How to make fish soap in a bag?

There is something oddly satisfying about turning a simple skein of cotton into a functional bath accessory that brings a smile to everyone who sees it.

I still remember the giggle of my niece when I handed her a bar of soap dressed as a goldfish, sparking my deep love for functional, whimsical knitting.

My Journey with the Fish Soap Cozy

My adventure with the fish soap bag began years ago when I was looking for a way to use up leftover cotton yarn from dishcloth projects. I wanted something that was quick to knit but had more personality than a simple square, and the idea of a “soap saver” fascinated me.

These little pouches are designed to hold a bar of soap, acting as a washcloth and a way to use up those tiny slivers of soap that usually go to waste.

Lisa Mandel

I remember sitting on my porch with a tangled mess of orange yarn, trying to figure out how to shape a mouth that wouldn't let the soap fall out.

The first few attempts were, frankly, laughable; one looked more like a deformed sock than a fish because I hadn’t mastered the rate of decreases for the tail.

However, once I understood the geometry of the increases for the head and the drawstring mechanism of the tail, it became an addiction. There is a unique rhythm to working with cotton that differs from wool, requiring a bit more muscle but offering a sturdy, satisfying finish.

“The true beauty of a handmade home item lies not just in how it looks, but in how beautifully it performs its daily task.”

Over the years, I have refined my pattern to ensure the fins don’t flop and the eyes stay secure during vigorous scrubbing. It has become my go-to project for palate cleansers between complex sweaters, grounding me back in the simplicity of knit and purl.

Sharing this process feels like passing on a secret recipe—it is simple ingredients combined to make something delightful.

What This Craft Really Entails

Creating a fish soap bag is essentially a small-scale knitting or crochet project that combines shaping techniques with practical design. In the fiber arts community, you might hear these referred to as “soap sacks”, “scrubby bags”, or “soap cozies”, but the fish shape adds a layer of sculptural fun.

Technically, it involves creating a hollow tube that tapers at one end for the head and flares at the other for the tail.

The craft relies heavily on understanding how to manipulate fabric width through increases and decreases to create organic curves. Unlike a flat scarf, you are building a 3D object that needs to house a solid item, so sizing and negative ease are crucial concepts here. It is an excellent entry point for crafters who want to try “in-the-round” knitting using double-pointed needles or the magic loop method without committing to a sock.

Have you ever wondered why your washcloths get soggy and smell after a day?

This craft addresses that by using breathable stitches that allow airflow, letting the soap dry out between uses. It bridges the gap between toy making (amigurumi) and utility knitting, offering the cuteness of a plushie with the utility of a sponge.

Historically, soap savers were a Depression-era necessity to ensure not a single flake of soap was wasted, but today they have evolved into eco-friendly statements against plastic body wash bottles.

While I focus on the knitted version, this can also be done via crochet, though I find knitting produces a softer fabric for the skin. It is best suited for high-beginner to intermediate crafters who are comfortable reading a pattern and managing tension. It is less intimidating than garment making but teaches the same foundational skills of shaping and finishing.

Essential Materials and Tools

The success of this project hinges entirely on the fiber you choose; synthetic fibers simply do not work for this application. Below is the specific breakdown of what I use in my studio for professional-quality results.

I recommend sticking to these guidelines to ensure your fish is absorbent and durable.

Key Techniques and Skills

To construct a fish that actually looks like a fish and functions well, you need to master a specific set of maneuvers. These techniques form the backbone of the project and are transferable to many other fiber arts endeavors. Don’t be intimidated; they are just fancy ways of adding or removing stitches.

• Casting on in the round: Essential for a seamless finish that won’t irritate the skin during washing.
• Make 1 Left/Right (M1L, M1R): These increases create the widening shape of the fish body without leaving gaping holes.
• Knit 2 Together (K2tog) & SSK: The directional decreases used to shape the tapered nose and the tail fins.
• Eyelet Rows: Creating a row of holes (yarn over, knit 2 together) at the tail to thread the drawstring through.
• I-Cord: A technique to knit a sturdy, thin tube for the drawstring cord rather than just using a strand of yarn.
• Kitchener Stitch: Used if you choose to graft the nose shut seamlessly, though simple gathering works too.
• Embroidery on Knits: Using duplicate stitch or satin stitch to add eyes that won’t fall off in the tub.
• Picking up stitches: Required if you decide to knit the fins directly onto the body rather than sewing them on later.

Be very careful when embroidering the eyes; avoid using plastic safety eyes or buttons as they can become slippery hazards or detach when the soap shrinks the fabric.

Skill Level and Time Investment

One of the reasons I champion this craft is its high return on investment regarding time; you get a finished object very quickly. It is perfect for those weekends when you need a “win” after struggling with a larger, more complex project.

Here is a realistic breakdown of the learning curve.

Advantages and Challenges

No craft is perfect, and working with cotton to make 3D shapes presents its own unique set of pros and cons. I believe in being transparent about the process so you don’t get discouraged halfway through your first fish.

These points come from my own experience and discussions with my knitting circle.

The Joys of Making This:

• It is an incredible “scrap buster,” using up those 30-yard balls of yarn you can’t bear to throw away.
• The texture of knitted cotton provides excellent, gentle exfoliation that is better than plastic loofahs.
• They make fantastic, eco-friendly gifts that encourage children (and adults) to wash their hands.
• Cotton is durable, machine washable, and biodegradable, making this a zero-waste product.
• The project is small and portable, fitting easily into a purse for crafting on the go.
• You can easily customize the “species” of fish by changing colors to look like Nemo, a trout, or a shark.

