The Importance of Temperature in Cosmetic Formulation

When it comes to creating high-quality cosmetics, one of the most critical yet often overlooked aspects is temperature control. Whether you're formulating a simple lotion, a luxurious cream, or an advanced serum, maintaining the correct temperature throughout the formulation process is key to achieving the desired product stability, texture, and efficacy. Let’s explore why temperature is so important in cosmetic formulation, how ingredients react to different temperatures, and the consequences of incorrect temperature management.

1. Understanding Heat Sensitivity of Cosmetic Ingredients

Cosmetic ingredients vary widely in their chemical compositions and physical properties. Many active ingredients, emulsifiers, and thickeners are heat-sensitive, meaning their beneficial components can be destroyed or significantly reduced when exposed to incorrect temperatures.

Common Heat-Sensitive Ingredients:

• Vitamins & Antioxidants: Ingredients like Vitamin C (Ascorbic Acid), Vitamin E

  (Tocopherol), and Retinol (Vitamin A) are all susceptible to degradation when exposed to heat. Vitamin C, for instance, is known for its instability and can easily oxidize or break

  down when exposed to temperatures above 40°C (104°F), making it less effective in the

  final product.

• Proteins & Extracts: Hydrolyzed proteins and botanical extracts, such as Green Tea,

  Chamomile, and Aloe Vera, can lose their beneficial properties when overheated. Many

  natural extracts contain active compounds that are highly sensitive to heat and may lose

  their antioxidant, anti-inflammatory, or soothing benefits if processed improperly.

• Preservatives: Preservatives like OptiphenTM and Liquid GermallTM Plus can degrade at

  high temperatures. This not only reduces the efficacy of the preservative system but also

  compromises the overall safety of the formulation.

• Other Heat Sensitive Materials

The Bottom Line: If you add these ingredients at the wrong temperature, you risk

compromising their benefits or rendering them ineffective altogether.

2. Phase Temperatures and Emulsion Stability

When formulating emulsions, which are mixtures of water and oil phases, temperature plays a pivotal role in forming stable, homogeneous products. Emulsifiers, thickeners, and waxes often need to be processed at specific temperatures to facilitate proper mixing and emulsion formation. Without maintaining the correct temperature, your product is more likely to separate, curdle, or become unstable over time.

Why Phase Temperatures Matter:

• Hot Processing of Emulsifiers and Waxes: Many emulsifiers require heating to melt

  into the oil phase properly. Emulsifying Wax NF and Polawax, for instance, are solid at

  room temperature and need to be heated to around 70-80c to melt and fully incorporate into the oil phase. Without reaching this temperature, the emulsifier will not mix well, leading to separation and an unstable emulsion.

• Temperature Matching of Phases: When creating oil-in-water (O/W) or water-in-oil

  (W/O) emulsions, both the oil phase and water phase must be heated to the same

  temperatures before mixing. This temperature matching ensures that the emulsifier

  works effectively to bind the two phases together. If one phase is too cold or too hot, the emulsifier may not be able to create a stable bond, resulting in an unstable or even

  unusable product.

General Temperature Guidelines for Emulsions:

1. Heat Both Phases Separately: Heat the oil phase (containing oils, butters, emulsifiers,

   and oil-soluble thickeners) and water phase (containing water, humectants, and

   water-soluble thickeners) separately to around 70-80c. This is crucial to ensure all raw

   materials are properly melted or dissolved.

2. Combine at the Same Temperature: Once both phases reach the correct temperature,

   combine them with high-shear mixing to create a stable emulsion. Emulsions created

   below this temperature threshold often fail to emulsify properly, leading to an unstable

   product that separates or forms lumps over time.

Cold vs. Hot Processing: Some formulations, such as cold-process emulsions, do not require

heating. However, it is essential to recognize that these formulations often use specialized

emulsifiers and thickeners that can create stable emulsions at room temperature.

Understanding the specific needs of your formulation and ingredients is crucial to deciding

whether hot or cold processing is necessary.

4. Preservation and Stability Testing

The preservation system is vital for preventing microbial contamination in water-based

cosmetics. However, many preservatives are sensitive to temperature and pH changes.

Overheating a preservative can compromise its efficacy, resulting in a product that is prone to spoilage.

