Ridgebrew 無漂白パーコレーターフィルターペーパー - 100枚入り

At a glance

Why unbleached cellulose produces a cleaner cup

Conventional filter papers are chlorine-bleached during manufacturing, a process that leaves trace chemical residues in the paper fiber. When hot water passes through at percolator temperatures — ideally 195–205 °F per Specialty Coffee Association (SCA) Brewing Standards — those residues dissolve into the brew and suppress the aromatic compounds that define a roast's character. Oxygen whitening removes color without introducing chlorine byproducts, so the paper contributes nothing to the cup except filtration.

The 90 gsm weight is a deliberate tradeoff. Lighter papers (60–70 gsm) common in drip formats collapse under the turbulent flow of a percolator cycle and can tear over direct heat. Heavier papers above 100 gsm restrict flow enough to extend brew time beyond the SCA-recommended 4–6 minute window, leading to over-extraction. At 90 gsm, these filters hold structural integrity on a propane burner while allowing the natural coffee oils that produce body and mouthfeel to pass through. The 20-micron rating retains fine grounds without choking the basket (ASTM F838 filter retention testing establishes micron-level retention as the standard measure for filter media performance).

How it compares

How to brew with percolator filter papers

1. Seat the filter. Place one paper flat in the percolator basket before adding grounds. Press the edges down so the paper sits flush against the basket wall with no folds that could bypass grounds.
2. Dose the coffee. Add coarsely ground coffee at a 1:18 ratio — approximately 55 g of coffee per liter of water — per SCA Brewing Standards. For a standard 8-cup percolator (~950 mL), that is roughly 52 g.
3. Set heat and monitor temperature. Bring water to 195–205 °F before the percolation cycle begins. Over a propane burner, this typically takes 4–6 minutes on medium flame.
4. Percolate for 4–6 minutes. Total brew time within the SCA-recommended window produces balanced extraction. Reduce heat once cycling begins to avoid boiling, which pushes water temperature above 205 °F and accelerates over-extraction.
5. Remove and dispose. Lift the basket, allow the filter to cool briefly, then fold and pack out the used paper per Leave No Trace Center pack-out standards for disposable camp consumables.

Care & longevity

• Store unused filters in the original kraft sleeve, resealed after each use. The moisture-resistant lining keeps papers dry in humid pack environments for the duration of a standard multi-day trip.
• Do not pre-wet these filters before brewing. Unlike some drip papers, the 90 gsm weight is stable enough to seat without rinsing, and pre-wetting in the field wastes water without measurable taste benefit at this paper weight.
• Filters are single-use and compostable. Used papers with coffee grounds can be composted at home; in the backcountry, pack them out in a sealed bag per Leave No Trace Center guidelines — do not bury or burn.
• Ridgebrew covers manufacturing defects (tears, inconsistent sizing) on unopened packs. Contact support with your order number; opened packs are covered if defects are present across multiple filters in the same sleeve.

Frequently asked

Q: Will these filters hold up directly over a campfire grate?

Yes. The 90 gsm paper weight is rated to hold shape at percolator operating temperatures (195–205 °F). The filter never contacts flame directly — it sits inside the metal basket, which acts as a heat buffer. Avoid boiling the percolator dry, which can scorch the basket and degrade any paper filter regardless of weight.

Q: What basket sizes do these fit?

These papers are cut for standard 8–12 cup percolator baskets, which cover the most common camp percolator formats including GSI Outdoors Percolator and Stanley Camp Percolator models. They are not sized for stovetop moka pots or drip cone formats.

Q: Can I use these in a drip coffee maker at home?

No. Percolator basket papers are flat-cut discs, not cone or basket shapes designed for drip machines. Using them in a drip maker would require trimming and would likely result in bypass around the edges.

Q: How do these compare to just using no filter in a percolator?

Unfiltered percolator brewing passes fine grounds and sediment into the cup. The 20-micron rating on these papers retains fine particles while allowing oils through, producing a cleaner cup without the silt common in unfiltered percolation. Sediment also accelerates wear on percolator basket screens over time.

Q: Are these OEKO-TEX certified or otherwise tested for chemical safety?

These filters are made from unbleached cellulose processed without chlorine compounds. Ridgebrew does not currently hold OEKO-TEX certification on this product line; buyers requiring certified food-contact documentation should contact Ridgebrew support directly for current testing records.

Q: How many brews does one pack cover?

Each pack contains 100 filters, one per brew. At one brew per day, a single pack covers 100 camp mornings. For a four-person group brewing twice daily on a week-long trip, one pack covers approximately seven trips.

Last updated: 2026-05-12