Commercial-style cold brew concentrate maker for large batches at home
Filtron Cold Water Brewer: Large-batch concentrate with professional-inspired design
The Filtron Cold Water Brewer at $35 is one of the original home cold brew systems, inspired by the commercial Toddy method. It produces a low-acid coffee concentrate by immersing coarse grounds in cold water for 12–24 hours, then draining through felt and paper filters into a glass carafe. The result is 10–12 cups of concentrate per batch — enough to last most households a week or more.
What works
The immersion-drip method the Filtron uses produces concentrate with notably low acidity compared to hot-brewed coffee. If you find regular coffee irritates your stomach or tastes harsh, cold brew concentrate made this way is often more tolerable. The large 80oz batch capacity means you can make a full week's supply in one preparation session, which is efficient compared to daily brewing.
The reusable felt filter is a design point in the Filtron's favor over systems that require expensive paper filters for every batch. While replacement filters are an ongoing cost, the felt filter lasts multiple uses before replacement.
At $35, the price is fair for a purpose-built cold brew system that produces high-quality concentrate.
What doesn't
The Filtron's bulk is a genuine constraint. The brewing vessel, filters, and carafe take up meaningful counter and refrigerator space, which is a real issue in smaller kitchens. Storing the full system between batches requires planning.
The paper and felt filters wear out and need replacement — an ongoing consumable cost that the glass-carafe alternatives like the Hario Mizudashi don't incur. This is a minor but recurring expense.
Who should buy this
Regular cold brew drinkers who want a large batch that lasts the week and don't mind a bulkier system. If you drink one to two glasses of cold brew daily and want to make it at home rather than buying bottles, the Filtron is efficient and cost-effective at scale.
Who should look elsewhere
For lighter cold brew users or smaller households, the Hario Mizudashi ($40) or Takeya ($30) offer smaller, cleaner systems with less counter footprint. If you want smaller batches with no consumables, go for the Ovalware RJ3 ($25).