For this blog, I wanted to spend some time examining and answering some very common questions I see asked having to do with shaving soap.
Does shaving soap go bad?
When you think of “bad soap”, you might be thinking of a mold-infested container or maybe something that’s turned a nasty color and smells funny. Let me explain some of what happens there. Mold is what naturally grows when there’s water present in a cosmetic. To combat this, nearly all cosmetic products contain a preservative that prevents the growth of microorganisms and allows the product to stay on a shelf more than a few days. Soap is kind of a different animal, though. Soap’s pH is generally too high for this type of growth to occur. So for that reason, it’s really rare to see mold in soap. That said, under certain conditions, anything is possible. But if a soap was well made, and you take reasonable steps to store it in common sense conditions, no, you’ll probably never see mold in one of your soaps.
Rancidity on the other hand, is a bit more common. Rancidity is what happens when the oils and fats in soap oxidize. This is most noticeable by an off-color of yellow or orange appearing and perhaps the soap starting to smell a little funny. This won’t hurt you and it generally won’t impact the performance of a soap either, though it can be a little off-putting. Rancidity in oils can be caused by an excessive superfat, the use of “easily spoilable” superfats, the use of aged raw materials, or the presence of something that oxidizes in the soap (like trace metals in hard water).
How are some soaps made to smell exactly like (popular fragrance)? Do soap makers re-create that scent themselves?
Short answer: probably not.
Long answer: there’s about 3 reasonable ways a shaving soap artisan would scent his or her soap. The first is that you buy pre-blended fragrance that’s ready-to-use and was made by someone else. This is how “clones” are generally made. You would buy fragrance from a company that specializes in fragrance oil creation and put that into your soap. (As a side note, it’s also possible to have a perfume analyzed – or GCMS tested – to determine its components, subsequently using that formula to blend a fragrance yourself. I assume some folks also do that to make clones.)
The second way is basically blending a bunch of blends. You might buy “bright citrus blend A” and combine it with “sandalwood accord B”. You are creating a new fragrance to some extent, but you are starting with pre-made selections, so to speak.
The final scent creation method is making it from scratch. You spend time trial-and-erroring tens or hundreds of blends of individual aroma chemicals and other smelly materials. This is just a crude form of perfumery. This is what I do with The Seven Collection soaps and it’s what some well-known artisans have become known for.
Though creating something from scratch is undoubtedly harder than buying something that’s ready to go, there’s no right or wrong way to go about it. It’s just an exercise in creative preferences, budget, and knowing your market.
Why is some soap soft and some soap hard?
There can be several contributing factors, but the biggest driver is likely the choice and/or proportions of lyes used. I use "lye" colloquially by the way. Technically, lye is sodium hydroxide, but for the purposes of this explanation, I'm using it to broadly refer to any strong base used to make soap. Sodium hydroxide and potassium hydroxide are the two (most common) lyes used to turn raw oils into soap. They have slightly different properties when it comes to things like water solubility, but they perform the same basic function in soap-making. However – for more complex reasons that are not necessary to explain here – they create different firmnesses in their salts (soap). In general, sodium hydroxide will make a hard bar of soap, and potassium hydroxide will make a soft (or liquid) soap.
Again, a lot of things can play a role (water content, superfat, additives), but if you put a super soft shaving soap next to a super hard, puck-like one, chances are the softer soap used a higher proportion of potassium hydroxide to sodium hydroxide than the other soap did.
Does scent fade in soap? Why?
Scent can definitely fade in soap. The smell of anything is just a molecule or a collection of molecules vaporizing. So if I’m smelling an essential oil, what’s happening is that those small, volatile scent molecules are evaporating and traveling into my nose. And since there’s not an unlimited amount of fragrance in soap, those molecules will eventually be all “used up”.
And as you’d probably expect, the older your soap is and the more exposed it is to air, the quicker the scent will fade.
The smell may also change a bit over time, as well. This again has to do with the rate of vaporization. All else equal, the smallest molecules will go away first, leaving the larger ones hanging around for longer. This is the concept of characterizing perfumes with top, heart, and base notes. A scent will evolve over the course of its wear time depending on the size and amount of the molecules in its note structure.
The same is true in soap. If you smell a soap that’s been left out in open air for years and compare it to the first day you purchased it, that soap will probably smell a bit different.
That said, employing the use of fragrance fixatives or anchors help to offset this effect to some extent, but physics is just hard to get around. In so many words, yes, scent can and will dissipate in soap. Keeping it in a container with a lid can extend the life greatly, just try not to lock a bunch of moisture in there (for quality reasons, not smell reasons).
Do exotic and unique ingredients make the soap better?