Recommended Tips for Adding Preservatives:

• Cool Down Before Adding Preservatives: Most preservatives should be added to the

  formulation once the mixture has cooled to around 40°C (104°F) or lower. This prevents

  any potential heat damage and ensures the preservative retains its full efficacy.

• Mix Gently: Once the preservative is added, mix gently to prevent incorporating too

  much air or affecting the viscosity of the final product.

5. Summary: The Key Points to Remember

1. Understand the Heat Sensitivity of Your Ingredients: Know the melting points,

   degradation temperatures, and stability profiles of the raw materials you're working with.

2. Control Phase Temperatures in Emulsion Formulation: Ensure both oil and water

   phases are heated to the proper temperatures and combined correctly for stable

   emulsions.

3. Optimize Viscosity and Texture Through Temperature Management: Properly heat

   thickeners, gelling agents, butters, and waxes to achieve the correct viscosity and feel.

4. Add Heat-Sensitive Ingredients & Preservatives at the Correct Stage: To maintain

   their benefits and ensure effective preservation, add heat-sensitive ingredients only

   when the formulation is at the appropriate temperature.

By understanding and controlling temperatures throughout the formulation process, you can

achieve stable, effective, and high-quality cosmetic products with consistent performance.

Temperature control is not just about melting ingredients or mixing phases—it's about optimizing the stability, efficacy, and sensory experience of your final product. So, always check the temperature requirements for each ingredient and phase of your formulation to ensure your products are as effective and luxurious as intended.

The Importance of Working with Accurate Thermometers

A critical aspect of maintaining the correct temperature during cosmetic formulation is using an accurate thermometer. It might sound simple, but temperature control is only as effective as your measurement tools. Using an inaccurate or inconsistent thermometer can lead to

misreading temperatures, resulting in improperly processed ingredients and ultimately

compromising the quality and stability of your formulations.

1. Accurate Measurements for Sensitive Ingredients

   
   

   Many ingredients in cosmetics are sensitive to even slight variations in temperature. For

   instance, an antioxidant like Vitamin C may degrade quickly if exposed to temperatures slightly above 40°C (104°F). If your thermometer isn't accurate or calibrated correctly, you could mistakenly overheat your formulation, breaking down the active ingredient before it even reaches the final product.

   
   

   Similarly, waxes and emulsifiers have melting points that must be reached for proper

   incorporation. A difference of even a few degrees can make the difference between a properly formed emulsion and one that separates or remains gritty. Using an accurate thermometer ensures that you’re working within the right temperature ranges and preserving the integrity of your ingredients.

   
   

2. Ensuring Emulsion Stability and Consistency

   
   

   Accurate thermometers are especially crucial when formulating emulsions. You must heat both the oil phase and water phase to specific temperatures, typically between 70-80c, to achieve proper mixing and bonding of the phases. If your thermometer provides inaccurate readings, you might think the oil and water phases are ready to combine when they are not. This can lead to a poorly formed emulsion, affecting product stability and consistency.

   
   

   For emulsions, a digital thermometer or an infrared thermometer with precise readings is recommended. These tools can help ensure you're reaching and maintaining the correct temperatures without waiting too long or combining phases prematurely.

   
   

3. Monitoring Cooling for Sensitive Additives and Preservatives

   
   

   After combining the phases, the cooling process is equally important. Many sensitive additives and preservatives need to be added at specific lower temperatures, usually around 40°C (104°F) or below. If your thermometer is off by just a few degrees, you risk adding these components at too high a temperature, potentially degrading their effectiveness or altering the product's pH balance.

   
   

   Incorporating an accurate thermometer during the cooling phase helps ensure you’re adding these ingredients at the proper stage to maximize their benefits and achieve a stable, safe product.

Accurate thermometers allow you to monitor these critical points effectively. For

example:

• Digital Thermometers: These offer quick and precise readings, making them perfect for

  tracking the temperature of both oil and water phases in real-time. They're easy to use,

  have quick response times, and display temperatures with precision, often to one

  decimal place.

• Glass Lab Thermometers: These classic thermometers are highly accurate and can

  withstand high temperatures. They are an excellent choice for measuring the

  temperatures of phases during hot processing. However, care must be taken to avoid

  breaking the glass, which could lead to contamination.

• Candy Thermometers: Surprisingly versatile, candy thermometers are great for

  high-heat applications. Their large, easy-to-read scale makes them particularly useful for

  monitoring phases that require precise temperature control, like melting waxes or

  butters.

