Although sitting by a fire can be incredibly relaxing, especially on cold nights, nothing ruins that relaxation more than having to add wood to the fireplace constantly. Thankfully, you can use a variety of ways to make the wood burn more slowly. The key is using softwoods and hardwoods, both of which need to be completely dry before burning.
Dry, or season, your wood for a year after splitting or purchase seasoned wood. Freshly cut wood is still wet, even if it looks or feels dry, and therefore will not burn efficiently. To speed up drying time, split open larger logs and let them sit in a well-ventilated area for six to 12 months. If you are purchasing firewood, avoid large logs that have not been split.
Inspect your wood before burning it. Dry, seasoned softwood and hardwood logs will be lighter in weight than they look, dark brown and slightly cracked around the edges. Any green on the log indicates freshness, and it won't burn correctly in your fireplace.
Start your fire with softwoods such as spruce, pine or fir, with your chimney damper fully open. Some people avoid softwoods as they burn too quickly, which may seem counterproductive when trying to make your wood burn slower in a fireplace. But you want your initial fire to be as hot as possible so hardwood added later burns effectively.
Add more softwood to the fire until you have a decent amount of hot coals. Add two to three larger hardwood logs on top, keeping a small amount of space between each to ensure adequate air circulation.
Close your damper halfway about 30 minutes after placing hardwood logs on the fire. This allows for plenty of air to prevent smoking or extinguishing your fire while keeping it from burning too quickly.
Stir the coals at the bottom periodically so the main logs are kept hot. Add one to two logs at a time to maintain your fire.