Oatmeal, Honey and Goat Milk Soap: Cold Process Recipe and Method

An oatmeal, honey and goat milk soap is a soft, creamy, gentle bar loved for sensitive skin, made by soaping with milk instead of water and adding soothing oats and honey. It is also a cosmetic product, so the moment you sell it in Great Britain it must comply with the UK Cosmetic Products Enforcement Regulations 2013 and the retained Regulation (EC) No 1223/2009, overseen by the Office for Product Safety and Standards. This guide gives you the full formulation, the method, and a clear path to selling it legally.

This recipe is part of our maker series. If you want a wider library of tested formulas across skincare, hair care and more, our 100 Beauty Formulas cosmetic formulation guide collects one hundred professional formulations in one place.

Why goat milk, honey and oatmeal?

This trio is a classic for a reason. Goat milk gives a rich, creamy lather and a soft, cushioned feel, and its natural fats add to the conditioning quality of the bar. Honey is a humectant, which means it draws moisture towards the skin, and it also gives a small lather boost and a warm colour. Colloidal oatmeal, which is simply oats milled to a fine powder, is one of the most trusted skin soothers there is.

Put together, they make a bar that is gentle, comforting and well suited to sensitive, dry or easily irritated skin. It is the kind of soap customers buy again and again, and it makes a lovely gift, so it earns its place in any handmade range.

• Soothing. Colloidal oatmeal and goat milk calm and comfort the skin.
• Moisturising. Honey draws in moisture and the milk fats condition.
• Creamy lather. Goat milk gives a soft, lotion like foam.

What is saponification?

Saponification is the chemical reaction at the heart of every real soap. When oils and butters, which are triglycerides, are mixed with sodium hydroxide dissolved in water, the two react to form soap and glycerin. The important safety point is that the sodium hydroxide is used up in the reaction. A correctly made, fully cured bar contains no free lye, which is exactly why finished soap is safe and gentle to use on the skin. Understanding this also explains why measuring matters so much: too little lye leaves a soft, oily bar, while too much leaves a harsh, lye heavy one.

A safety word before you start

Cold process soap is made with sodium hydroxide, also known as lye or caustic soda. It is a corrosive alkali that can cause serious chemical burns and permanent eye damage before it is saponified, so it deserves real respect. Treat it as a hazardous substance and follow the Health and Safety Executive guidance on the control of substances hazardous to health (COSHH), along with the safety data sheet supplied with your lye. The essential rules are simple and non negotiable:

• Wear personal protective equipment. Safety goggles, chemical resistant gloves and long sleeves at all times when handling lye or raw soap.
• Work in a well ventilated space, away from children and pets, with windows open or extraction running.
• Always add lye to water, never water to lye. Adding water to lye can erupt violently. Makers remember it as snow floats on water, so you sprinkle the lye onto the water.
• Keep white vinegar nearby to neutralise surface spills, and rinse any skin contact with plenty of cool running water.
• Use dedicated soaping equipment that never touches food again, and label it clearly.

This level of care is only needed at the raw lye stage. Once your soap has saponified and cured, it is simply soap, mild and safe to use.

Milk soaping adds one extra safety point on top of the usual rules: because you are adding lye to frozen milk rather than water, keep the container in an ice bath and add the lye very slowly, so the milk stays cold and does not scorch or release unpleasant fumes.

Equipment you will need

• A digital scale accurate to one gram, for weighing every ingredient
• A stick blender (immersion blender) to reach trace quickly
• Two heatproof jugs, one for the lye solution and one for the oils
• A stainless steel or heavy plastic mixing bowl, never aluminium, which reacts dangerously with lye
• A silicone spatula and a digital thermometer
• A silicone loaf mould or individual cavity moulds
• Safety goggles, chemical resistant gloves and an apron

Avoid aluminium and non stick coatings entirely, as lye corrodes aluminium and can release hydrogen gas. Stainless steel, silicone and heavy duty plastic are the safe choices, and keeping a dedicated set of soaping tools makes every batch cleaner and safer.

