Making Creams Part 2

In the previous article we looked at making a very simple cream following the 80:15:5 ratio for Water:Oil:Emulsifier. The formulation was just about as simple as it gets and here we're going to look at how we can tweak the basic recipe to improve the feel and stability of the cream

Emulsifiers will provide body to the cream but using emulsifiers on their own to thicken the cream is not ideal. There are a variety of materials available to the home formulator that can increase the viscosity of a simple emulsion.

Water Phase Thickeners

Are naturally derived polymers that work by absorbing water to swell up and increase viscosity. Cellulose derivatives like Hydroxyethylcellulose are frequently used in a variety of skincare products. Guar gum is another example of a naturally derived thickener. Others include Locust Bean Gum, and Xanthan Gum. There are many more but they may be difficult to source.

They are supplied as powders and are added to the water phase.

There will be many articles available explaining the best methods for incorporating these powders into the water phase – from first mixing the powder with a little glycerine, sprinkling onto cold water and allowing the polymers to swell before them using a high speed mixer to blend. Personally I simply sprinkle the powder into the heated water phase under the action of a high speed stick blender.

Water thickeners do not just build viscosity in the cream they also help stabilise the emulsion.

Xanthan – Readily available and easy to use. Usage rate is typically 0.5% to 1% though more can be used if desired. However above 1% Xanthan Gum can make your cream a bit stringy

Hydroxyethyl Cellulose (HEC) - not as commonly used as Xanthan but ought to be fairly easily available online. Usage rate is typically 0.5% to 1%. I prefer HEC to Xanthan as I find that creams using HEC as the water thickener have a nicer skin feel. HEC will also make crystal clear serums – if used at 1%. HEC will also tolerate alcohol very well and so can be used to make your own sterilsiing gel.

Guar Gum – is a highly effective water phase thickener that works well in creams. Use at 0.3% to 0.5%.

Ecogel - Lysolecithin (and) Sclerotium gum (and) Xanthan gum (and) Pullulan

is a relatively new addition to the range of water thickeners. It is in fact a blend of 4 thickeners which work synergistically to create a sophisticated multi-function agent. Not only will Ecogel act as a water thickener and emulsion stabiliser, it is capable of acting as an emulsifier. It is possible to create gel creams with a light and sophisticated skin feel. As a water thickener Ecogel can be used at between 0.3% and 1% and is compatible with a wide range of emulsifiers.

For more information click here:

Lecigel

is a gelling agent with emulsifying properties. It allows the increase in the viscosity and the stability of formulas. Suitable for both cold and hot processes, it also helps to adjust the viscosity at the end of the formulation process. Easy-to-use, it is compatible with most emulsifiers and is stable over a wide range of pH

For more information click here:

Oil Phase Thickeners

Tend to be selected from three groups of chemicals – Fatty Acids, Fatty Alcohols, and Butters.

(Note these 'acids' and 'alcohols' are not the same as we generally understand acid and alcohols).

There are a wide range of fatty acids and alcohols available for use in skincare but for the home formulator the following are usually easily available.

Stearic Acid (Fatty Acid) - can be derived from a variety of sources notably from natural butters such as shea and cocoa. Stearic Acid builds viscosity in a cream and also improves it's stability

Add to the heated oil phase at 1% to 2%.

Cetyl Alcohol (Fatty Alcohol) - Used as an emollient, thickener, or co-emulsifier in creams and lotions. It imparts texture and viscosity to creams and lotions. It is also used as an opacifier in shampoos. Please note that Cetyl Alcohol is not suitable for use as a stand alone emulsifier. It's role is to stabilise or thicken emulsions where a primary emulisifier (Emulsifying Wax blends, Olivem 1000 etc) is used.

Add to the Heated Oil Phase at 1% to 2% (3% can be used but tends to degrade the sensory feel of creams)

Cetyl Esters

Cetyl Esters is a blend of fatty alcohols and fatty acids that offer an easy way to increase the viscosity (thickness) of your creams and lotions while also improving the feel. The blend may include cetyl stearate, cetyl myristate, cetyl palmitate, myristyl myristate, and myristyl stearate. They are derived from vegetables,

Cetyl esters can be used anywhere you might use cetyl alcohol, although they will offer different qualities from the fatty alcohol. Using cetyl esters in a lotion or cream in the place of cetyl alcohol will give you a silkier feeling and a slightly thinner product. It will also lend stability to the emulsion.

