History Lesson: The origin of cold brew coffee.
So, many of you may ask or have already asked us this question: What is cold brew coffee? To be short, it's cold coffee. There you go, simple right? Well, not quite... There are two main forms of "cold coffee", those being iced coffee and cold brew coffee. Both are very different, but let's save that for another blog post, found here: Iced Coffee VS. Cold Brew Coffee. This blog post is about the origin of cold-brewed coffee that our company at STIR Mobile Coffee has begun producing and bottling.
The first true record of cold-brewed coffee (made with cold water) comes from Kyoto, Japan in the 1600's. Although, some may speculate that cold-brewing coffee was actually invented even earlier by Dutch traders, who would have used this method to make coffee that would have a shelf-life long enough to carry on their ships. Origins aside, the Kyoto Method of cold-brewing coffee is the first actually recorded and has since become highly artistic over the centuries that many modern coffee shops like to feature and display.
While a more contemporary approach to cold-brewing coffee is more or less tossing coffee grounds into a porous bag that is submerged in water for a long time, the Kyoto Method cold-brews coffee slowly drip-by-drip. Kyoto cold-brewing is typically performed by use of a three-tiered glass tower (think/visualize a large chemistry set). Let's start with the middle tier, this is where fresh coffee grounds are placed with a filter covering the hole in the bottom of the chamber. The coffee grounds are then lightly soaked and gently stirred to ensure that as water drops in from above, that the water can penetrate and soak through the grounds appropriately.
Next, we'll talk about the top tier, which is usually a large round glass bulb that is filled with ice. Choosing your ice source is very important when Kyoto cold-brewing your coffee, but this may vary greatly depending on your personal taste and local water sources. The top tier is then primed with a few ounces of room temperature water once filled with ice to expedite the melting process. As the ice melts, it slowly drips through an adjustable nozzle at a carefully controlled rate into the middle tier containing the coffee grounds. One drip every second-and-a-half has proven to be a good rate in which to cold-brew coffee via this method.
Last, is the bottom tier, or what we could call the retention chamber where the cold-brewed coffee collects as the ice in the top tier melts and drops down into the middle tier soaking through the coffee grounds into the bottom tier. This entire process generally takes anywhere from 8-12 hours or can be left overnight. Kyoto cold brew coffee generally produces a concentrated cold coffee as well and thus, needs to be diluted before consuming.
Since the 1600's, cold brew coffee has come to the US and other regions of the world where people have made it with a French Press or with the Toddy System as two popular methods. However, there is always room for innovation when it comes to cold-brewing coffee. Today, cold brew coffee is becoming more accessible through coffee shops and bottled products as popularity continues to rise with increasing market demand.
Written and posted by: Alexander Rubin, STIR Mobile Coffee, Co-Owner