How to Store Wood Pellets the Right Way (Bags and Bulk)
You’ve bought a full season’s supply of premium wood pellets. Now comes the part many people overlook: storing them. Wood pellets are made by squeezing dried sawdust until it’s very dense and dry — and their biggest enemy is moisture. Store them badly and those high-performance pellets can swell, crumble into sawdust and jam your stove.
Here’s how to store pellet bags and bulk pellets so every last one burns as well as the first.
Why moisture is the enemy
Quality pellets typically leave the factory with under 8–10% moisture. Wood fiber naturally wants to absorb water from the air, and once pellets get wet they:
- Swell and break apart into sawdust (“fines”)
- Burn cooler and smokier, wasting heat
- Jam augers and clog burn pots
- Can grow mold if left damp
Even high humidity, without direct water contact, can soften pellets over weeks.
Storing bagged pellets
1. Keep them off the floor
Concrete floors wick moisture from the ground. Always store bags on wooden pallets, plastic pallets or shelving at least a few inches (10 cm) off the floor.
2. Choose a dry, covered location
Good options include:
- An attached garage
- A dry basement (use a dehumidifier if needed)
- A ventilated shed with a solid roof
- A covered porch with a waterproof tarp
Avoid storing pellets outdoors uncovered, against damp exterior walls or under leaking roofs.
3. Leave the original plastic wrap on
Pallets usually arrive shrink-wrapped with a hood. Keep that wrap on until you need the bags. If you must store outside briefly, add a heavy-duty tarp that covers the top and sides but allows air to circulate underneath.
4. Don’t stack too high
Heavy stacks can crush the bottom bags and create fines. If you re-stack by hand, keep layers stable and interlocked, the way they arrive from the supplier.
5. Inspect damaged bags first
Use torn or punctured bags first. Tape small holes immediately to keep humidity out.
6. Keep pests out
Pellets aren’t food, but mice love nesting in warm, dry stacks. Keep the area tidy and sealed.
Storing bulk pellets
If you heat with a pellet boiler, you may receive pellets by blower truck into a storage room, fabric silo or outdoor silo.
Fabric silos and bags are popular in basements and garages. They’re quick to install, keep pellets clean and allow dust to escape through the fabric.
Dedicated storage rooms need dry walls, a sloped floor that feeds the extraction system, and an impact mat opposite the filling pipe so pellets don’t shatter during delivery.
Outdoor silos must be completely waterproof and properly sealed at all joints.
Important safety note for bulk storage
Freshly made wood pellets can release carbon monoxide (CO) as they age, especially in large, enclosed storage rooms with poor ventilation. This is a well-documented issue in Europe, where bulk pellet storage is common.
- Always ventilate a bulk storage room before entering.
- Never enter a closed silo or storage room alone.
- Install a CO detector near storage and heating areas.
- Follow the ventilation guidance from your boiler manufacturer and local regulations.
How long can you store wood pellets?
Stored properly — dry, off the ground and protected from humidity — wood pellets can last several years without losing quality. Pellets don’t “expire”, but poorly stored pellets can degrade within weeks. Rotate your stock so the oldest pellets are used first.
Signs your pellets have absorbed moisture
- Bags feel soft or lumpy
- Pellets break apart with light finger pressure
- A layer of sawdust has formed in the bag
- A musty smell
- Your stove struggles to ignite or produces dark smoke
If only a few bags are affected, mix them in gradually with good pellets or discard badly damaged ones. Never try to dry wet pellets in an oven or near an open flame.
Storage checklist
- ✔ Pallets or shelving under every stack
- ✔ Dry, covered area with low humidity
- ✔ Original shrink-wrap intact until use
- ✔ Damaged bags used first
- ✔ Bulk storage ventilated with a CO detector installed
- ✔ Oldest stock used first
Frequently asked questions
Can I store wood pellets outside?
Only for short periods and only if they are fully protected. Keep the pallet off the ground, leave the factory shrink-wrap intact and cover the top and sides with a heavy waterproof tarp, while allowing air to circulate underneath. For long-term storage, a garage, shed or dry basement is much safer.
Can I store pellets in a basement?
Yes, if the basement is dry. Many basements become humid in summer, so a dehumidifier is a good investment. Keep bags on pallets, away from walls that can sweat, and never store pellets next to the furnace, water heater or other heat sources without the clearances your manufacturer recommends.
Should I store pellets in plastic bins?
Sealed plastic bins or metal cans with lids are great for keeping an opened bag dry near the stove, and they also keep out pests. Just make sure the pellets are dry when they go in, and avoid storing large quantities in airtight containers in enclosed rooms without ventilation.
Does cold weather damage pellets?
No. Freezing temperatures don’t harm pellets. The danger in winter is snow, condensation and moisture tracked indoors, so keep bags covered and bring in only what you need for a few days.
How do I know how many pallets fit in my garage?
Measure the floor space. A standard North American pallet takes about 40 × 48 inches, and a European pallet about 80 × 120 cm. Leave walkways so you can rotate stock and inspect the bags.
Start with pellets worth protecting
Proper storage protects your investment — but it starts with good pellets. Our hardwood heating pellets and softwood heating pellets are delivered in sealed, palletized bags ready for storage. We supply homes, farms and businesses across the USA, Canada and Europe.
Contact Pure Biofuel Pellets to plan your next delivery.
