I didn’t switch to shampoo bars because I read a convincing article about them. I switched because the liquid shampoos I was using weren’t working, the good ones cost too much, and I kept consuming plastic packaging at a rate that bothered me. The bars were a solution to several problems at once.

That said, “just use a bar” is not universally useful advice. Bars and liquid shampoos are genuinely different in ways that matter depending on your hair type, your household, and how you want to spend your time and money. This article works through the real comparison, including the parts that don’t automatically favour bars, so you can make an informed decision rather than a fashionable one.

What we’re actually comparing

There are a few different versions of this comparison worth separating out before we start.

Commercial liquid shampoo is what most people are switching from. Bought in a bottle, used until empty, replaced. Ranges from budget supermarket options to expensive salon or “natural” formulations.

DIY liquid shampoo is a less common option but worth acknowledging. It’s possible to make your own liquid shampoo at home using similar surfactant ingredients to a syndet bar. The catch is that any product containing water requires a properly tested preservation system to prevent bacterial and mould growth. That adds complexity, specific ingredients you may not already have, and a formulation step (pH testing) that solid bars don’t require. It’s doable, but it’s a more involved starting point than a solid bar.

Syndet shampoo bars are what Batch and Bubble is built around. Solid, lye-free, formulated around gentle surfactants, and made using a melt-and-mix process that doesn’t require preservatives because the finished product contains no free water. More on what a syndet bar actually is here. And more on solid shampoo bars in general here.

The comparison below is primarily between commercial liquid shampoo and homemade shampoo bars (syndet), because that’s the switch most people are actually making.

Cost of syndet bar vs liquid shampoo

This is where bars win most convincingly, particularly when you’re making your own.

I was spending around $20 on a 250ml tube of natural liquid shampoo every three weeks or so. That’s roughly $347 a year, for a product that never really worked as well as I wanted it to. My homemade syndet bars cost approximately $2.80 per bar in ingredients when bought in bulk. One bar lasts two people about a month with regular use. The annual cost per person is around $17.

Even if you’re not making your own, a commercially produced syndet bar typically costs $15 to $25 and lasts longer than a comparably priced bottle of liquid shampoo because there’s no water content to dilute the active ingredients. You’re paying for surfactant, not water. The full cost and longevity breakdown is here if you want the numbers in detail.

One practical thing I’ve noticed since switching: waste is lower than I expected even within a single wash. With liquid shampoo, some always dripped from my hand directly to the shower floor before reaching my hair. With a bar you swipe it directly over the hair, so nothing goes to waste between the product and the application. It’s a small thing but it adds up across hundreds of washes.

Plastic and packaging

A standard liquid shampoo bottle is single-use plastic. Even “recyclable” plastic has a limited number of cycles before it becomes landfill, and a meaningful proportion of what we put in recycling bins doesn’t actually get recycled.

My household was going through roughly one bottle or tube of shampoo per month. That’s twelve bottles a year from one household, for one product. As the kids transition from their current liquid supply to bars, that number will increase further before dropping to close to zero.

A syndet bar has no plastic packaging by default. It can be wrapped in paper, stored unwrapped, or packaged minimally. The ingredients arrive in larger quantities that produce many bars, so the packaging-per-wash ratio is dramatically lower than individual bottles even accounting for the ingredient containers.

This isn’t an argument that bars are inherently virtuous and liquid shampoo is inherently wasteful. It’s a straightforward observation that the packaging footprint is genuinely different, and for anyone who finds that footprint uncomfortable, bars are a more practical solution than trying to find liquid shampoo in sustainable packaging.

Performance and hair type

Liquid shampoos have one significant formulation advantage over bars: water. Because they’re already in solution, the surfactants activate immediately on contact with wet hair. There’s no melt phase, no cure time, and the formula can be precisely pH-adjusted before it reaches a consumer.

Syndet bars close most of this gap. A well-formulated syndet bar, used correctly on wet hair, produces comparable cleansing results to a good liquid shampoo. The lather is real, the cleanse is thorough, and the pH sits close enough to hair’s natural range that cuticle disruption is minimal. If lather is a concern, this article covers what affects it and how to fix it.

Where liquid shampoo still has an edge is in formulation specificity. Commercial liquid shampoos for colour-treated, chemically processed, or very dry hair can be very precisely targeted. Bars in these categories exist but the range is narrower, and if you’re making your own you’ll need to do some formulation work to get there.

For oily and normal hair types, a well-made syndet bar matches or exceeds most liquid shampoos in everyday performance. For very dry, damaged, or colour-treated hair, a bar is still a viable option but may require more formulation attention to get right.

If you’re formulating for thinning hair, read more here.

Hard water is worth mentioning here too. Traditional soap-based bars perform poorly in hard water. Syndet bars are significantly less affected. If hard water has previously made bars feel waxy or ineffective for you, syndet is worth trying before concluding that bars don’t work for your hair. More on that here.

