How is bar soap made? How is extruded soap different than poured soap? And for brands developing bar soap, what are your aesthetic and packaging options?
Twincraft Skincare has manufactured bar soap at our Winooski, Vermont factory since the early 1970s. The popularity of bar soap with different consumer groups has evolved over time, but we've always been here as an innovator for this industry and as a true partner for brands that want to add solid cleansers to their own product offering.
Here, we present a basic overview of how bar soap is made in our extrusion facility, what these bars can look like, and the basic packaging offerings that we provide for our many customers.
Extruded Bar Soap vs. Poured Bar Soap
Many small-scale soap makers and at-home crafters are familiar with the process of making soap by pouring liquid soap into a mold and letting it set and harden before use. Poured soap allows for unique visual aesthetics to be achieved, but this process is very labor intensive and difficult to scale up.
Our process for finishing and extruding bar soap is highly efficient and produces consistent bars that last much longer than a poured version. Many years ago, Twincraft manufactured poured bar soap for a select group of customers, but this was not a scalable or efficient way to make bar soap, so we focused our efforts on offering extruded bar soap options that to provide the best possible quality products to our customers, and to consumers.
What Is Soap Finishing?
Twincraft Skincare is a soap finisher, which means that we do not manufacture soap base in-house. Instead, we partner with the world's top suppliers to use a pre-saponified base in the form of soap pellets, which become the foundation of our finished goods.
How Is Extruded Bar Soap Made?
Bar soap finishing can be broken down into four primary stages:
Each bar soap that we finish starts at the batching stage. A Batch Maker is responsible for mixing ingredients according to our lab’s formulation specs. Soap pellets are weighed according to a batch sheet and dispensed into a large mixer. Any dyes or titanium dioxide is also added to the batch, and color is tested against an agreed upon standard before adding remaining ingredients.
Refining and Extrusion Stage
Our bar soaps pass through a process that qualifies them as triple milled or French milled, depending on the marketing claims a brand would like to use. The first refiner extrudes the soap base through a mesh screen to break the batch down into soap ribbons and the second refiner pushes the ribbons through another mesh screen. The soap passes through a vacuum chamber, which pulls air out of the soap to ensure that it is free of air pockets or streaks. In the final extrusion stage, a nose cone heats the outside of the soap slug to make it more pliable and perfect for pressing. An extrusion plate dictates the slug’s shape as it is prepared for the next stage.
Soap slugs are cut into a shape that will fit the selected die using a Uni-Cutter. Cut slugs are moved along on a conveyor belt as they prepare for the pressing stage.
Bar soaps that are made here at Twincraft are pressed in one of two options: a condor press or an STU press.
A condor press compresses two portions of the shape together, resulting in excess soap being squeezed out through a parting line around the perimeter of the bar. All condor pressed bars have parting lines, but they can be a high- or mid-parting line, depending on the die used and the desired final result. Condor presses are highly efficient as excess soap is recycled into the soap extruder and is easily reused to make more bars.
A STU press utilizes a soap slug that is cut to just under the length of the desired shape, and pressed in a ring to the weight of the finished soap. STU pressing results in very little excess soap, and will always have a solid band around the perimeter of the bar where it was formed in the ring.
Bar Soap Packaging
Our bar soap customers have two packaging options for their products: in-line packaging or staged wrapping. Package selection is a very important part of the bar soap development process, as different options can help tell a sustainability story, or help stop soap sweating from occurring.
In-line packaging occurs immediately after bars are pressed; finished bars are placed on the line and packaged by machines in their respective wrap, including cartons, paper wrap, flow wrap, or in a bulk pack.
Stage wrapped bars are moved from our pressing room to our wrapping room where they are placed in a crease wrap, sollas wrap, paper wrap, tissue wrap, or shrink wrap.
Bar Soap Aesthetics
While we extrude 100% of the bar soap that ships out from our facility, we are able to manufacture products that feel unique, featuring aesthetics that replicate hand-poured techniques and artisanal qualities.
We are inspired by poured soap trends, especially as they relate to popular natural ingredients, and our innovation team is always working to develop new manufacturing techniques to replicate the hand-crafted look and feel that attracts premium bar soap consumers.
We are able to achieve a hand-cut look that mimics the shape and feel of handmade varieties, and have the capabilities to imprint bars with randomized logos, textures, and indentations. We are also able to combine soap noodles with the base to give a swirled effect that we refer to as a "galaxy bar," which can also be interpreted as a tie dye aesthetic.
Through coextrusion techniques, we are able to achieve a layered look, combining multiple bases with different skincare benefits into one unique bar concept. We showcased this technology in our luxe bars, which replicated the layered look of geodes and minerals like quartz with sustainable glitter additives.
To learn more about our manufacturing capabilities, please contact our Sales team.