In my opinion, this is perhaps one of the greatest tragedies in the artisan shaving world. As small batch shaving soap has become so good, the ability for artisans to distinguish themselves in the market has become much harder. Some people have relied on packaging, excellent branding, or captivating fragrances to stand out. And more recently, I’ve seen a little bit of a trend in people boasting their use of this miracle oil or that amazing ingredient. While there’s lots of great stuff people put into shaving soap, I’m a big believer in the concept that a formulation makes a product great, not a single ingredient.
This rubs me the wrong way because it almost feels like doing this isn’t looking out for your customers. I’ve made hundreds – maybe thousands – of batches of soap with countless different ingredients. I have never, ever found an expensive ingredient that was the difference between making or breaking a formula. And in fact, in the case of oils used in soapmaking, most exotic oils have very similar fatty acid makeups to that of much cheaper alternatives.
There’s a somewhat deceptive practice in commercial cosmetic formulation, whereby ingredients are only used in very small quantities for exclusively the label callout: “made with jojoba oil!”. I’m afraid that this practice is slowly making its way to the artisan world of products.
Though I can’t speak for every single cosmetic product out there, my experience has been that the primary functional ingredients of most soaps absolutely do not need to be expensive to create a product with top shelf performance. Don’t feel like you need to pay a premium for that.
Why do some soaps leave your face dry and others don’t?
It’s easy to forget in the rituals of wet shaving that a shaving soap is actually just plain old soap. And soaps are made to clean stuff. Soaps are really good at grabbing onto oils and washing that stuff away. So a soap that has some particularly effective cleansing properties will strip your face of its natural oils, making your skin feel dry and raw.
The fact that soap cleanses skin is an unavoidable property of it. It’s soap, after all. But every soap is different. We, as shaving soap makers, try to minimize that impact as best we can by cleverly crafting the formula.
I don’t mean to paint with a broad brush, and this certainly isn’t always the case, but most of the time, you’ll find that commercially produced soap is generally more prone to drying out skin than the artisan stuff. Commercially produced soaps are typically made with more “basic” ingredients, little to no superfat, and few meaningful additives. That's because it needs to be easy to make in great quantities, quickly, and with very long shelf life considerations. Artisan shaving soap, and handmade soap in general, is just different in that way.
I picked up a shaving soap made at a local farmer’s market. It sucked. Why?
I’ve said it before, but a good shaving soap is a little bit specialized. Unless he or she does a good amount of research, even a talented bath soap maker will probably fail at making a good shaving soap.
It requires a lot of stearic acid, it requires “low cleansing oils” (for the reasons mentioned in the last question), it requires some extra glycerin, and it requires knowledge of the process; hot vs. cold process, temperature considerations, dual-lye usage, when to add things to the batch, and so on. These aren’t typical considerations in a bath soap or a hand soap.
It’s kind of like being proficient with a stick shift and then trying to drive an 18-speed semi-truck. If I’m a proficient stick shift driver, it’s probably possible – and even likely – that I have the potential to be a good truck driver. But until I learn and practice everything I need to know, like how to make wide turns and float gears, I’m probably not going to be any good at it.
I have a matching soap aftershave set, but they smell kind of different. Why is that?
This is another oddity that has more to do with perfumery than soap-making. We’ve established that fragrances are just a bunch of molecules of varying sizes, and that the molecules evaporate in descending order of “largeness”. So the first thing that can impact the fragrance in a soap is the heat. While we’re making it, we have to add fragrance to shaving soap at well over 100 degrees. Most of the time it’s probably going to be between 120 and 180. “Exciting” the molecules by heating them up can make them evaporate quicker. So the fact that heat is present in soap when the fragrance is added is one reason the soap’s fragrance may deviate from the original scent.
Another reason is that other soap ingredients themselves have a muddying impact with respect to smell. Tallow smells a little animalic and milky. Stearic acid is a bit like wax and plastic. Lanolin smells like wet fur. All this stuff combined in a pot can certainly interact with fragrance in an undesired way.
The last reason is a little more scientific. There are actually molecules in fragrances that can react with lye, much like oils in saponification. For example, linalyl acetate – which is found in stuff like lavender essential oil – can react with lye and create linalool. I use this example often because it’s a good one. If you were to make a lavender essential oil soap and added it before all the lye was reacted, you may wonder why the finished bar smells a little more like lemon than the original fragrance. That would be why!
One or all these things can play a role in a way that isn’t normally a consideration in aftershave creation.
That's all for today, folks. If you have a topic you'd like me to cover in one of these blogs, feel free to shoot me an email and suggest it (email@example.com).
Until next time!