You want to buy wood pellets. But how do you know which pellets are of good quality? That is what I wondered when I first wanted to buy pellets for our brand new pellet stove. Once you start searching you will see terms like DINplus, ENplus, other certificates and labels. But to be honest, I could not take it well. Even test purchase could not give me much clarity. This article is an attempt to prevent similar panic moments in others. Once you have read this, you should know exactly what you are looking for, and why.
The best label you can have right now is ENplus A1, and all the best pellet smoker you buy should actually have that label. Forget DINplus, it is no more than a marketing term at the moment, with few real quality guarantees.
What? Did you expect more? Do not you hate when you have to read an entire article to find out the answer in the end? 🙂
But if you want to know more about the quality of pellets now, or what it really makes, or what other labels you may encounter, then definitely read on. In the end we even talk about how you can manually test the quality of pellets.
Why quality and not just price
The price of your bag of pellets will always be extremely important, no one likes to spend more money than necessary. But before you quickly find the cheapest supplier, think about what your pellet stove has cost. And what a hassle it is for a repairman to come by if something goes wrong.
At least as important as the price of your pellets is the life of your pellet stove. And that is why you have to pay attention to the quality of the wood pellets that you buy.
Things like the amount of ash that remains after burning, or the amount of moisture in the pellets, or what residual materials are released during combustion, have a strong impact on your stove.
Quality labels can also refer to the origin of the wood. For example, if you find it important that the wood is extracted locally, and the pellets are produced locally, you can make conscious choices here. Just like whether the wood can come from full trees, or only from wood waste. Maybe not just as important for everyone, but for many (including myself).
Which properties determine the quality
The most important things that are measured to determine the quality of wood pellets are the following:
Amount of ashes released during combustion
The less ash, the cleaner the pellet burns. And the less you have to cleanse the ‘ashtray’. A higher presence of ash when burning can be a sign that there is more bark, moisture or other impurities in the pellet. In order to be ENplus certified top pellet smoker, only 0.7% of the original weight may remain as ash after incineration.
High melting temperature for ash
If your ashes melt too quickly, you will get blocks of molten ash that can cause blockage and the like. For ENplus A1 (the strictest standard), that temperature must be above 1200 degrees Celsius.
Diameter and length of the wood pellet
This surprised me, but apparently the diameter and length is indeed important. Your pellet stove expects pellets with a certain dimension because its effect is adjusted accordingly. If you have many different pellets, this can have consequences in the supply of pellets to the dressing room, it can cause confusion in the internal electronics that calculates how many pellets to feed, and so on.
Pellets for private heating are usually around 6mm (8mm for industrial applications), and maximum 40mm long.
Amount of dust
At the bottom of your bag of pellets you always have a quantity of wood dust and sawdust. This may not be too much or your stove will need more maintenance, and your combustion will not be optimal. It can also cause blockages. For example, I myself have already experienced that the feed screw that drops pellets into the combustion chamber was jammed by piled sawdust, never nice.
For ENplus, your pellets may only contain 1% dust.
Of course, water and fire are not good friends. The lower the moisture content of your pellets, the more heat per kg you will get from your pellets.
The humidity level should not exceed 10%. (ENplus)
The heat emitted by pellets during incineration is measured in kilowatt hours (kWh). Other combustion substances use the same unit of measurement, which makes it easier to compare. For ENplus, the heat emission must be greater than 4.6kWh per kilogram of pellets.
Some more things that are being looked at to determine quality:
- temperature during entire life cycle: according to ENPlus the pellets must not be transported or stored in a place that is warmer than 40 degrees
- sturdiness: when manipulating and carrying bag pellets, there will always be a few pellets breaking apart and creating extra dust, this should not happen too much
- density: the weight of a certain volume of wood pellets must be above a certain value. If not, it means that the wood in the pellets is not compressed enough, which will cause dust and sawdust more quickly
- presence of additional substances: there may only be a very limited amount of zinc, nitrogen, sulfur, chlorine, etc.
In order to arrive at a common standard of quality, certain standards have been set up which, among others, impose certain values and tests for the above properties. The two best known, and most relevant, are DINplus and ENplus.
This is undoubtedly the best known. It was originally a German standard, drawn up by the standardization body DIN Certco. A little later it got a more European character by incorporating standards drawn up by the European Union (EN 14961-2), and even later they even included the worldwide ISO standard (ISO 17225-2).
It is a well-known label, but it has had a huge impact on fraud, which means that DINplus can not be completely trusted anymore. It does not mean that the pellets are bad, but it also does not prove that they are good.
Since that ENplus was released, which contains a more extensive set of specifications, DINplus has become more in the background. For more details visit https://toppelletsmoker.org