Add to the heated oil phase at 1% to 2%.

Butters – because butters contain a high amount of stearic acid (and other fatty acids) for a more natural ingredients listing you can use plant derived butters (shea, cocoa, almond, etc) in the heated oil phase to add body to your cream. Using butters will give a more luxurious and richer feel to your cream. Bear in mind that butters should form part of the calculation for the oil phase. So if you are using 15% oil content and want to include say 2% Shea Butter reduce the liquid oils by the same amount. Limit the amount of butter to 3% as levels above 3% can make the cream feel grainy.

So let's trying modifying our basic formulation

Our original recipe was as follows

Water Phase
Water	80.00%	800g
Oil Phase
Sweet Almond Oil	10.00%	100g
Hazelnut Oil	5.00%	50g
Emulsifying Wax	5.00%	50g
	100.00%	1000g

We're going to use Xanthan at 0.5% as a water phase thickener and cetyl alcohol at 1% as an oil phase thickener. As we had used Emulsifying Wax at 5% to acts as the emulsifier and to provide body to the cream we are going to reduce it by 1% as the cetyl alchol will contribute thickness to the cream

Our new formulation is as follows

Water Phase
Water	79.50%	795g
Xanthan	0.50%	5g
Oil Phase
Sweet Almond Oil	10.00%	100g
Hazelnut Oil	5.00%	50g
Emulsifying Wax	4.00%	40g
Cetyl Alcohol	1.00%	10g
	100.00%	1000g

If we wanted to use butters in our formulation we would reduce the amount if oil by a proportionate amount and we could reduce the amount of cetyl alcohol a little to offset the extra body provided by the butter. Of course if we wanted a richer, thicker cream we could keep the cetyl alcohol at the same amount.

Water Phase
Water	79.70%	797g
Xanthan	0.50%	5g
	80.20%	802g
Oil Phase
Sweet Almond Oil	9.00%	9.00g
Hazelnut Oil	4.00%	40g
Shea Butter	2.00%	20g
Emulsifying Wax	4.00%	40g
Cetyl Alcohol	0.8%%	8g
	19.20%	192g
	100.00%	1000g

The best thing to do is to experiment. Try making small adjustments to the levels of oils, emulsifiers, and thickeners to obtain the viscosity and thickness you want.

Next article. Enhancing the cream – additional water phase and oil phase ingredients

How to make a simple cream

 

 

A cream or lotion is a combination of oil and water together with an agent (emulsifier) that stops the oil and water from repelling each other. In most cases the emulsifier also provides consistency and viscosity to the cream

 

Of course the process can be a lot more sophisticated and various other ingredients can be added to the basic oil + water + emulsifier recipe to affect sensorial attributes such as skin feel, fragrance and appearance. And of course it will be necessary to consider adding ingredients that will preserve your product.

 

This article is designed to provide a basic grounding in creating emulsions before we move on to more sophisticated formulations

 

 

Getting Started

 

Basic Equipment.

 

• Accurate scales (digital ideally) 
• Equipment to heat the water and oil phases (kitchen hob or microwave
• Saucepans or microwaveable jug
• Large jug or bowl (2 litre size if working in 1kg batches
• Thermometer (digital ideally
• High Speed Stick Blender.
• Gloves (Disposable latex ideally but clean marigolds are fine)
• Bottles or jars to hold finished product.
• Spatula

 

It is important that we can weigh the ingredients as accurately as possible and digital kitchen scales that can weigh in 1g increments allow far more accuracy.

  

For most formulations using simple and readily available emulsifiers, both the water phase and oil phase must be heated to about 75 C - 80C. You can use saucepans and heat the two phases on a kitchen hob or if you have microwave proof jugs or beakers you can use a microwave.

