My experience has been that liquid detergent and cool water temps. cause build up in both the machine and clothes. Liquids have ingredients that can build up. Build up can result in mold and stale smelling clothes. I use a mix of both powder and liquids. I find the powders rinse better in my softer water. I never use cold. Last night I did a load of cashmere in liquid detergent and warm, which is about 90 degrees and everything came out clean and zero odors. Powders will not properly dissolve in cold water.

I've been washing in warm and hot since reading this board, I noticed my clothes don't have that stale "stink" anymore, it definitely does make a difference.

Liquid detergent clogged my machine up even when only using hot water. I switched to powder all my clothes are clean and my washer is sparkling.

All powder user here, no mold, no stink, only clean clothes and clean washer. I used liquid in the top loader I used to have and there was a ring of old detergent buildup at the waterline. I always use warm or hot water.

Powders have a higher PH so they are more aggressive at attacking soils. Back many moons ago before synthetic detergents the housewife knew the benefits of raising the wash waters PH...soap just didn't do it which is why soda ash (sodium carbonate) was liberally added.

The higher the PH the better cleaning...however to high a PH and your textiles will pay the price.

Most liquids are close to neutral PH.