Glycerin in Handmade Soap: Why It Stays, Why It Matters

What Exactly Is Glycerin – And Why Does Skin Love It?

Glycerin (or glycerol) is a clear, syrupy liquid that appears naturally when oils and butters are turned into soap. In skincare, it's known as a humectant, which means it attracts and holds onto water.

A scientific review on skin hydration mechanisms explains that humectants like glycerin help the outer layer of the skin (the stratum corneum) stay flexible and better hydrated. Another dermatology paper, " Glycerol and the skin: holistic approach to its origin and functions ", highlights how glycerin improves hydration, barrier function and even the mechanical properties of the skin.

In simpler terms, glycerin helps your skin:

• Draw water into the outer layers

• Hold onto that water for longer

• Stay softer and less prone to cracking or flaking

You'll see the same message repeated in expert-led articles, from Healthline's overview of glycerin for the face to E45's guide to glycerin in skincare and even dermatologists interviewed in Vogue's feature on glycerin as a "super hydrator".

For me as a soap maker, glycerin is a natural ally. It's created inside the bar itself and works quietly every time you wash.

Why Handmade Soap Keeps Its Natural Glycerin

When I make soap using the cold process method, I blend plant oils or butters with a lye solution. As the mixture saponifies, two key things are created:

1. Soap

2. Glycerin

In a traditional, small-batch setting, that glycerin simply stays in the bar. It's part of why a well-formulated handmade soap feels so different on the skin.

If you'd like to see how we work, our post on cold process soap making and why we honour traditional methods explains how this slower process protects the natural properties of oils and keeps their glycerin intact.

By contrast, many mass-produced "soaps" are either:

• True soaps that have had much of the glycerin removed and sold on for use in lotions and creams, or

• Synthetic detergent bars (sometimes called "beauty bars") designed primarily for foaming and long shelf life, not skin comfort.

That's one reason some commercial cleansers leave you feeling tight and itchy. You're getting the cleansing power, but not necessarily the humectant comfort your skin is quietly asking for.

What Research Really Says About Glycerin and Skin

Glycerin isn't just popular because it feels nice; it's one of the most studied ingredients in dermatology.

• The review on skin hydration describes glycerin as a key humectant in the stratum corneum, helping skin hold onto water and stay flexible.

• The holistic review of glycerol and the skin notes that glycerin improves hydration, strengthens barrier function and can even support wound healing.

• Clinical research has shown that glycerin-containing formulations can support healthier barrier repair over time.

When you look at practical guidance, dermatology organisations say much the same. The NHS overview of emollients explains how moisturisers help trap water in the skin to manage dry, itchy conditions like eczema and psoriasis. The British Association of Dermatologists' leaflet on emollient use reinforces how important it is to protect the skin barrier with hydrating ingredients used frequently and generously.

In other words, glycerin fits perfectly into what dermatologists already recommend: cleansers and moisturisers that support hydration and barrier function, rather than stripping everything away.

Glycerin Natural Soap Benefits You'll Notice Day to Day

So what does all this science actually feel like on your skin? In my experience – and from customers who've switched to glycerin-rich handmade bars – people tend to notice a few specific changes.

1. Less Tightness After Washing

That "squeaky clean" feeling is often a sign that your cleanser has removed more than just surface grime. If your skin feels tight, shiny or itchy after washing, your barrier might be taking a hit.

With a gentle handmade bar that keeps its natural glycerin, you're more likely to feel clean but comfortable. Your skin doesn't need to "recover" for an hour before it feels like itself again.

If you like to dig into ingredient lists, our guide to moisturising bar soap and the top 9 ingredients to look for explains how glycerin sits alongside butters, oils and botanicals to create a bar that cleanses without stripping.

2. Softer, More Supple Skin Over Time

Glycerin helps the outer layer of your skin hold onto water more effectively. When you pair a glycerin-rich soap with a good emollient afterwards, many people find their skin becomes softer and more supple over a few weeks.

Articles like Healthline's overview of vegetable glycerin and E45's explanation of glycerin's role in moisturisers echo this, highlighting improved hydration, smoother texture and support for irritated or damaged skin.

3. Better Tolerance if You're Dry or Sensitive

If you live with dry, sensitive or eczema-prone skin, you probably already know the advice: avoid harsh soaps and use gentle cleansers plus plenty of emollients. The NHS guidance on emollients and documents like the North East London emollient prescribing guidelines both stress how important it is not to undo the work of your moisturiser at the sink.

A handmade bar with retained glycerin and gentle oils won't cure a skin condition, but it can be a much kinder step in your routine than a harsh, foaming wash. If this is a concern for you, our in-depth piece on discovering the best soap bars for sensitive skin shares how I think about formulating for delicate, reactive skin.

Does Every Handmade Soap Contain Glycerin?

If it's made through true saponification (cold process or hot process), then yes: glycerin is always created as part of the reaction between oils and lye.

The real difference is what happens next:

• In small-batch handmade soap, the glycerin usually stays put.

• In many industrial settings, glycerin is separated out and sold to go into other skincare products.

Some translucent "glycerin soaps" are made from melt-and-pour bases that have had extra glycerin added, which can make them more prone to attracting moisture from the air and getting "sweaty" in humid bathrooms. That doesn't mean glycerin itself is a problem – it's just doing what humectants do best.