A digital thermometer is important to check the temperature of the two phases before blending. Most emulsifiers are fairly heat tolerant but there are several commonly used emulsifiers that do not appreciate very high temperatures. Ideally the water and oil phases will be heated to the same temperature.

 

A high speed stick blender is essential for blending the two phases together. Although it is theoretically possible to use a whisk to create an emulsion the energy and effort required to ensure a properly combined emulsion by hand is beyond many of us! Far easier to use a stick blender and the final product will be much more stable.

 

Preparing the equipment

 

It is important to ensure that all your equipment is sterile. Place bowls, jugs, pans in boiling water, most stick blenders will have a detachable head which can also be sterilised in boiling water. Milton's solution can be used to sterilise equipment but remember to rinse under cold water before use. Use an anti-bacterial surface cleanser to wipe down your work surfaces

 

 

Basic recipe

 

At it's most basic the ratio of water, oil, and emulsifier follows the 80:20 rule where the water component (water phase) represents 80% of the final product and oil and emulsifier (oil phase) represents 20% of the final product. The oil phase ratio is typically 75% oil and 25% emulsifier.

 

Or we can view the ratio as Water 80%, Oils 15%, Emulsifier 5%.

 

To make 1kg of product our basic recipe will therefore be

 

 

Water	800g
Oil	150g
Emulsifier	50g
	1000g (1kg)

 

Or halve the above amounts to make 500g

 

 

Which oil – which emulsifier?

 

We don't need to think too much about the water phase. But you could consider purchasing distilled water – not only will it be more sterile than tap water, but will have had various (undesirable) chemicals removed  

 

Oils are a matter of personal choice. There are numerous plant oils easily available in supermarkets and online. A future article will analyse the properties of various readily available plant oils in terms skin benefits but for now, I would recommend, while experimenting, using inexpensive and easily available oils such as sunflower oil (yes the one you cook with is fine for making creams), sweet almond oil, apricot oil, hazelnut oil, olive oil, and grapeseed oil. You may find that your local supermarket also stocks hazelnut oil, avocado oil, and walnut oil.

Feel free to blend various oils as long as you keep the total oil content at 15% or 150g per kg of finished product

 

There is a vast range of emulsifiers available to formulators. Some of these are quite sophisticated and require a level of experience and technical ability to work with. Fortunately tried and tested, simple to work with, and reliable emulsifiers are available online. One of the most popular emulsifiers is Emulsifying Wax. The name Emulsifying Wax is applied to several different blends of emulsifiers but here I am referring to Emulsifying Wax as – Cetearyl Alcohol and Polysorbate 60.

 

You will note from the chemical name that Emulsifying Wax is a blend of two ingredients. Ideally, and emulsion will be formed by two or more emulsifiers working together – a primary emulsifier and a secondary emulsifier – usually a high HLB emulsifier in tandem with a low HLB emulsifier 

 

I'm not going to go into the arcane world of HLB and how to calculate it here - it may be the subject of a future article. Rest assured that Emulsifying Wax has been blended to provide the optimal ratio of the two separate emulsifying agents so you don't need to worry about HLBs for now.

 

For this recipe I'm going to use a blend of Sweet Almond Oil and Hazelnut Oil

 

So our recipe will now look like this

 

Water Phase
Water	80.00%	800g
Oil Phase
Sweet Almond Oil	10.00%	100g
Hazelnut Oil	5.00%	50g
Emulsifying Wax	5.00%	50g
	100.00%	1000g

 

Method

• Weigh out the water phase and heat to 80C
• Weigh out the oil phase and heat to 80C
• Pour the heated water into your mixing jug.
• Slowly add the heated oil phase to the heated water phase while blending on highest speed setting.
• You will notice that the emulsion forms immediately as the two phases combine to a white lotion.
• Continue blending for 1 or 2 minutes on highest speed setting.
• Set aside to cool down.

 

Using a spatula or suitable implement (large slotted spoon works well) stir the emulsion occasionally while it is cooling. As the cream approached room temperature you will notice the cream thickens.

 

 

There you have it – your first DIY cream!

 

Check back for the next article as I'll be showing how to improve on this basic recipe.

Visit www.theformulary.co.uk for a selection of ingredients for making your own products.