Boveda 58% 2-Way Humidity Control Packs 67g

Boveda 67g 58% Humidity Control Packs Hold a Pound Steady Boveda works on a different chemistry from the Integra packs beside it, and the difference is worth understanding. Inside is a saturated solution of food-grade salt, purified water and a food-grade thickening agent, held behind a reverse-osmosis membrane. That membrane releases pure water vapor and nothing else. The salt is what fixes the number. A saturated solution holds a specific relative humidity by physics rather than by adjustment, which is why the accuracy is ±2%. This is the 67 g size at 58% RH, in a 3.5in x 5.25in food-safe kraft pouch, covering up to 1 lb of cured material. No activation is needed; it works from the moment the wrapper comes off. 58% Humidity Packs for Long Term Storage, and What They Are Not A few things this will not do. It will not rescue material that went into the container too wet or too dry, since it corrects slowly and only across a small gradient. It will not hold a number in a container that leaks, because it will simply spend itself against the room. And it is not the same as a salt-free pack, which matters if you object to salt chemistry near your product on principle. What it does do is hold 58% RH within two points for months, without a hygrometer and without any intervention. 58% is the drier end of the range, aimed at long holds and denser material rather than at jars that turn over weekly. For those, 62% keeps more moisture in the material. The pack is spent when it turns rigid, and at that point it is replaced rather than recharged. Boveda makes the 67 g size as singles and in bulk cases, so the format follows the quantity you need. Key Features 58% RH Two-Way Control: Adds or removes moisture to hold the setpoint, rather than only drying the container out. Accurate Within 2%: Holds the setpoint within two points in an airtight container. Covers Up To 1 lb: Boveda's large-container size, matched to gallon jars, canisters and pound barrier bags. No Activation Needed: Pull the overwrap, drop it in, close the container. Equilibration takes 24 to 48 hours. Turns Rigid When Spent: Replace when it feels hard all the way through, not when the corners firm up. Pure Water Vapor Only: A reverse-osmosis membrane passes vapor, so the salt solution stays inside the pack. Individually Overwrapped: Sealed until opened, so an unused pack keeps its full 2 year shelf life. Food-Safe Construction: Food-grade salt, purified water and thickener, in food-safe kraft paper with food-safe inks. 3.5" x 5.25" Format: Lies flat across the top of a large jar or bag instead of taking up usable volume. Use the Largest Pack That Fits: Boveda's own guidance: more reserve holds RH more stably than several small packs. Technical Specifications Specification Value Brand Boveda Pack Size 67 gram (Boveda Size 67) Relative Humidity 58% RH RH Accuracy ±2% Humidity Control 2-way (adds and removes moisture) Coverage per Packet Up to 1 lb (about 450 g) of cured material Packet Dimensions 3.5" x 5.25" Composition Food-grade salt, purified water and a food-grade thickening agent Membrane Reverse-osmosis membrane; releases pure water vapor only Exterior Food-safe kraft paper with food-safe inks Activation None required Equilibration Time 24–48 hours to bring a sealed container to setpoint Individual Overwrap Yes — each packet sealed until opened Humidity Indicator Card Not included — Boveda uses a tactile rigidity check instead Replacement Signal Replace when the pack is rigid all the way through Suggested Interval About every 3 months as a rule of thumb In-Use Life Typically 2–4 months; as little as 2 weeks in a frequently opened container Shelf Life (overwrapped) Up to 2 years in the original sealed wrapper Intended Containers Large jars, canisters, curing containers and pound barrier bags Alternate RH in This Size 62% RH Part Number MB58-67-OWB Sold As Single individually overwrapped packet UPC 852715006347 SKU MB58-67-OWB How Do You Know When a Boveda Pack Is Spent? It turns rigid. Boveda's test is whether it feels hard all the way through; firm corners with soft spots elsewhere mean it is still working. Should You Run 58% or 62% RH? 58% for humid rooms, long holds and material cured on the wet side. 62% holds more weight and aroma for anything moving to a customer soon. Does a Boveda Pack Need Activating? No. Pull the overwrap and put it in a sealed container. It brings the headspace to setpoint over the next 24 to 48 hours. How Much Does a 67g Pack Cover? Up to a pound. The 8 g covers an ounce, the 4 g a half ounce, and the 320 g steps up to five pounds.