Biological detergents have enzymes that boost cleaning power. Best for stain removal but not suitable for frequent use on silk or wool.
Non-biological detergents does not contain enzymes and is thought to be kinder to sensitive skin.
Powder detergents tend to be best at stain removal and are the cheapest.
Liquids are more expensive but handy to pre-treat stains.
Capsules are convenient but cost more and occasionally don't dissolve.
White cottons gone grey?
Rewash using maximum dose of detergent on the highest temperature recommended on the label. If that does not help, soak in a bleach solution and rinse through.
Source: Feature in Good Housekeeping, February 2019