The Realities to Consider:

• Cotton yarn has zero elasticity, which can be hard on your hands and wrists if you knit tightly.
• Shaping the mouth so the soap enters easily but doesn’t fall out requires precise tension control.
• If you use cheap cotton, the color might bleed in hot water, ruining the look of the fish.
• Knitting on double-pointed needles can feel like wrestling a hedgehog for beginners.

Real Project Applications

I once made a dozen of these for a summer craft fair, thinking they were just a silly novelty, but they sold out in the first hour. People love them because they solve the practical problem of “soap slime” in the soap dish while looking adorable. I have found they are particularly popular as baby shower gifts when paired with a high-quality organic oatmeal soap.

Another great application is for charity; I often knit these for children’s shelters. A simple bar of soap becomes a toy and a comfort object, making hygiene less of a chore for kids in difficult situations.

Are you tired of buying expensive spa gift sets?

A handmade fish scrubby, a nice bar of soap, and a small jar of bath salts make for a luxurious, personalized present.

For a truly polished look, knit the body in a self-striping cotton yarn; it does all the colorwork for you and makes the fish look like an exotic tropical species.

I also use them for camping trips because they hang dry from a tree branch or a shower hook. The “tail” acts as a natural hanger, keeping the soap off communal shower floors and allowing it to dry completely. It transforms a mundane necessity into a clever piece of travel gear.

The Learning Experience

When I first started teaching this pattern, I noticed that most students struggled with the transition from the body to the tail. It is easy to lose count of your stitches when decreasing rapidly, leading to a lopsided fish. I always tell my students: count your stitches at the end of every decrease round, or you will regret it later.

The secret to a durable soap sack is knitting at a slightly tighter gauge than the yarn label suggests. If your stitches are too loose, the fabric will stretch out when wet, and the soap will slip right through the mesh. My breakthrough came when I went down a needle size, creating a dense fabric that held its shape perfectly even when soaked.

There is nothing quite like the feeling of finishing the i-cord tail, threading it through, and seeing the flat piece of fabric suddenly transform into a recognizable fish.

YouTube is a fantastic resource for learning the specific techniques like the “Magic Loop” if double-pointed needles scare you. Don’t be afraid to rip back (frog) your work if the eyes look wonky; the small size makes fixing mistakes much less painful than on a sweater.

The community around these projects is huge, with many variations available for sharks, whales, and even platypuses.

Comparison with Similar Crafts

It helps to understand where this project fits in the wider world of fiber arts and soap making accessories. Here is how the knitted fish soap bag compares to other common methods of making soap savers.

Common Questions from Fellow Crafters

Q: Can I use wool or acrylic yarn instead of cotton?

A: Never use acrylic yarn for this project because it won’t absorb water and feels slimy against the skin. Wool is also problematic because the agitation and hot water in the bath will felt the wool, shrinking it down to a tiny, unusable size.

Q: How do I wash the fish soap bag?

A: You can throw it right in the washing machine and dryer with your towels. I recommend removing the leftover soap sliver first. The cotton actually gets softer and more absorbent the more you wash it.

Q: My fish looks long and skinny, what happened?

A: This usually happens if you knit too many rows for the body. Remember that cotton stretches when wet and heavy with soap, so it’s better to knit the body slightly shorter than your bar of soap—it will stretch to fit.

Q: Is this safe for babies?

A: Yes, provided you use embroidered eyes instead of plastic buttons. I also recommend using organic, un-dyed cotton yarn for newborns to ensure no dyes leech out, though high-quality commercial cotton is generally colorfast.

Q: How do I keep the drawstring from coming undone?

A: I like to tie a permanent knot at the very ends of the i-cord so the string can’t slip back inside the casing. When using it, a simple bow is usually enough to hold the soap in, as the wet friction helps secure the knot.

Q: Can I resize this for a giant bar of soap?

A: Absolutely. The pattern is based on math. Just increase your cast-on number by multiples of 4 (usually) to maintain the ribbing or pattern repeat, and knit the body section longer before starting the tail decreases.

My Personal Results and Insights

I keep a crafting journal, and looking back at my “Fish Era”, the data is actually quite surprising. It shows just how viable this is as a hobby that pays for itself or simply creates abundance for gifting.

Here is a snapshot of my production stats.

If you could create a gift that costs less than a cup of coffee but lasts for years, wouldn’t you want to make dozens of them?

Final Thoughts and My Recommendation

After knitting dozens of these aquatic scrubbies, I can honestly say that the fish soap bag is one of the most rewarding small projects you can master.

Lisa Mandel

It offers the perfect balance of technical engagement and mindless rhythm, making it an ideal project for movie nights or travel. While the lack of stretch in cotton yarn can be a minor annoyance, the utility of the final product far outweighs the stiffness during the process.

I highly recommend this project for knitters who are ready to move beyond flat scarves and dishcloths but aren’t quite ready for socks. It teaches you 3D shaping in a low-stakes environment where “perfect” isn’t strictly necessary—a lopsided fish is just a fish with character. However, make sure you weave in your ends securely, as the agitation of scrubbing can work loose ends free over time.

Do not underestimate the weight of a wet bar of soap; ensure your drawstring mechanism is robust, or you will have a sad, empty fish and a slippery bar of soap on your toe.

Give it a try with a bright ball of yellow cotton. Whether you are making it for a child who hates bath time or as a quirky gift for a friend, the joy of watching a flat piece of fabric puff up into a little fish never gets old. It is a humble craft, but one that brings a splash of fun to the most mundane part of our day.