barismo coffee

Cold Brew Guide

Cold brew has a reputation as being flat, chocolaty, and lacking in acidity -- but it doesn't have to be that way. The majority of cafes serve cold brew that is simply a very large dose of coffee and water steeped overnight in a bucket at room temperature, and filtered through a simple mesh strainer, with the resulting product then diluted. The combination of room temperature brewing and poor filtration leads to disappointment.

We use a different method for cold brew that produces a ready-to-drink beverage that reflects the same origin flavors we find from a coffee in the hot cup. It's all about the basics: appropriate brew ratios, brewing cold, fine filtration & good storage. This method is different than the technology we use to brew cold coffee in stores, but is an alternate method that works well for home kitchens.

  1. We recommend no larger than a 1 liter batch size for brewing at home. With regular home storage, cold brew has a limited shelf life (3-5 days max). Only brew larger batches if you are sure you can use it in that time window.
  2. Make sure your water is cold; pre-chill in the refrigerator if needed. The goal is to brew below 40 F. For home brewing, mason jars are our preferred vessel.
  3. Grind 80 - 90 grams per liter (depending on preferred brew strength) on a medium grind setting. This should be finer than what you might use for a press pot.
  4. Add your freshly ground coffee to your chilled water and stir. You want to ensure that the coffee is able to become fully saturated. Seal the vessel and store in the refrigerator.
  5. After 1-2 hours, agitate again. This will ensure that the coffee is incorporated with the water fully, rather than rising to & sitting at the top while off-gassing. If possible, we find best results when you agitate again at the 12 hour mark.
  6. At the 22-23 hour mark, agitate once more and strain. Decant the brew liquid through a metal strainer to remove larger particles, then strain again through cloth or polypropylene. Cloth is easily cleanable & re-usable; a woodneck brewer works well for this. You may have to clean the cloth in between batches to avoid it clogging with fine particles.

    Food grade polypropylene bag filters are more efficient, especially for larger batch sizes. They come in a variety of sizes & filtrations, down to 1 micron or finer. We find 1-5 microns work well. However, unlike cloth, polypropylene is difficult to fully clean after use, so consider them a one time use product.
  7. Once filtered, cold brew should be stored in a refrigerated minimal oxygen environment. The easiest way to achieve this is by storing it in a sealed vessel that is completely filled, so that there is minimal headspace. On a commercial level, nitrogen-flushed kegs can preserve the product for a significant period of time.

Cheat Sheet

Brew Ratio: 80 - 90 grams per liter

Steep Time: 23 hours

 Temperature:34 - 39 F

 Filtration: cloth or polypropylene