Cold brew is most commonly made with coarse ground coffee, but JARVA works efficiently with medium ground as well.

• Coarse Grind (similar to sea salt) – This is the standard for cold brew, allowing for faster, smoother filtration. For home grinding, use a conical burr grinder to achieve consistent results and minimize fine particles that could slow the filtration process.
• Medium Grind (like sand) – JARVA’s pressure-based filtration and multiple filters handle medium grind with ease. Medium grind can enhance flavor, require shorter steep times, and allow more coffee to fit in the jar, increasing yield. However, some medium ground coffees may contain fine powder that can slow filtration, depending on the roaster or brand.

Important Note: Avoid fine ground coffee (similar to flour). Fine particles can clog the filters, causing slow or incomplete filtration. This often results from low-quality or older grinders that produce uneven grounds. To prevent issues, stick to coarse or medium grind and sift out any excess fine particles if necessary.

A simple way to start is by adding 8oz of coffee to your 64oz mason jar, then filling the jar with water. Once the water soaks in, the mixture should sit at least 1 inch below the rim.

After filtration, this will create a strong concentrate that can be diluted to taste—anywhere from 1:1 (equal parts concentrate and water) to 1:2 (one part concentrate to two parts water or ice).

There is no single correct ratio—it depends on how strong you prefer your concentrate or if you want it ready to drink right away.

If ratios seem confusing, check out our brew guide and calculator for easy reference: JARVA Brew Guide & Calculator.

Yes, you can use pre-ground store-bought coffee.

Most pre-ground coffee found in stores is typically medium grind, which works well with JARVA’s pressure-based filtration. However, coarse ground coffee is not commonly available in grocery stores but can often be requested at local roasters or purchased online.

Keep in mind that some pre-ground coffee from roasters may contain fine powders that can slow filtration or affect performance. Results may vary by brand, so it’s worth experimenting to find the best fit.

Steep the coffee for 12 to 24 hours at room temperature or in the refrigerator.

• A 12-hour steep produces a lighter, more delicate flavor.
• A 24-hour steep results in a stronger, richer concentrate.

If using medium grind coffee, consider a shorter steep time to avoid over-extraction.

Experiment within this range to find the perfect flavor strength that matches your taste preferences.

Adjust the strength of your cold brew by modifying the coffee-to-water ratio during brewing or the dilution after filtration.

• For a stronger concentrate, use more coffee or less water during the brewing process.
• To make it weaker, reduce the coffee amount or increase the water.

After filtration, dilute the concentrate to taste. A common starting point is 1:1 (equal parts concentrate and water/ice), but you can adjust to 1:2 or more for a lighter brew.

Experimenting with different ratios and steep times will help you find the perfect strength for your taste.

Yes, you can make cold brew tea or other beverages with JARVA.

The system works similarly to cold brewing coffee—simply steep loose-leaf tea in cold water for 8 to 12 hours, then filter using the JARVA system. This method creates a smooth, less acidic tea concentrate.

Popular cold brew teas include Hibiscus, Yerba Mate, and Herbal Teas.

Feel free to experiment with different teas, herbs, or fruit infusions, but avoid using fine powders or overly small particles, as they may clog the filters.

For cold brew, medium to dark roast coffee beans are typically the best choice due to their bold flavors and lower acidity, which shine through even when diluted. Medium roasts offer a balanced flavor with subtle sweetness, making them a versatile option for most palates. Dark roasts provide rich, chocolatey notes and a smoother, less acidic profile, perfect for those who enjoy a bolder, more full-bodied brew.

When it comes to origin, Latin American beans are favored for their chocolate and nut flavors, while Indonesian beans deliver earthy, full-bodied, and spicy undertones. For a brighter, fruitier brew, African beans like Ethiopian Yirgacheffe offer floral and citrus notes, resulting in a more nuanced, lighter flavor profile.

Single-origin beans highlight the distinct characteristics of a specific region, making them a great choice for coffee enthusiasts seeking unique flavors. On the other hand, blends provide a consistent and balanced flavor, combining the best of different regions.

Popular choices for cold brew include Colombian Supremo, Brazilian Santos, Sumatra Mandheling, Ethiopian Yirgacheffe, and Guatemala Antigua. To maximize flavor and avoid over-extraction or bitterness, always use coarsely ground beans during steeping.

Cold brew concentrate can last up to two weeks in the fridge when stored in an airtight container.

For the best flavor, consume it within the first 7 to 10 days. Over time, the concentrate may lose some of its freshness and strength, but it will remain safe to drink for the full two weeks.

It can also be frozen to preserve its life and maintain freshness for an extended period.