How to make cold brew concentrate?

Question

I enjoy the smooth taste produced by my Mizodashi cold brew jug, but prefer hot coffee. Although I can dilute the cold brew with hot water, it gives me a pretty weak coffee (although great tasting).

So, the basic question is how can I create a concentrate with the smooth taste of cold brew that I can take into work and make my own coffee?

Answer 1

Like @Shiri said in comments above (and hopes that I'm not answer-sniping), most recipes for cold-brew are concentrates. Within reason, try brewing with a smaller amount of water! Compare guides like Kicking Horse, Stumptown, Blue Bottle.

In my experience (except for the problems that I've had with filtering) brewing a lower volume of water generates very similar results when diluted. Said the other way, brewing with a higher ratio of coffee :: water, then diluting, is my preferred way of brewing, storing, and consuming.

That said, do store in a neutral vessel that is easy to clean (my preference is a wide-mouth glass jar). Stored in the fridge, it will last several days (maybe a week) and still taste okay. In a plastic jug (or so) it might 1- start to obtain bad tastes from the container, and 2- infect the jug with stale coffee taste over time. Coffee oils (etc.) can be hard to remove especially when cold.

Some additional information is in related questions are about ratios and concentration and a concentration table in this answer.

Answer 2

This is my first answer, and I'm sharing my own personal method for making concentrate. Hope this helps!

First: Source your coffee!

My preference is very fresh, bright, fruity blends direct from a roaster or coffee house; a reputable barista will have a suggestion of which one makes a good cold brew. I strongly advise against cold brewing grocery store coffee as the resulting flavor will not be worth the effort, even when buying the more expensive, grind-it-yourself coffee. It's not fresh enough!

The grind should be slightly coarser than what would be used for a regular drip coffee maker and generally your barista will gladly grind for you.

Most important:

Use a 1:1 ratio, ounces coffee :: cups water

Examples:

• 1 ounce coffee : 1 cup water
• 4 ounces coffee : 4 cups / 1 quart water
• 12 ounces coffee : 12 cups / 3 quarts of water*
• 16 ounces coffee : 16 cups / 4 quarts / 1 gallon water

*This is my most common ratio; I consistently get 11 cups of concentrate from 12 cups of water. This results in about 11 pints of coffee when mixed as directed.

Useful tools:

1) Large container in which to brew. Make sure you can cover the container to keep out contaminants. A pitcher or carafe with lid is ideal, and a wide-mouth will help with cleanup and removal of the used grounds. My preference is glass but plastic may be adequate. Previously I had recommended the Bormioli Rocco Airtight Jar in 5 liter capacity but have found that it isn’t ideal when brewing with a bag.

2) A sieve, bag, or both to strain the mixture after brewing and before filtering. A nut-milk bag is especially useful - I've been using one to brew and it has made the filtering process quite a lot quicker, cleaner, and easier than filtering with a sieve alone.

3) A fine filter to remove the smaller silt from the mixture. A regular paper coffee filter is the perfect tool for this step, naturally, and you can use the sieve mentioned above to support it.

Steps:

Measure out coffee and water separately.

If you're using a bag to brew, place the bag in to the container, then fill the bag with the coffee.

If you're not using a bag, simply put the coffee in to the container.

Slowly pour the water over the coffee to soak the grounds completely.

Close up your container for about 10 minutes in order to allow for the coffee grounds to become saturated through.

If you're not using a bag, you'll notice all the grounds at the top of the mixture at the end of the waiting period; if you are using a bag you probably won't notice any difference. In either case, use a non-metal (wooden or plastic) spoon or spatula to submerge the grounds in to the mixture. If you're using the bag, treat it like a teabag and simply dunk it repeatedly. If you're not using a bag, you can mix vigorously.

Allow to brew for 24 hours at room temperature. Periodically you may wish to agitate the mixture as the grounds may sink to the bottom if you're not using a bag, and we want to maximize the coffee grounds contact with the water in order to maximize the flavor extraction.

After 24 hours, strain & filter out coffee grains.

Bag method: - Remove bag - Empty grounds in to bin and rinse bag - Pour mixture through paper filter in to storage container

Sieve method: - Pour mixture slowly through sieve in to intermediate container - Empty sieve as necessary through process - Pour mixture through paper filter in to storage container

The strained mixture will be a concentrated brew of the most delicious nectar of nature. Mix resulting concentrate with water at 1:1 ratio to serve; my preference is chilled with ice but it's also quite delicious if boiling water is added to the room temperature concentrate.

Answer 3

There are at least four "flavor dials" that you can tune to get a stronger flavor out of cold brewing.

1. The roast. A darker roast may produce a stronger flavor, but maybe you don't like darker roasts. Keep in mind that the cold brewing process will produce a smoother result, so you might be pleasantly surprised by the results.
2. The temperature. You can try putting warmer water into your coffee initially, or warming it up right at the end. This may extract more flavor. Obviously it goes against the principle of cold brewing, and it might extract some flavors you don't like. But it's worth trying to see what you think.
3. The grind. A finer grind may extract more flavor, but you'll have to pass the concentrate through filter paper in that case.
4. The ratio of coffee to water. Use less water to more coffee for a stronger flavor.

If you try all of those things and it's still too weak, then I really don't know what to say!