Skip To Content

    9 Things Everyone Needs To Know About Bath Bombs

    1. The fresher they are, the faster they fizz.

    Rebecca Hendin / Laura Gallant / BuzzFeed

    Bath bombs are pretty fucking dreamy.

    And they make taking a bath like swimming in a painting.

    So we asked the experts at Lush about everything bath bomb–related, from how to store them to how to get the colours to ~swirl~.

    1. "Do bath bombs expire?"

    Laura Gallant/BuzzFeed

    Bath bombs will get less effective as time goes on. The fresher they are, the faster they'll fizz, says Jack Constantine, head of product development at Lush.

    "We have fanatics who'll keep theirs wrapped and in tupperware boxes underneath their bed, for years – which is extreme," he says. "But you can do it, as it's about the freshness. If the bath bombs are out on display, they're oxidising and they're losing the ability to react so well. So the citric and the bicarb start to bind. The fresher they are, the faster they fizz.

    "Our freshness policy in the factory is 21 days. So if you buy off the website, it's normally seven days at a push [i.e., your product has been made within seven days]. We will get complaints from people who say, 'I bought this a year ago, I chucked it in and it did nothing!' You need to use it. The same with the smell – the smell will wear off as all the essential oils start to evaporate."

    2. "How long should I leave my bath bomb before getting in the bath?"

    Laura Gallant/BuzzFeed

    A layered bath bomb will take about five minutes to fizz to completion, Jack says.

    "Where you have one mix in the centre that's bursting to get out, once the mix finds a hole, that starts propelling it," he says. "But it finds a hole in different places, so every time you chuck it in, it'll be different. You'll never get the same thing.

    "The best thing with those kind of bath bombs is to not get in. Fill your bath, chuck it in, and wait five minutes. And then watch it, then get in."

    3. "How do I make the colours of my bath bomb swirl?"

    Laura Gallant

    The chemical reaction between bicarbonate of soda and citric is what makes your bath bomb fizz and move across the tub, according to Lush digital lab assistant Rachel Lake. One mixture is faster than the other, so by combining the mixture in certain ways, the inventors can control the flow of the bathbomb.

    "The colours start to swirl and move around because of the chemical reaction between the bicarb and the citric," she says. "When that fizzes in the water, the bomb can turn around – say if you put a bubble mix on one side, and a ballistic mix on the other, that's going to push it."

    Jack adds: "For example, we can force the mixes to go in different directions. We can control the flow of the bath bomb. There are patents on these two separate mixes that we use, and when we combine them one's faster than the other."

    4. "How do I get glitter off my bathtub?"

    Laura Gallant/BuzzFeed

    "Wash it!" Jack says. "Bath bombs, especially the ones I work on, have a mix that has some surfactants in it. That helps to remove it from the edges, naturally. But if it's getting stuck on there, we always suggest a shampoo bar, or a shower gel, whatever."

    Surfactants are compounds used as foaming agents, detergents, and emulsifiers. "You don't need serious toilet products to clean it," he says. "Anything with a little bit of surfactant in it will just wash it off. The same with the colour – often we'll get concerns like, 'Oh, you've stained my bath.' But if you just use a product with surfactants in it, it'll come straight off."

    5. "Can I wash my hair if I've got a bath bomb in the water?"

    Laura Gallant/BuzzFeed

    "It's not going to negatively affect your hair," Jack says.

    "But there are now ingredients in your bath – like essential oils, there's some citric acid. They're not bad – these ingredients are softening, for example. But it will mean it will have a different effect. And if it's a bath bomb with surfactant in, for example, then it's going to clean you anyway, because that's what surfactant does."

    6. "Can I use a bath bomb if I have sensitive skin?"

    Laura Gallant/BuzzFeed

    "In general, they're all really mild," Jack says. "Nothing in there is going to irritate you, but if you're really sensitive, avoid the ones with loads of layers of bubbly mix.

    "The original bath bomb formula is surfactant-free, so it doesn't have anything that can affect your skin. It's effectively the softest formula, so it doesn't irritate. But then when you start to add bubble mix, there's the potential for irritation.

    "If you use things like Butter Ball or Big Blue, then you'll get a lovely bath that's not going to irritate you at all."

    7. "What is lustre? Why don't you use glitter?"

    Laura Gallant/BuzzFeed

    "The glitters we used in bath bombs were based on plastic," says Simon Constantine, Lush's head perfumer and head of ethical buying. "And so a couple of years ago, we were quite rightly pulled up by our customers. In terms of microplastics and them washing up into the ocean, glitters are not biodegradable. And especially as it's a bath product, it's not as if you can recycle it.

    "So then we started to research and see if we could move away from that and we went to lustres, which are vegetable-based."

    8. "Are there any secret bath bomb projects on the cards?"

    Laura Gallant/BuzzFeed

    Lake says: "Because we haven't done it yet, I'd love to turn the water a little bit jelly-like. Not so much like you're stuck in jelly, just changing the texture of water. I think that would be really cool."

    9. "Is it possible to make a customisable bath bomb?"

    Laura Gallant/BuzzFeed

    The only problem would be logistics, Jack says: "We would need an army of staff just making customised bath bombs!

    "In theory it would be amazing to provide some kind of personalised, customisable service. It's just the realities of how we could work that. I think we could provide a similar service digitally, like where you can customise your trainers etc – we could look at the ways it could work and provide options, like mix this fragrance with this one and so on.

    "It's just about the batch. To make a single item, it's like, 'Yeah you can have it, but it will cost you £100!'"