Two words: hot bloom.
We write a lot about cold brew here at Trade. It’s a tremendously easy way of making coffee and people really like it. But here’s the thing: there’s a vocal group out there that doesn’t love cold brew.
While some folks prefer cold brew’s lower acidity, others miss that brightness — as well as the aromatics that hot brewing methods are better at extracting. Is there a way to get at some of that acidity while not sacrificing the ease of cold brew? There kind of is!
By starting your cold brew off with a little bit of hot water, you can extract a little of those tasty acids that cold water can’t dissolve. I’ve most commonly found this concept referred to as "Hot Bloom Cold Brew", which is a pretty fun phrase to say. Bloom, which we touched on in our article on degassing, usually refers to the first step in many of our hot brewing recipes. Put simply: it's when we add a little bit of our hot water (usually around twice as much water as our dose of coffee, by weight) and wait 30 to 45 seconds while that initial soak causes carbon dioxide to escape the grounds, making it easier for the remaining water to get in there and do its job.
I first learned about this brew method in 2014, when Lorenzo Perkins, then at Cuvée Coffee, published a detailed Tumblr describing the method that has now seemingly been lost to the winds of time. The earliest mention I can find of it, however, dates back to 2010, when Jesse Raub (now of Ruby Coffee Roasters) wrote a blog post detailing a hot bloom cold brew experiment based on conversations between him and Jesse Kahn (now of Counter Culture).
Lorenzo and Team Jesse all wrote out specific recipes, but this is a concept you can apply to pretty much any cold brew recipe. Use the same total amount of water, but start out with some water around 200 degrees Fahrenheit. Let the coffee sit in that water for 45 seconds, and then fill the container with a mix of cold water and ice (you’ll want to cool your hot brew quickly, both to slow down the extraction and stop it from oxidizing too quickly). Then, let your cold brew sit for as long as you regularly would and enjoy.
For an example, adapting our Cold Brew Bag recipe would look something like this.
- Fill your bag with 85 g of coarsely ground coffee
- Place in a heatproof container
- Pour in 200 g of water at 200 degrees Fahrenheit, trying to soak as much of the bag as possible
- Wait 45 seconds
- Pour in 260 g of water and 250 g of ice and stir
- Cover and let sit 12 hours, either on the counter or in the fridge
Will hot bloom cold brew taste exactly like hot coffee? It won’t. There are still certain compounds that need a combination of heat and time to extract properly. But is it a fun middle ground for both cold brew partisans and hot coffee loyalists to explore together? We think so!