When you’re selecting firewood, knowing the hardness can help you predict how it will burn. Harder woods generally burn hotter and longer, making them more efficient for heating. While professional tests and fancy tools exist, you don’t need specialized equipment to get a good idea of your wood’s hardness. A few simple at-home methods can give you enough insight to choose the right logs for your fireplace or stove.
Check the Wood Species
The easiest starting point is to identify the type of wood you have. Each species has its own typical hardness level—oaks, hickories, and locusts are famously hard, while poplar, pine, and aspen are much softer. Learning to recognize wood by its bark, grain pattern, and color sets a baseline. If you know the species, you can find general hardness rankings online, giving you a quick reference before you test further.
Use a Nail or Screwdriver
A simple penetration test can offer clues about hardness. Lightly press a nail, awl, or screwdriver tip into the end grain of the log. On harder woods like oak or maple, the tool will barely dent the surface. Softer woods let the tool sink in more easily with gentle pressure. While this test isn’t scientific, it provides a real-world indicator of how dense and hard the wood is.
Compare Weight
If you have two pieces of similarly sized, seasoned firewood—one known to be from a hard species and the other unknown—compare their weight in your hands. Hardwoods generally feel heavier for their size due to denser cell structure. If your mystery piece feels notably lighter, it’s probably on the softer side. This comparison won’t give you an exact hardness number, but it’s a quick way to gauge relative density.
Perform a Simple Scratch Test
Take a pocketknife and lightly run it along the surface of the wood. Harder wood resists the blade and produces fine, minimal shavings. Softer wood scratches deeply and easily, sometimes peeling off noticeable layers. Be careful not to dig in too hard, as you only need gentle pressure to see how readily the wood’s surface gives way.
Listen to the Sound
This might sound a bit unorthodox, but tapping the log can reveal something about its density. Tap two pieces of wood together or strike the log lightly with a solid object. Hardwoods often produce a sharper, more resonant “ring,” while softer woods make a duller, more muted sound. Over time, you’ll train your ear to recognize these subtle differences.
Observe Splitting Behavior
If you have the chance, splitting the wood can also tell you a lot. Harder woods often feel more resistant to your axe or maul and might require extra force. Softer woods split more easily and don’t offer the same resistance. While this method takes more effort, it’s a direct measure of how tough the wood’s fibers are.
Combine Multiple Methods
No single test will give you a perfect hardness rating, but using several methods together can build a consistent picture. Identify the species if possible, check the wood’s resistance to pressure with a nail or knife, compare its weight to known hardwoods, and listen to the sound it makes. The more indicators you gather, the more confident you’ll be in your assessment.
Why Hardness Matters
Testing hardness at home helps you plan for how the wood will burn. Harder woods burn longer and hotter, making them ideal for heating during cold seasons. Softer woods catch fire more easily and are great for starting a blaze, but they tend to burn through faster. By knowing what you’re dealing with, you can mix and match your firewood types for maximum efficiency and comfort.