Powder vs Liquid Detergent: What Actually Matters

People ask us this a lot on service calls, usually while we have got the machine pulled out from the wall. Powder or liquid? The honest answer is that for a washing machine it is close to the least important choice you make, and for a dishwasher the evidence actually points one way. Here is what the manufacturers and the independent testers say, and where we see people go wrong.
Washing machines: the argument that barely matters
For a front loader, the thing that matters is not powder versus liquid. It is whether the detergent is low-sudsing and whether you are using the right amount.
Front loaders and high-efficiency top loaders use far less water than the old agitator machines, and they clean by tumbling clothes rather than sloshing them. Too much foam cushions that tumbling action and stops the clothes rubbing against each other, so they actually come out less clean. Australian House and Garden makes the same point: pick a detergent labelled "front loader" or "HE", because those are low-suds and more concentrated for the lower water levels.
Both good powders and good liquids come in front-loader formulas. When CHOICE ran 50 laundry detergents through its lab, strong performers and poor performers turned up in both camps. Form is not what separates a good wash from a bad one. Formula and dose are.
Powder has a slight edge on ground-in dirt and mud, which is handy if you have got kids in sport. Liquid dissolves better in cold, quick washes and works well for pre-treating a stain. Pick whichever suits your loads. Just make sure it says front loader on the box if you have got one.
Dishwashers: here the testing is clear
Dishwashers are different, and this is where we will take a side.
CHOICE tests dishwasher tablets, powders and gels the same way every year, and powders keep coming last. In the most recent round the tablets scored between 57 and 80 per cent while the powders ran from 32 to 63 per cent. A good tablet cleans better than the best powder tested.
Powder is cheaper per wash and lets you dial the dose up or down, which is a fair reason to like it. But if you are getting film on your glasses or grit left on plates, a quality tablet is the easiest first fix. Whatever you use, keep the rinse aid topped up so glasses dry clear, and keep an eye on the salt reservoir if your machine has one.
The mistake we actually see
Here is the fault that brings us out more than any detergent brand: too much of it.
Overdose a front loader and it over-suds. The excess foam can leave detergent residue on clothes, stop the machine rinsing properly, and in some machines it triggers a fault code that stops the cycle dead. People then ring us thinking the machine is broken when it is drowning in suds. A machine that has been run too hot on detergent for months also builds up residue in the drawer, the hoses and the door seal, which is where the smells start.
The dose on the box assumes a full, dirty load in hard water. Most Illawarra homes have neither, so if anything you want less than the line suggests, not more.
The short version
Use a front-loader or HE detergent in a front loader, powder or liquid, your call, and use less than you think. In the dishwasher, a good tablet beats powder in the testing, so start there if your dishes are not coming out clean. And measure. More detergent does not mean cleaner.
If you have measured, switched detergent and the machine still throws a code, floods with foam or leaves the dishes dirty, it is a fault, not the detergent. We service washing machines and dishwashers across the Illawarra and South Coast. Book online or call 02 4229 3777.




