
But consider:
- Steeping time is related to temperature of your water
- Steeping time is also related to the size of coffee grind you use
The sweet spot for immersion methods is 14-20 hours.
More than 24 hours and you run the risk of over-extraction.
Less than 12 hours? Researchers have found that a lot of extraction has occurred in just 2 hours, so if you want the 80/20 of extraction don’t feel like you have made a mistake. If it tastes good, do it!
Now, 14-20 hours is a pretty big window so how do you decide?
Determine time by factoring in the temperature at which you brew, and the coarseness of your grind.
Temperature
You can make cold brew at room temperature or in the fridge. My preference is in the fridge because in just 24 hours on the countertop, stuff can start growing in water. I am very risk averse when it comes to food safety. However, if you prefer room-temperature—there is re-assuring news for you:
Read about a Challenge Test for Cold Brew coffee (not much grew) and some concern about botulism in nitro-cold brew (possible, but not likely).
Back to time—if you brew at room temperature, you can choose shorter brew times (e.g. 12-20 hours). If you brew at colder temperatures, you can choose longer times (16-24 hours).
Grind
If you use coarsely ground beans, choose longer brew times.
The finer your grind (let’s say you use pre-ground supermarket coffee) the shorter your extraction time. I have gone as little as 7-8 hours with medium ground coffee with good results.
Other Tips to Make Your Cold Brew Better
What ratio should I use for cold brew?
Most cold brew is made as a concentrate and then diluted to taste.
The ratio for creating a cold brew concentrate is: 1 part coffee to 3 parts water. So, if you use 1 cup of coffee, add 3 cups of water.
The ratio for ready to drink cold brew is: 1 part coffee to 4-6 parts water.
If you plan to mix your cold brew with hot water to create hot coffee, I recommend making a concentrate.
If you want to drink your cold brew over ice, you can either make a concentrate or ready to drink.
Remember: you can’t make it stronger if your brew is too weak, but you can always dilute a brew that is too strong, so err on the side of a stronger brew.
Storage and Preparation:
You can store any coffee or concentrate that you don’t use for up to 1 week in the fridge, however unless you are making big batches at once, I doubt it will last that long before someone drinks it!
To prepare hot coffee, fill a mug 50% full with concentrate, and add near boiling water to it to make up the remaining 50%.
To prepare iced cold brew coffee, pour your concentrate in a glass and add ice. Dilute with water as needed to achieve your preferred strength. If your coffee is at room temperature, the ice will melt and dilute it a little so don’t be too quick to add water.
Preparing the perfect cup of cold brew takes just a little time and effort, but isn’t that true for many of the best things in life? Be sure to reward yourself by taking the time to savor your perfect cup of coffee you have so carefully prepared.
Should I stir cold brew while brewing?
Yes, I recommend stirring or shaking your grounds and water when you first start brewing. This helps all the grounds to disperse in the water, increasing contact between the coffee and water.
Not shaking or stirring may cause your grounds to float for awhile or clump, decreasing contact between coffee and water.
You don’t need to do any additional stirring unless you want. I often brew in a mason jar and when I open the fridge for some other reason, I might pick up the jar and give it a little shake.
