Ah, the age-old question: Which cold brew is right for you?
We got this cool new slow drip brewer in the online shop today, and it spurred a debate on the best way to cold brew. There are two main methods: full immersion and slow drip. Before we get into the differences, here’s a breakdown of each method.
Full Immersion: In this method, coarse-ground coffee is fully steeped in water for up to 16 hours, then filtered for drinking. You can do this in any kind of vessel (French press, large jar, bucket), and you can use a paper or cloth filter.
Slow Drip: This method has gained popularity in Japan, and involves slowly dripping cold water over coffee grounds and through a filter. The coffee never sits in the water so there is less extraction, and the slow drip brewer takes care of the filtering step for you.
The Taste Test
To settle the matter, we prepared the same coffee on both brewers to compare. We used our For Haiti seasonal blend, because the chocolate, vanilla, and black pepper notes make a flavorful, bodacious cold brew.
For the full immersion brew, we used a Simple Brew Iced Tea Teapot, which is just like a French press without the plunger. We did a coarse grind and a 1:7 coffee to water ratio, steeped for 6 hours.
For the slow drip, we used our new Bruer, which features 3 chambers: one for the water, one for the coffee, and one to catch the cold brew. Since the water is flowing through the coffee, we went for a medium grind instead of coarse. The makers of the Bruer recommend using a ratio of 60g of coffee to 700g of a water and ice mixture, which helps keep the water flowing through the valve.
The Results
Full Immersion: Our tasters described this coffee as having stronger flavors and more body. Unless you double and triple filter, full immersion cold brew will always have a little bit more sediment and body than slow drip. Some people really like the sediment, which tends to produce more chocolate-y notes. Our folks also thought full immersion had a bit more acidity and bitterness (not always a bad thing).
Slow Drip: “Mellow,” “clean,” “tea-like.” The Bruer turned our dark roasted blend into a light, syrupy brew, extracting citrus flavors we had never tasted in the For Haiti before. Very low acidity and noticeable sweetness, uber smooth and uber clean (free of sediment), but not lacking in body. And the really nice thing about the Bruer is the convenience: you don’t have to remember to filter it, so you can just set it up and leave it until the morning.
So, which method wins? Well, like everything in coffee, it depends on your personal preferences. It depends on whether you like a clean cup or some sediment, chocolate notes or fruit notes, heavy body or light body. It depends on the weather, your mood, the alignment of the stars, what you had for breakfast. Above all, it depends on what tastes good to you.