Brewing Lab #02: The Logic of Cold Brew & Hand-Drip Bypass
Following up on our previous discussion about brewing ratios, once we transition from hot water to cold, or when we want to gain greater control over the texture of our coffee, the logic of brewing evolves. This time, we’re diving into two common but distinct techniques: Cold Brew Concentration and the Bypass dilution method.
【Brewing Quick Guide】
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Cold Brew / Ice Drip (Concentration-first): Recommended ratio 1:10 ~ 1:12. Since bitterness is less easily extracted at low temperatures, we brew a concentrate and adjust with ice water to taste.
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Hand-Drip Bypass (Clarity-first): Recommended ratio 1:15 (Base). Brew a concentrated base and dilute with clean hot water afterwards to minimize unpleasant notes from over-extraction.
1. Cold Brew & Ice Drip: Mastering Flavour Control
At Colour Brown, we often adopt a 1:10 to 1:12 ratio for our Ice Drip or Cold Brew. This isn't about saving water; it’s about reclaiming "sensory autonomy."
｜Cold Brew/Ice Drip Practical Steps:
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Ratio Setup: For 50g of coffee grounds, use 500ml - 600ml of cold water.
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Extraction: Mix well (for Cold Brew) or adjust the drip rate (for Ice Drip). Let it steep or drip in the refrigerator for 8–12 hours.
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Dilution Logic (The "Bypass"): The result is a "concentrated base." Before drinking, try it undiluted, then add ice or water at a 1:1 ratio (or to your preference). You will notice that as the temperature drops and the water blends, the deep, roasted aromas become much more vibrant and multi-dimensional.
Why do this? At low temperatures, our palate becomes less sensitive to bitterness but more attuned to body and texture. By brewing a concentrate and diluting it later, you maintain control over the intensity, ensuring you never end up with a watery or diluted cup.
2. The Art of Hot Brewing: The Bypass Method
If you find your hot pour-over coffee has an astringent or "dry" finish, it’s time to try the Bypass technique. This approach splits brewing into two phases: "Extraction" and "Dilution."
｜Hand-Drip Bypass Practical Steps:
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Concentrated Extraction: Use a slightly finer grind than usual. Brew with a ratio of approximately 1:12 using hot water.
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Flavour Separation: Stop the pour once you reach the target volume. This concentrated liquid holds the most intense, full-bodied flavours.
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Dilution Adjustment: Add clean hot water (the "Bypass") to reach your target total volume—typically a 1:15 or 1:16 ratio. This preserves the sweetness from the middle phase of extraction while avoiding the woody, astringent notes that often emerge in the later stages.
Data provides the structure, your palate decides the joy.
Whether you’re crafting a velvety texture with Ice Drip or pursuing clarity through the Bypass method, these techniques exist to let every coffee shine in its own way.
Data and ratios provide the foundation, but the true beauty of coffee lies in the moment you make that manual adjustment. Next time you brew at home, try adding a splash of sparkling water to your cold brew concentrate, or experiment with a Bypass on your morning pour-over. Who knows? That perfect cup you’ve been chasing might just be hidden in these subtle adjustments.
Editor: Barista S
Ready to experiment? Choose your favourite beans from our Coffee Collection and find your perfect brewing companion in our Equipment Shop to start your journey today.