The oatmeal, honey and goat milk formulation

This makes roughly 1.3 kilograms of soap, by weight. The goat milk is used frozen, in place of the water, and the honey and oatmeal are stirred in at trace.

Verify before you make it. Run your exact recipe through a reputable lye calculator before mixing, and set a six percent superfat when you do.

Freeze the milk. Goat milk scorches and turns orange or brown if it gets too hot with the lye. Freeze it to a slush first and add the sodium hydroxide a little at a time, keeping the container in an ice bath and stirring constantly.

Mind the honey and sugars. Honey and the natural sugars in milk both generate heat as the soap saponifies, so soap at a low temperature and do not insulate the mould, or the batch can overheat, crack or even bubble up.

Colour is normal. Milk and honey soaps naturally cure to a warm cream or tan colour. This is expected and part of their charm.

How to make it, step by step

Allow about ninety minutes of active work, plus freezing the milk in advance, then a couple of days before unmoulding.

1. Prepare

Wear goggles and gloves, keep children and pets away, weigh everything, and freeze the goat milk into cubes or a slush beforehand.

2. Milk and lye

Set the frozen goat milk in an ice bath and add the sodium hydroxide a spoonful at a time, stirring well between additions so the temperature stays low. The milk will thicken and turn pale yellow, which is completely normal.

3. Prepare the oils

Melt the coconut oil and shea butter, then add the olive, sunflower and castor oils. Stir the colloidal oatmeal through the oils, and gently warm the honey with a teaspoon of water so it blends in smoothly later.

4. Combine and blend to trace

With both the milk lye and the oils around thirty to thirty five degrees Celsius, pour the lye into the oils, add the honey, and blend gently to a light trace. Milk and honey batters move quickly and can heat up, so do not over blend.

5. Mould and keep cool

Pour into the mould and leave it uncovered in a cool place, or even in the fridge or freezer for the first few hours, to stop it overheating. Do not wrap or insulate it.

6. Unmould and cut

Unmould after two to three days, as milk soaps stay soft at first, and cut into bars while wearing gloves.

Curing your soap

Cure the bars for four to six weeks in a cool, dry, airy place, turning them occasionally. The bar mildens and hardens as it cures, and the creamy colour deepens a little.

Testing your soap

Two simple checks confirm your bar is safe and ready to use.

• The zap test. Touch a well cured bar briefly to the tip of your tongue. Soap tastes of soap. A sharp, battery like zap means there is unreacted lye, so the bar needs a longer cure or has a recipe error. Only zap test a bar that has cured for several weeks.
• pH. Handmade soap is naturally alkaline, usually around pH nine to ten, which is completely normal for a soap. Check with pH strips on a wet lather. A reading well above this range suggests a lye heavy batch, so recheck your measurements before selling it.

Storing and using your soap

Once cured, keep your bars somewhere cool, dry and out of direct sunlight, ideally loosely wrapped or boxed so they stay clean and firm rather than gathering dust or softening. In the shower or by the sink, a well drained soap dish that lets the bar dry fully between uses will make it last far longer, because a bar left sitting in a puddle of water softens and dissolves quickly.

Handmade soap is at its best within about a year of its cure date, although a well made, well stored bar will happily keep for longer than that. If you sell your soap, remember that its shelf life, storage conditions and the period after opening all form part of the information a safety assessment reviews, so it is worth keeping a clear note of every batch date from the start.

Labelling your soap for sale

Selling your soap means labelling it correctly, and the requirements are specific. Under Regulation (EC) No 1223/2009 and the UK cosmetic rules, a cosmetic label must carry the name and function of the product, the name and address of the Responsible Person, the country of origin where required, the nominal weight at the time of packaging, a batch number, the period after opening or a minimum durability date, any mandatory warnings, and a full ingredient list. That list must use INCI names in descending order of weight, and for a cold process soap the oils appear in their saponified form, so olive oil is listed as Sodium Olivate, coconut oil as Sodium Cocoate, shea butter as Sodium Shea Butterate, and so on, alongside water (Aqua), the naturally produced glycerin, and any fragrance allergens that sit above their declaration thresholds.

