> ## Documentation Index > Fetch the complete documentation index at: https://colipse.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Cold Brew > How to brew smooth, low-acid decaf cold brew using extra-coarse grounds and a long cold steep. *Cold brew is the one format where removing caffeine and removing acidity happen at the same time - making decaf cold brew genuinely useful for anyone who loves coffee but is sensitive to either.* Cold brew is made by steeping coarsely ground coffee in cold or room-temperature water for 12 to 24 hours. No heat is involved at any point. The result is either a concentrate (diluted before drinking) or a ready-to-drink brew, depending on your ratio. The absence of heat is what defines cold brew - it is not just iced coffee. ## Why Does Grind Size Matter So Much for Cold Brew? Cold brew requires an extra-coarse grind, coarser than French press and significantly coarser than drip. Finer grinds create two problems: over-extraction (producing bitterness) and difficult filtration (grounds clog filters and make the brew murky). An extra-coarse grind gives water enough surface area to extract over a long steep while remaining easy to strain cleanly. Colipse Decaf Cold Brew Grounds are pre-ground to an extra-coarse size optimised for cold brew extraction, so you do not need to grind at home or adjust a setting. ## What Ratio Should You Use? The right ratio depends on whether you want a concentrate or a ready-to-drink brew. **For concentrate (recommended):** Use a 1:4 to 1:5 ratio of coffee to water by weight. For example, 100g of coffee to 400-500ml of water. A concentrate is stronger than you would drink directly - dilute 1:1 with water or milk before serving. Concentrate keeps longer in the refrigerator and gives you more flexibility. **For ready-to-drink:** Use a 1:8 to 1:10 ratio. This is weaker during brewing but ready to pour over ice without further dilution. ## How Long Should You Steep? * **Room temperature:** 12 to 16 hours. Extraction is faster at room temperature. * **Refrigerator:** 18 to 24 hours. Colder water extracts more slowly, requiring a longer steep. Do not exceed 24 hours at any temperature. Beyond that point the brew becomes bitter and flat as undesirable compounds accumulate with continued extraction. ## How Do You Filter Cold Brew? Strain the steeped brew through a fine mesh strainer lined with a paper filter, or use a dedicated cold brew filter bag during the steep itself. For the clearest result, double-filter: strain once through a mesh, then again through a paper filter. This removes fine particles that make the brew cloudy and affect the texture in the glass. ## Is Decaf Cold Brew Lower in Caffeine Than Regular Cold Brew? Yes - but not for the reason most people assume. Regular cold brew is often *higher* in caffeine than hot-brewed coffee, not lower. Because you use more grounds and a much longer contact time, more caffeine dissolves into the water. A standard cold brew concentrate can contain as much caffeine as an espresso shot or more. Decaf cold brew removes this concern entirely. Colipse uses Swiss Water® Process decaffeination, which is solvent-free and removes 99.9% of caffeine. The steep time and coffee-to-water ratio no longer affect your caffeine intake - every cup contains the same 2-15mg typical of any Swiss Water® decaf format. ## Why Is Decaf Cold Brew Especially Good for Acid Sensitivity? Cold brew is already the lowest-acid coffee format available. Research published in *Scientific Reports* (Rao and Fuller, 2018) found that cold brew has a pH of approximately 6.31, compared to approximately 5.48 for hot-brewed coffee. That is a meaningful difference in acidity for people who experience reflux, GERD, or irritable bowel syndrome triggered by acidic foods and drinks. Decaf cold brew combines both benefits: the lower acidity of cold extraction and the near-zero caffeine of Swiss Water® Process. For anyone who has felt they need to give up coffee entirely due to digestive sensitivity, decaf cold brew is often the format that brings them back. ## How Long Does Cold Brew Keep? Cold brew concentrate keeps for up to two weeks in the refrigerator when stored in a sealed container. Ready-to-drink cold brew is more dilute and should be consumed within one week. Always refrigerate after brewing - cold brew left at room temperature will deteriorate quickly and can become a food safety concern after 24 hours. ## Which Colipse Decaf Coffee product works best for cold brew? [Decaf Cold Brew Grounds](https://colipsecoffee.com/products/decaf-cold-brew-grounds) - Pre-ground extra-coarse, Swiss Water® Process, optimised for cold extraction. Available in one grind size designed specifically for cold brew. ## Related * [Cold Brew Extraction](/concepts/cold-brew-extraction) * [Acidity in Coffee](/concepts/acidity) * [Acid Reflux and GERD](/health-conditions/acid-reflux-gerd) * [Cold Brew Drinks](/drinks/cold-brew)