If you want to find out which formulas suit your hair type, take the Batch and Bubble hair type quiz here:

Storage and shower practicality

This is an area where bars have practical advantages that don’t get discussed enough.

Liquid shampoo in the shower needs a container. The original bottle is the obvious choice, but once it’s empty and you’re decanting into a reusable container, the options get complicated quickly. Plastic bottles are the default but contribute to the packaging problem. Glass looks beautiful and feels premium but a dropped glass bottle in a wet shower is a genuine safety issue, particularly in a shared bathroom. Metal containers are durable but can dent and have been known to crack tiles when dropped. Pump bottles clog. Flip-top lids fail. Bottles left open invite contamination.

I thought through all of this before making the switch and the logic largely made the call. There was no obviously good reusable container solution for liquid shampoo in a shower that was also safe, practical, and didn’t introduce new problems.

A bar sits on a draining soap dish or tray and dries between uses. It doesn’t spill, leak, pump, clog, or run out in the middle of a wash without warning. It’s significantly less likely to cause a problem if dropped. The full guide to storing a shampoo bar correctly is here.

In a shared bathroom with five people, everyone takes their own products in and out of the shower rather than leaving them there permanently. Bars are easier to manage this way than bottles. They sit on the windowsill on a draining tray between uses, take up less space than the equivalent number of bottles, and there’s nothing to knock over.

Kid safety and family use

This is specific to households with children but worth raising directly.

A glass bottle in a shared shower used by children is a risk that’s easy to underestimate. Kids are less careful than adults with wet surfaces. An ADHD child who is already prone to absent-mindedness in a shared shower space is a particular consideration. The consequences of a broken glass bottle in a wet shower are significant enough that the practical argument against glass containers is straightforward.

Bars sidestep this entirely. A dropped bar is a dropped bar. It doesn’t shatter, doesn’t spill, and doesn’t create a hazard. For family bathrooms specifically, the safety profile of a bar is meaningfully better than a glass or heavy metal container.

There’s also a novelty advantage for kids making the transition. A bar is a different enough format from what they’re used to that the switch tends to be met with curiosity rather than resistance. My kids haven’t made the full switch yet but they’re both involved in outdoor activities that include camping, where the portability and packaging-free format of a bar is a genuine practical advantage. Getting comfortable with bars at home sets them up well for that context.

Transition

Switching from liquid shampoo to a syndet bar can involve an adjustment period. It’s shorter and milder than the adjustment associated with traditional soap-based bars, but it’s real. The scalp recalibrates its oil production over two to four weeks, and hair may feel different during that time.

For some people the transition is barely noticeable, particularly if they were already using a gentle liquid shampoo without silicones. For others, particularly those coming from heavily silicone-conditioned products, the first few weeks can feel like a step backward before they feel like a step forward.

The full transition period guide is here with week-by-week detail and the things that genuinely help speed it up.

If you have a sensitive scalp, this article covers what to use and what to avoid.

Making your own vs buying a bar

If you’ve decided bars are worth trying, you have two options: buy one or make one.

Buying is the lower commitment starting point. A good syndet bar from a reputable maker costs $15 to $25 and tells you within a month whether bars work for your hair before you invest in ingredients and equipment. Here’s what to look for on the label.

Making your own costs more upfront in equipment and and bulk ingredients but drops the per-bar cost dramatically. At $2.80 per bar with ingredients bought in bulk, the economics are compelling from the third or fourth batch onward. You also get full control over the formula, which matters for hair types that don’t suit off-the-shelf options.

The other thing making your own gives you is understanding. When you know what’s in your bar and why each ingredient is there, you can adjust the formula for your hair type, troubleshoot problems confidently, and develop variants for different members of your household. That’s a different relationship with your haircare than picking a bottle off a shelf and hoping it works. I’ve already done this – the normal hair formula is here.

The beginner syndet shampoo bar recipe is here if you’re ready to make your first batch. It covers everything from the ingredient list to what the finished product should look and feel like. And if you’re wondering if shampoo bars are even good for your hair, this article has you covered.

Or for full routines including shampoo and conditioner bar formulas check out:

• Dry hair routine
• Normal hair routine
• Oily hair routine

The honest summary

Syndet bars win on cost, packaging, storage safety, portability, and waste reduction. They’re competitive on performance for most hair types and truly better than traditional soap-based bars in hard water. The transition period can be real but is definitely manageable, particularly with a syndet bar rather than a soap-based one.

Liquid shampoo retains an edge in formulation specificity for damaged or chemically treated hair, and in the zero-transition convenience of a format most people have used their whole lives.

For most people washing normal to oily hair with no significant chemical processing, a well-made syndet bar is the better option on almost every practical measure. The main reason more people haven’t switched is familiarity, not performance.

Ready to try making your own? The beginner syndet shampoo bar recipe is the place to start. Or if you’re troubleshooting a bar that isn’t working as expected, download the free guide.

Written by Neets at Batch and Bubble
DIY personal bathroom care recipes for real life.
www.batchandbubble.com