Why Are My Pellets Soft or Powdery?
Soft, crumbly, or powdery pellets are the most common complaint on a pellet mill, and they almost always trace back to one thing: the pellet did not get enough moisture, heat, or pressure to bind. The good news is that the fixes are a short list. Here is how to find the cause and correct it.
Start with conditioning
Most soft-pellet problems are conditioning problems. If the mash reaches the die too dry or too cool, the natural binders never fully activate and the pellet leaves the die weak. Bring the mash up to a runnable moisture and temperature before it hits the die.
Under-conditioned mash is the number one cause
Get the mash to a runnable moisture and temperature first. Check your conditioning moisture and confirm your steam is doing its job.
Check your die compression ratio
The die does the pressing. If the compression ratio, the working length of the hole divided by its diameter, is too low for your ration, feed passes through too easily and the pellet comes out soft. A higher ratio squeezes harder and firms the pellet up. Use the die compression ratio calculator to see where your die sits, and read choosing the right die.
Look at fat and binder
Fat lubricates the die. A ration high in added fat slips through with less friction, which softens the pellet, so fat-heavy formulas need a higher compression ratio or a binder to hold quality. A formula short on starch or natural binder will struggle to hold together no matter what you do at the mill.
Grind and worn parts
- Grind too coarse. Coarse particles do not bind or take up steam as well. See hammermill screen selection.
- Worn die or rolls. A polished die or glazed rolls stop gripping and pressing. If the mill has run a long time, a rebuild may be due.
- Rolls set wrong. Rolls that slip instead of pressing make a soft pellet. See setting the rolls.
Confirm it with a number
Do not judge pellet quality by eye. Run a durability test and put a number on it. Our PDI calculator turns a before-and-after tumble into a durability index, and TEKPRO Holmen testers do it right on the floor.
The order to work through it
- Conditioning first. Moisture and temperature fix most soft-pellet problems.
- Then the die. Confirm the compression ratio fits the ration.
- Then the formula. Check fat level and binder.
- Then grind and wear. Screen size, die and roll condition, roll setting.
Chandler Adams reps CPM pellet mills and dies, TEKPRO durability testers, and the conditioning and steam gear behind a firm pellet. Reach out if you want a hand dialing yours in.
Getting the most out of your pellet mill?
Chandler Adams reps CPM pellet mills and the full feed-mill line: dies, rolls, conditioning, and the monitoring gear that keeps it running. If you want a hand dialing yours in, reach out.