If you'd like to see how we balance all this in practice, our post on coconut oil soap and its natural cleansing and lather benefits talks about how we use the cold process method to keep glycerin in the bar while still achieving that satisfying, bubbly lather.

How We Formulate with Glycerin at The Humble Shepherd

At The Humble Shepherd, we don't see glycerin as an "add-on". It's part of the natural story of a well-made bar.

Here's what that looks like behind the scenes:

• Cold process as standard – We use traditional cold process techniques so the natural glycerin created during saponification stays in the bar alongside the oils and butters. You can read more about this in our deep dive into cold process soap making.

• Balanced superfat levels – We calculate a gentle superfat – the small amount of unsaponified oil left in the finished bar – so there's extra richness without leaving the skin coated or greasy.

• Thoughtful ingredient choices – We pair glycerin with skin-loving oils such as shea, olive and other emollients. If you like to know what's inside your bar, our guide to moisturising bar soap ingredients walks through the key players one by one.

We also think about the bigger picture. Switching to solid bars is one of the simplest ways to cut down on plastic in the bathroom. Our post " Zero Waste Bathroom: How Switching to Bar Soap Reduces Plastic by 70% " explores how bar soap fits into a more sustainable routine, supported by research such as this life cycle assessment of bar soap production.

Building a Simple, Glycerin-Friendly Routine

Glycerin works best as part of a joined-up routine rather than a lone hero ingredient. Here's a straightforward way to put it all together.

1. Use a Gentle, Glycerin-Rich Cleanser

Choose a handmade bar that retains its natural glycerin and uses mild oils. Use lukewarm water rather than very hot, and let the lather do the work instead of scrubbing hard.

If you're simplifying your bathroom shelf, our guide to building a simple daily skincare routine with natural products offers a step-by-step way to pair your soap with just a few well-chosen extras.

2. Pat Dry, Don't Rub

After rinsing, gently pat your skin with a soft towel so it's still just slightly damp. That's the perfect base for your moisturiser.

3. Apply an Emollient Within a Few Minutes

NHS and dermatology guidance is very consistent on this: if you have dry or sensitive skin, it helps to apply emollients soon after washing to trap in the water. The NHS emollient page, alongside documents like the North East London emollient prescribing guidance, emphasise frequent, generous use.

The British Association of Dermatologists' advice on hand care is also helpful, especially if your hands take a lot of wear and tear.

4. Turn It into a Small Ritual

Skin care doesn't need to be elaborate to feel nourishing. Many people find that making a small ritual of their evening wash can be just as helpful for the mind as it is for the skin.

If that appeals, you might like our piece on creating your own spa experience at home with natural products, which shows how a simple bar of soap can sit at the heart of a calming, spa-like routine.

When Soap Isn't Enough

Even the best-formulated soap has its limits. If you are dealing with:

• Persistent, inflamed rashes

• Cracked, bleeding skin

• Rapidly worsening eczema, psoriasis or another diagnosed condition

then a gentle, glycerin-rich bar is simply a supportive step, not a treatment. Dermatology bodies like the British Association of Dermatologists and NHS resources on emollients and eczema make it clear that emollients, prescription treatments and medical guidance all have a role to play.

I always recommend patch testing new products and speaking to your GP or dermatologist if you're unsure. Handmade soap can be a kind companion for your skin, but it should never replace professional care where it's needed.

A Small, Gentle Next Step

If this has helped you understand glycerin a little better, the next step doesn't need to be complicated.

You can:

• Explore our bars and add your name to product updates on the Shop Now and waiting list page so you're notified when fresh small batches leave the curing racks.

• Learn more about our ethos on the About Us page, where we share why we believe soap can uplift lives as well as cleanse skin.

• Wander through the blog home to explore more guides on ingredients, routines and eco-conscious living.

If you'd like to be first in line for new releases, you're very welcome to sign up to our waiting list. That way, you'll get a gentle email when new, glycerin-rich bars are ready – never spam, just a quiet nudge when something lovely comes out of the mould.

Frequently Asked Questions

1. Is glycerin soap good for very dry skin?

Yes, as long as the bar is formulated gently. Glycerin helps your skin hold onto water and is widely used in products for dry and sensitive skin. Dermatology guidance on emollient use still recommends pairing a mild cleanser with regular moisturiser or emollient application for the best results.

2. Can I use glycerin-rich handmade soap on my face?

Many people do, especially if they prefer a simple routine. Choose an unscented or lightly scented bar designed for sensitive skin, introduce it slowly, and watch how your skin responds. If you have active acne, rosacea or another diagnosed condition, it's always wise to check with your GP or dermatologist first.

3. Does glycerin soap replace moisturiser?

No. Glycerin makes the cleansing step more comfortable and helps your skin hold onto water, but it does not replace a leave-on moisturiser. Applying an emollient or lotion within a few minutes of washing, as recommended in emollient prescribing guidance, locks that hydration in.

4. Is glycerin comedogenic – will it clog my pores?

Glycerin is generally considered non-comedogenic and is widely used in formulas for all skin types, including oily and combination skin. Articles such as E45's guide to glycerin note that it supports hydration and barrier health without necessarily clogging pores, though the overall formula and your skin type still matter.