Common Natural Skincare Mistakes: What BeginnersNeed to Know

When starting to make your own skincare products, it’s easy to get caught up in the

desire to use natural and safe ingredients. If I had to estimate, I’d say that upwards of

99% of people—myself included—begin this journey because they’ve lost trust in

mass-produced products or have come across alarming information about ingredients

online. Unfortunately, there’s a lot of misinformation out there, and many of us start

formulating with a skewed understanding of what’s safe and effective.

There are even apps designed to “analyze” ingredients in skincare products by

scanning a barcode. However, these apps often miss the mark by not considering

important factors like the percentage of the ingredient used or how it's applied. Both of

these factors drastically influence whether an ingredient is safe or harmful.

While I love and regularly use natural ingredients in my formulations, I’ve learned that

not all synthetics are bad—and sometimes they can be safer than natural alternatives.

There’s a lot more risk involved in DIY natural skincare than many people realize,

especially when beginners make some common mistakes. Below are some key errors

that new formulators often make and why they should be avoided.

1. Formulating with Food Ingredients

Using food-based ingredients in skincare formulations might seem appealing, especially

when you see items like coconut oil or honey in DIY recipes online. However, it’s

important to recognize that cosmetic-grade ingredients are processed differently than

food ingredients. Cosmetic-grade ingredients are preserved, tested for contamination,

and designed for topical use, whereas food ingredients are not.

While some big brands claim to use fresh fruits or other natural ingredients in their

products, they have the advantage of professional labs and testing to ensure the

product remains safe. Home formulators don’t have access to that level of testing,

meaning the risk of contamination is high when using raw food ingredients. In short,

mixing food with your skincare products at home can expose you (and anyone else

using your products) to potentially harmful contaminants.

2. Using Baking Soda in Skincare

Baking soda is a common DIY ingredient, often used in homemade deodorants or

exfoliants. However, it’s far too harsh for the skin. Baking soda has a high pH, which

can disrupt the skin’s natural pH balance, leading to irritation, rashes, or even chemical

burns. Over time, its abrasive texture can also damage the skin’s protective barrier,

making it more prone to acne, sensitivity, and other issues.

While it’s widely used for other household purposes, baking soda should not be

included in your skincare routine.

3. Using Essential Oils Incorrectly

Essential oils are often seen as safer alternatives to synthetic fragrances, but they are

powerful chemicals that must be used with caution. Each essential oil has its own

safety usage rate, which is important to follow. Using too much can cause skin

irritation, allergic reactions, or even long-term sensitization.

In fact, essential oils tend to cause skin irritation more frequently than synthetic

fragrance oils. This doesn’t mean they shouldn’t be used, but they must be used

correctly, with careful attention to dosage and dilution.

4. Making Your Own Botanical Extracts

DIY botanical extracts are a popular idea in the natural skincare community, but they

come with significant risks. Making your own extracts—whether in water, glycerin,

alcohol, or oil—can lead to contamination. The homemade extract might contain

bacteria, yeast, or other contaminants that could ruin your product and pose a health

risk. Moreover, you can’t control the potency of DIY extracts, so you might not be

getting the right concentration of beneficial compounds.

It’s far safer and more effective to purchase ready-made extracts from reliable suppliers,

where they’ve been processed and tested for safe, consistent use in skincare

formulations.

5. Using as Few Ingredients as Possible

While there’s a trend towards minimalist formulations, particularly for those who want to

“simplify” their skincare, it’s not always practical—especially when formulating

emulsions. Anhydrous products, which contain no water, can sometimes be formulated

with just a few ingredients, but emulsions (products that mix water and oil) require

additional components like emulsifiers, stabilizers, and preservatives to remain safe

and effective.

Some beginners try to avoid using these ingredients, but they are often essential for

product stability and safety. For example, natural emulsifiers usually require more

stabilizers than some synthetic emulsifiers, like Emulsifying Wax NF, which offers

built-in stability features.

6. Avoiding Preservatives

One of the most dangerous mistakes beginners make is refusing to use preservatives in

products that contain water. Water-based products are highly susceptible to microbial

contamination, which can lead to mold, bacteria, and yeast growth. This isn’t just

unpleasant—it’s a serious health risk.

