Which is the best type of washing machine detergent?

It’s confusing that there are so many different types of detergent available. You’d expect that the best type would have been long since found and win the day so to speak. But as with many things, there are pros and cons for different types of detergent. Knowing what they are means you can make an informed choice about which type of detergent to use.

Washing powder, liquid or tablets?

Detergents Washing powder has been used successfully for decades. If liquid was definitely better then you’d expect powder to have disappeared by now. It hasn’t.

The advantages of liquid are meant to be that the detergent is already dissolved into a solution. So if your normal detergent isn’t being flushed into the drum properly you may find that the liquid is better.

Some powder-based detergent may not dissolve as well in cold water or get properly flushed out of the drawer due to low water pressure. However, I’ve not heard any claims that liquid detergent washes any better than powder. In fact it has disadvantages – so don’t use it unless you need to.

Downsides to liquid detergent

The most important thing to realise about liquid detergent is that it doesn’t contain bleaching agent. It’s therefore kind to coloured laundry and doesn’t fade colours, but not so effective for whites. Bleach also helps to keep the washing machine free from bacteria and black mould.

If liquid detergent is used all the time combined with mostly low temperature wash programmes it can result in serious problems over time. Nasty slime and grease can build up and cause a smelly washing machine. Apart from being annoying, this grease and slime can seriously shorten the life of your washing machine. (Causes of grease, slime and black mould inside washing machine)

Detergent tablets

Detergent tablets are convenient because they contain a predetermined dose. They are mostly a convenience product. The detergent inside isn’t likely to perform better but there’s no measuring out needed and no stray detergent to be spilling around. If the detergent washes just as well they should be better than loose detergent if they prevent under dosing. They are highly likely to cost more to use than loose detergent though.

See best buys & don’t buy reviews on detergents

Join Which? Several Which? Trial Offers available to allow you to research all future purchases and see expert reviews and recommendations. Easily save a lot more money than it costs.

You don’t just use one detergent do you?

washing machine detergent Did you know that although most people buy and use just one type of detergent you should get better results using at least two different types – possibly even three? If you want to use ecological detergent too maybe even four.

Before you decide this article is just trying to get you to use more detergent – it’s not. This is about getting the most effective wash results and the best care for your laundry and washing machine. Apart from the initial outlay of buying and stocking more than one type it shouldn’t really cost more to use different detergents for different jobs.

You wouldn’t use any more, you’d just share the same amount between different types of wash load. It would be no different to buying several brands of coffee for example. You wouldn’t use any more, you would just have more to choose from. The main argument for using more than one type of detergent is that washing whites and dark laundry are two different jobs. They ideally require specialist detergents.

Detergent For whites you need a detergent containing bleaching agents to keep them bright white. You also need this type of detergent for the essential maintenance washes designed to keep your washing machine in good health these days (causes of grease, slime, smells & black mould inside washing machines).

However, detergent containing bleaching agents is not so good for non-white laundry because it can fade the colours.

So, if you only use a detergent that contains bleaching agents, your whites will be lovely and white, but your darks and coloured laundry can fade in colour. Conversely though, if you only use a detergent that does not have bleaching agents then your colours will keep their colour much longer – but your whites will not remain as bright and white, and can start to look dingy and grey.

Liquid detergent does not contain bleaching agents, neither does detergent designed to look after colours in your laundry such as Ariel colour powder

Another tip is that biological detergents should not be used on silks and woollens (see article link below).

Ecologically friendly, or 30 degree wash detergent could also be used occasionally for lightly soiled laundry. It’s early days for them yet and they aren’t so good for heavier soiling, or bedding and underwear etc. but whenever you are just washing something lightly soiled you could use it effectively

Silks & woollens

If you have laundry made of silk to wash or lots of woollens you may need to stock another type of detergent too because some detergents can cause damage to these fabrics – Biological washing machine detergents can damage woollens & silks (cause holes)

Liquid Detergent Tabs Safety Warning

Safety warning about liquid detergent tabs used in washing machines & dishwashers

More on detergents by Which? –

  • Which? 38 washing powder and laundry detergent reviews
  • Which? Best Buy washing powder and laundry detergent
  • Which? Don’t Buy these washing powders and laundry detergents
  • Which? We compare the best and worst to help you find your ideal laundry detergent
  • List of benefits of being a Which? member
Fixed-price repairs, Pay monthly, Repair & protect your whole appliance..
Save money

Subscribe to Which? today and start saving time and money

Various membership options available.

Ransom Spares is a family company with over 1 million spare parts. Next day delivery available, friendly company with over 5000 reviews on Trust Pilot - Buy your appliance spare part

Price match promise: "If you find the exact same part cheaper, we’ll not only match it, we’ll beat it!"

Comments need to be on topic with the article (Moderated before appearing).

2 thoughts on “Which is the best type of washing machine detergent?”

  1. Having used a liquid detergent for about a year & experienced the horrible black mould & slime that built up, I have now returned to using a powder with bleaching agent. So far so good & the whites are much whiter too!

  2. Yes it’s horrible stuff that liquid detergent Carole. Especially if it’s the only detergent used and combined with only using low temperature wash cycles. I wrote this article to warn about that because it never crosses most people’s minds to use more than one type of detergent. Glad you managed to get rid of the horrible gunge and smell.

Comments are closed.

Comments Policy

Comments welcome (unless closed). Comments need to be on topic with the article (Moderated before appearing).

Scroll to Top