Why does my blender leave lumps or unevenly blended ingredients?

If your blender leaves lumps behind, the issue is often the recipe, the batch size or the way the ingredients are loaded. This is usually a performance issue rather than a fault, but you should stop using the appliance if the blades are damaged, the jar is leaking or the motor sounds strained.

1. Check the ingredient order and cut larger items into smaller pieces before blending. Expected result: smaller, evenly sized pieces should move more freely around the blades.
2. Add liquid where appropriate and avoid overfilling the jar. Expected result: the ingredients should circulate rather than sit in layers.
3. Use short pulses first, then blend continuously if needed. Expected result: the mixture should become smoother after a few cycles instead of packing tightly at the bottom.
4. Scrape down the sides only when the blender is switched off and unplugged. Expected result: stubborn pieces near the wall should be brought back into the blade path.
5. Check whether the blades turn freely and look undamaged. Expected result: the blade assembly should not wobble, drag or appear bent.

If the result is still uneven after a few small batches, or if the motor struggles, stop using the blender and contact the retailer or store where it was purchased. The BL-4431 has two speed settings and removable blades, so correct ingredient preparation and a secure blade assembly make a noticeable difference.