A proper, broad-spectrum preservative is mandatory in any product that contains water

or could be exposed to it. Neglecting to use a preservative is not just risky, it can be

deadly. Protect yourself and your customers by using preservatives in your

water-containing formulations.

7. Using Vitamin E as a Preservative

There’s a common misconception that Vitamin E or Rosemary Extract can act as

preservatives, but this isn’t true. These ingredients are antioxidants, not preservatives.

Antioxidants help slow down the oxidation of oils, preventing them from going rancid,

but they do not prevent the growth of bacteria, mold, or yeast in a product.

For water-containing products, you need a proper preservative, not just an antioxidant..

8. Using Herbal Teas in Emulsions

Many people associate herbal teas with health benefits, and it’s easy to assume that

these benefits can be transferred to skincare by using herbal teas in place of water.

However, using herbal teas in lotions or other emulsions significantly increases the risk

of contamination. Herbal teas can introduce bacteria, yeast, or mold into your product,

and without professional testing or preservation, the contamination risk is high.

Instead of using herbal teas, consider using tea extracts from trusted suppliers, such

as green or black tea extracts from Formulator Sample Shop. These extracts provide all

the benefits of tea in a safe and controlled manner.

9. Using Beeswax as an Emulsifier

Beeswax is a popular ingredient for DIY skincare formulations, especially in balms and

creams. While beeswax is an excellent thickener for oil-based products and emulsions,

it is not an emulsifier. It cannot bind water and oil together to create a stable emulsion.

For emulsions, you need a proper emulsifier like Emulsifying Wax NF, which can

successfully combine the oil and water phases in a formulation.

10. Not Using a Thermometer

Temperature is critical in skincare formulation, particularly when making emulsions.

Many raw materials are heat-sensitive, and adding them at the wrong temperature can

compromise their effectiveness. For example, ingredients like Vitamin E, fragrance

oils, and essential oils should be added below 40°C to preserve their benefits.

If you're making hot-process emulsions, both the oil and water phases need to be

heated to specific temperatures, often between 70°C and 75°C, before being combined.

Additionally, the cool-down phase (where you add sensitive ingredients) must be below

40°C. Without a thermometer, it's impossible to know if you're working within the

required temperature ranges, which could result in ineffective products.

It’s recommended to have at least two thermometers on hand when formulating,

especially when working with temperature-sensitive ingredients.

Final Thoughts: Safety and Effectiveness First

While natural ingredients can be a wonderful addition to skincare, it's important to

remember that natural doesn’t always mean safe. In many cases, natural ingredients

can cause irritation or even harm if used incorrectly. Similarly, avoiding important

components like preservatives or emulsifiers can lead to unstable, unsafe products.

By avoiding these common mistakes, doing proper research, and using reliable

ingredients, you can create safe, effective, and natural skincare products that meet the

highest standards of quality.

Understanding Anhydrous Cosmetic Products: Their Role and Limitations

In the world of cosmetic formulation, one category of products that stands

out is anhydrous products. These are formulations that contain no water,

made entirely from oils, butters, waxes, and sometimes other oil-soluble

ingredients like esters and powders. While they are immensely popular for

their ability to soften, protect, and nourish the skin, it's essential to

understand both their benefits and limitations. One key limitation is that

anhydrous products do not provide hydration to the skin.

In this post, we'll dive deep into what anhydrous products are, how they

work, and why they should not be your sole skincare solution for extended

periods. We’ll also explain how they can aid in skin protection, improve

texture, and reduce trans-epidermal water loss (TEWL).

What Does Hydration Mean?

Before we explore anhydrous products, it’s crucial to understand the term

hydration as it relates to skincare. Hydration refers to the process of

adding water to the skin. Well-hydrated skin is supple, plump, and

healthy-looking. Hydrating products—often water-based—work to replenish

the skin’s moisture content by attracting water to the skin's outer layers.

Common hydrating ingredients include humectants like glycerin, hyaluronic

acid, and aloe vera, which draw water from the environment or from deeper

layers of the skin to the surface. Hydration is a critical aspect of skin health,

especially for those with dry, dehydrated, or compromised skin barriers.

