Citric acid is one of the most versatile and eco-friendly ingredients you can keep in your natural cleaning toolkit. This safe, biodegradable compound is highly effective at breaking down limescale, soap scum, and hard water stains. Thanks to its acidic nature, citric acid is powerful enough to tackle stubborn build-up yet gentle compared to harsh chemical cleaners. It’s the perfect choice for anyone aiming for a sustainable home without compromising on results.
Why I Love Using Citric Acid in DIY Recipes
In my cleaning recipes, citric acid shines as a true hero ingredient.
- Dishwasher Rinse Aid – If you haven’t tried this one yet, you’re missing out! Even if DIY Dishwasher Tablets aren’t your thing, this rinse aid is a game-changer. It’s cheaper, kinder to the planet, and every bit as effective as store-bought versions.
- Toilet & Shower Cleaner – This recipe could very well be the best bang for your DIY buck! Citric acid dissolves set-in brown staining in toilets and makes quick work of shower limescale and soap scum. The best part? No toxic fumes, no neon-blue liquids – just sparkling clean surfaces.
Citric acid proves again and again that natural solutions can outperform chemical-laden commercial products.
Where Citric Acid Comes From
There’s often chatter online about the origins of citric acid, so let’s clear that up.
These days, most citric acid is produced by fermenting sugars using a common mould called Aspergillus niger (source). During this process, the mould consumes the sugar and produces citric acid as a by-product. Once the fermentation is complete, the citric acid is carefully separated, purified, and crystallised into the powder you buy.
It’s worth noting that while the starting point involves mould, the final product is highly purified and free from mould residues, making it safe for the vast majority of people (even those with mould sensitivities).
Historically, citric acid was extracted directly from citrus fruits – hence the name – but this method is no longer common because it simply can’t keep up with global demand. The fermentation method is far more efficient and sustainable.
Interestingly, around two-thirds of the world’s citric acid is actually used in the food and beverage industry. It works as a preservative by slowing the growth of yeast, mould, fungi and bacteria, while also acting as a flavour enhancer, antioxidant, and providing that familiar sour taste.
👉 Tip: Always buy citric acid from a reputable supplier to ensure quality and purity. Its affordability and availability make it a true staple in DIY cleaning, plus it helps reduce plastic waste from commercial products. I have a list of suppliers for you to check out, here.
Beyond Cleaning
Citric acid isn’t just for tackling soap scum and hard water marks. I also love using it in DIY bath bombs and fizzies, where it combines with bicarbonate of soda to create that fun, fizzy reaction in water. Check out my Bath Fizzies recipe here.
Final Thoughts
By incorporating citric acid into your cleaning routine, you’re choosing an environmentally conscious solution that’s tough on dirt but gentle on your home and health. While its mould-based origins may sound concerning at first, I do believe that purified citric acid is far safer than most conventional cleaning chemicals. It’s cheap, effective, and versatile – and once you start using it, you’ll never look back.
