ASKO - Washing with cold vs hot water

Washing with cold vs hot water

Ever read the labels on your clothing and wondered why it says to wash in hot water? The difference between hot and cold water consists of more than a simple change in temperature, and whether you want to save money, deep clean or remove stains, we’ve broken water temperature down to the three essential things you need to know.

1. Money down the drain

Cold water washes are great for saving money, taking care of fabric, and avoiding setting stains in clothing. Every hot wash requires water to be heated, and the standard washing machine uses a minimum of 75 litres of water per wash. Using a cold wash will save you from pouring dollars down the drain each time your energy bill arrives.

Delicate fabrics like silk and wool are also best washed in a cold water cycle. The fibres in natural materials aren’t as strong as synthetic fibres, and heat can break down their structure, leading to a shorter lifespan. Dyed clothing or linen that have been dyed a dark colour bleed less and keep their intensity in a cold wash, but all fabrics are cleanable in cold water. 

2. Deep down they’re not clean

However, there are some circumstances when only a hot water wash will do. The heat in a hot wash loosens oil and grease and kills germs. Most of the time, cold water is able to effectively clean out the residual dirt caught up in fabric, but for households fighting off bugs, a hot wash is the best way to keep a household free from reinfection. Washing hand towels, face cloths, and bedding in a hot water wash minimises the chances of those bugs spreading around the family and helps to prevent the occurrence of allergy causing irritants like dust mites.

The other factor to consider when choosing between a hot or cold water wash is what kind of dirt is being washed out of clothing. Day-to day-dirt only needs a quick warm wash but an outdoor hike through a muddy field might require a more intense type of heat and more detergent to get the clothes fully clean.

3. Prep for the best results

Stains are the bane of everyone’s laundry experience. How many times have you thrown something in the wash, desperately hoping for the tomato stain to come out? Protein-based stains need a cold water wash to remove their discolouration, while any oil or grease stain needs warm water to lift it from the fabric.

Applying a paste made of laundry detergent as pre-treatment before the wash can also help in stain removal. To prevent a stain from setting, first apply water, keep the garment away from dry heat, and applying the pre-wash solvent on the material behind the stain.

If you want a deep clean but need to wash a temperature-sensitive fabric like wool, the best solution is to do a pre-wash soak in the detergent appropriate for the fabric type. This will give the detergent time to work it’s magic and absorb all the oils and grime, and then when you wash the clothing, the chemical reaction in the surfactant will already have been activated.

Understanding when to use a hot or cold wash isn’t easy, but next time you do a wash, take a moment to look at the settings on your washing machine. The best way to look after your clothes is to know how these cycles work.

If you have a difficult stain you can't get out, you can visit the ASKO Stain Guide