The ingredient list, the allergen declarations and the mandatory warnings are the three places small brands most often slip up, so it is well worth having a label and packaging review before you commit to a print run. A correct, professional label keeps you compliant, saves you from costly reprints, and builds real trust with the customers who take the time to read it.

Troubleshooting common problems

• Orange or brown patches. The milk overheated with the lye. Keep it colder and add the lye more slowly next time.
• A crack down the middle. The soap overheated in the mould. Soap cooler and never insulate a milk and honey soap.
• A strong ammonia smell. A sign the milk scorched. Keep everything cold during the lye stage.
• Soft bar. Normal early on for a milk soap. Give it a longer cure and it will firm up.

Variations

• Lavender and oat. Add lavender essential oil for a calming bedtime bar.
• Honey oatmeal scrub. Leave the oats a little coarser for a gently exfoliating bar.
• Vegan version. Replace the goat milk with oat or coconut milk and the honey with a little vegetable glycerin for a gentle, plant based bar.

From kitchen to shelf: selling your soap legally

Handmade soap is a cosmetic, so the moment you sell it, it must meet UK and EU cosmetic law before it goes on the market. Here is what compliance involves.

• A Cosmetic Product Safety Report. Every cosmetic sold in the UK or EU needs a Cosmetic Product Safety Report (CPSR), a formal safety assessment signed by a qualified Safety Assessor under Regulation (EC) No 1223/2009. If you make several variants, they can be assessed together as a range through our multiple variant CPSR service.

• The full document set. Alongside the CPSR you must hold a Product Information File, and your product must be notified. Our all in one compliance package covers the CPSR, PIF, SDS and notification together.

• Notification. Before sale, your product is notified in Great Britain through the Submit cosmetic product notifications service (SCPN), and in the EU through the CPNP, which we handle in our CPNP product notification service. It is declared under the correct frame formulation, a toilet soap, so your exact recipe stays private.

• Responsible Person and labelling. Every product needs a Responsible Person who is legally accountable to the authorities, and a compliant label. Phoenix can act as your UK and EU Responsible Person and carry out a label and packaging review.

• Selling in the United States? Under the Modernization of Cosmetics Regulation Act, the US Food and Drug Administration now requires facility registration and product listing for many cosmetics, which we manage through our FDA MoCRA listing service.

When you are ready to take your soap to market, contact Phoenix Safety Consultants and we will guide you through every step.

Frequently asked questions

Why does goat milk soap turn orange?

The natural sugars in the milk caramelise if the lye gets too hot. Freezing the milk and adding the lye slowly keeps the colour pale and creamy.

Is oatmeal honey goat milk soap good for sensitive skin?

Yes. Goat milk, honey and colloidal oatmeal are all gentle, soothing ingredients, which is why this bar is so popular for sensitive and dry skin.

Can I make this soap vegan?

Yes. Replace the goat milk with oat or coconut milk and the honey with a little vegetable glycerin. It will no longer be a goat milk soap, but it will still be gentle and soothing.

Why should I not insulate this soap?

Honey and milk sugars generate heat during saponification, so insulating can cause the soap to overheat and crack. Keep it cool instead.

Do I need a CPSR to sell milk soap?

Yes. Any cosmetic sold in the UK or EU, including milk soap, needs a Cosmetic Product Safety Report, a Product Information File, a Responsible Person and a compliant label.

Related reading

• CPSR for Whipped Soap (UK and EU guide)
• CPSR for Lip Scrub (UK and EU guide)
• CPSR for Body Mist (UK and EU guide)

About the author

This article is educational. Always run your recipe through a lye calculator, follow proper safety practices, and have any product professionally assessed before selling it.