How to make a delicious cold brew with the Hario Mizudashi

How to make a delicious cold brew with the Hario Mizudashi
With the heat of the summer finally upon us in Los Angeles, a walk to the nearest cafe can become a dauntingly sweaty chore. I suggest having cold brew stocked at home for those sweltering days. 

Groundwork sells Hario’s Mizudashi cold brew coffee maker at our cafes and online because it’s one of the most efficient gadgets for making delicious cold brews at home. Hario produces renowned coffee equipment that have been barista favorites for years. 

Here’s my barista guide on how to discover your own perfect cold brew recipe:

Choose the coffee variety 
An espresso blend can make good cold brew concentrate, while a medium or light roast is better for drinking black, in my opinion. 

Measure out the coffee
One cool thing about cold brew is that you can brew it as a concentrate for easy storage and for customizing the strength by diluting it later. Typical cold brew coffee-to-water ratios are between 1:2 and 1:15. Experiment with which ratios you like, keeping in mind that the Mizudashi carafe holds a little more than 1 L (1000 g) and that you can dilute the concentrate when it’s done brewing. 
The Mizudashi takes some of the guesswork away because, in order to fill the carafe enough to submerge the coffee grounds, you’ll need a higher brew ratio likely above 1:8. 
If you plan to add milk or other ingredients later, go for a more concentrated brew ratio. If you’ll drink it black or with just a splash of milk, go for a weaker ratio and it will taste more like a traditional iced coffee. 
 Since I like my final cup of pour-over coffee at a 1:15 ratio, I make my cold brew with a 1:10 ratio (115 g coffee: 1150 g water) so that I have the option of diluting it with up to 575 g water. For brewing efficiency, I chose the ratio that fills the carafe to the very top with the strongest brew possible. The instructions in the Mizudashi suggest using 80 g of coffee, which yields a weaker brew. 

Grind the coffee and pour it into the basket
Considering the long brew time, I grind the beans coarsely in order to avoid over-extracting the coffee. Usually, this means setting your grinder to one of the coarsest numbers. A coarser grind yields a lighter, more tea-like coffee, and a finer grind yields a more robust cup with more body. 
Still not sure where to start? Pick up our pre-ground cold brew blend as a landmark for coarseness. 

Slowly add water over the grounds in the carafe 
Water quality makes a surprisingly big difference in the flavor of your brew! Filtered water is best, and a simple faucet or pitcher filter can remove extra mineral buildup and other flavor contaminants. 
Make sure you fill the carafe all the way to the top of the grounds, so they’re fully submerged. This will take a little bit of time!

Secure the lid and let it steep in the refrigerator or a cool space for 12-24 hours
Experiment with the brew time to see what you like best.  Every distinct bean variety, processing method, and roast will have a different sweet spot for brewing time since all of coffee’s flavor compounds, such as acids and sugars, are extracted at different rates.  
I steep mine for about 20 hours, while taste-testing it occasionally after 12 hours.  

Dilute it to your taste 
Since the long brew time extracts more caffeine, dilute it or sip slowly! Remembering which brew ratio you used initially, calculate how much water you want to add. Or, just dilute by taste.

Add something fun! My favorite summer add-ins are: 
    1. Coconut milk cold foam: simply shake cold coconut milk with ice in a bottle or shaker cups, or use a frother method
    2. Vanilla syrup or extract. 
    3. A few squirts of fresh orange. Use the orange rind to mist a bit of zest on top then finish as a garnish. 
    4. Add all of the ingredients above for a dangerously delicious summer drink ;)
  • Store leftover concentrate for up to a week in the refrigerator 

  • Written by 
    Melina Devoney 
    Barista, Coffee Captain, Blogger