Anhydrous Products and Their Purpose

Anhydrous literally means "without water." As a result, anhydrous

cosmetic products contain no water or aqueous ingredients. Examples of

popular anhydrous products include:

• Balms (lip balms, body balms)

• Butters (shea butter, cocoa butter-based products)

• Oils (facial oils, body oils)

• Ointments

• Solid oil cleansers (such as cleansing balms)

These products are packed with ingredients that act as emollients, which

are substances that soften and smooth the skin. Emollients help fill in the

tiny cracks between skin cells, improving texture and reducing roughness.

The Hydration Myth: Anhydrous Products Do Not Hydrate the Skin

While anhydrous products have numerous benefits, hydration is not one

of them. Since they contain no water, they are unable to deliver hydration

to the skin. This is a common misconception when people apply oil-based

products thinking they are moisturizing, when in reality, they are not adding

any water or moisture to the skin.

To clarify:

• Hydrating products add water to the skin.

• Moisturizing products help the skin retain moisture by creating a

  barrier that prevents water loss.

Anhydrous products fall into the moisturizing category because they create

a barrier on the skin that locks in moisture, reducing trans-epidermal

water loss (TEWL). However, they do not provide water themselves, and if

the skin is not hydrated before applying an anhydrous product, it may

eventually become drier over time.

If anhydrous products are used alone for extended periods without a

hydrating step, they can actually cause the skin to dry out. This happens

because, although these products trap existing moisture in the skin, they

are unable to replenish moisture levels. Over time, the skin’s natural water

content depletes, especially in environments with low humidity or when

exposed to heat, wind, or cold air.

For example, while applying an anhydrous balm may initially leave the skin

feeling soft and nourished, without adding water (via a hydrating serum or

mist), the skin may become parched as its internal water reserves are used

up.

How Anhydrous Products Help with Skin Softness and TEWL

Despite not hydrating the skin, anhydrous products still play an essential

role in skincare:

1. Skin Softening: Anhydrous products contain high levels of

emollients like oils, butters, and waxes that help soften and smooth

the skin. These emollients work by filling in the gaps between skin

cells, providing a smoother appearance and softer feel. This is why

they are so popular in products like lip balms and body butters, which

are intended to provide a luxurious, rich texture.

2. Protection from External Elements: Anhydrous products also serve

as a protective barrier on the skin, shielding it from environmental

aggressors like wind, cold, and pollutants. Since they contain no

water, they are often used in extreme climates to protect skin from

harsh environmental factors.

3. Reduction of TEWL: One of the primary functions of anhydrous

products is to help reduce trans-epidermal water loss (TEWL).

TEWL occurs when water evaporates from the skin into the

environment. Anhydrous products form an occlusive layer on the skin

that prevents this evaporation, keeping the water that’s already in

your skin from escaping. This is especially beneficial for individuals

with dry or sensitive skin, as it helps retain moisture.

While anhydrous products help reduce water loss, remember that

they don’t replenish water levels. This is why it's recommended to

layer an anhydrous product over a hydrating product to get the best

of both worlds.

How to Properly Use Anhydrous Products

To maximize the benefits of anhydrous products without experiencing

dryness, follow these steps:

1. Start with Hydration: Apply a hydrating product first, such as a

water-based serum or mist that contains humectants like hyaluronic

acid or glycerin. This will ensure that your skin is adequately hydrated

before applying the anhydrous product.

2. Seal in Moisture: After hydrating, apply the anhydrous product to

seal in the moisture and create a protective barrier. This step locks in

the water content provided by the previous hydration step, while also

softening the skin and reducing TEWL.

3. Limit Exclusive Use: Avoid using only anhydrous products for

extended periods without adding hydration, especially in dry or cold

climates where water loss from the skin can be more pronounced.

4. Perfect for Dry, Sensitive, or Compromised Skin: Anhydrous

products can be especially beneficial for those with compromised skin

barriers, eczema, or very dry skin. They offer a rich layer of protection

that prevents water from escaping and provides soothing emollients

that reduce irritation.

Conclusion: Understanding Anhydrous Products in Skincare

Anhydrous products, while beneficial for softening and protecting the skin,

are not designed to provide hydration. They can be a vital part of your

skincare routine, especially when it comes to reducing TEWL and offering a

protective barrier against environmental elements. However, they should

not be relied upon as a sole solution for moisturizing or hydrating the skin.

For best results, always pair an anhydrous product with a hydrating step to

maintain healthy, supple, and well-moisturized skin. By understanding the

limitations and benefits of these products, you can create a well-rounded

skincare routine that addresses both hydration and moisture retention.