Essential Oil and Fragrance Oil 101 in Soap Making : How to Blend and Calculate Your Oil Combination | Mitchellia Sandra | Skillshare

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Essential Oil and Fragrance Oil 101 in Soap Making : How to Blend and Calculate Your Oil Combination

teacher avatar Mitchellia Sandra, Soap Maker and Designer

Watch this class and thousands more

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Taught by industry leaders & working professionals
Topics include illustration, design, photography, and more

Watch this class and thousands more

Get unlimited access to every class
Taught by industry leaders & working professionals
Topics include illustration, design, photography, and more

Lessons in This Class

8 Lessons (42m)
    • 1. Introduction

      1:29
    • 2. Class Project

      0:41
    • 3. The difference between essential oil and fragrance oil

      6:26
    • 4. Fragrance Notes

      6:02
    • 5. Fragrance Wheels

      6:46
    • 6. How to test your scent combination?

      4:37
    • 7. How to calculate your scented oil combination?

      13:54
    • 8. Time recommendation to combine scented oil with your soap mixture

      2:01
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About This Class

Do you ever have a thought about these :

"I have no idea how to combine the best essential oil/ fragrance oil in my soap batch"
"Is this amount of oil safe to use?"
"How to calculate the combination of the essential oil/ fragrance oil?"
and another statement that always ended up making you frustrated.

This kind of thought always haunts me every time I combine scented oil (fragrance and essential oil) in the past. I always almost ended up using one kind of essential oil in my soap batch.
But, after I learned more about scented oil and knew all its concepts, I realize it isn't that hard to determine. Because of that knowledge, I can choose, decide, and calculate my chosen scented oil combination easily.

Hello, my name is Sandra, a soap maker. This is my third class which will focus on essential oil and fragrance oil 101 to be used in soap making. I really want to share with you all of the knowledge that I have about scented oil. I hope this class can be a part of your soap making journey.

.

Here, you'll learn about :

  • The difference between essential oil and fragrance oil
  • Fragrance Notes
  • Fragrance Wheel
  • How to find and test your scented oil combination?
  • How to calculate your scented oil combination
  • Time recommendation to combine scented oil with your soap mixture

_______________________________________

If you need some basic knowledge about "how to make your cold process soap", you can access my first class on this link below :

Handmade Soap Making 101 and How to Make Your Own Cold Process Soap

_______________________________________

If you need some basic knowledge about "Cold Process Colorants", you can access this link below :

Basic Knowledge of Cold Process Soap Colorants and How to Use It

_______________________________________

Confetti Effect by Green Screen Wiki

Image (Presentation Slide Background) by rawpixel.com

Meet Your Teacher

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Mitchellia Sandra

Soap Maker and Designer

Teacher

Hi, I'm Sandra, a soap maker and designer. I love experimenting with soap ingredients and design! Creating soaps is a joyful experience, especially when you can give them to your loved ones. And I hope it can be something delightful for you to learn as well, thank you for visiting my profile!

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Transcripts

1. Introduction: Hello again everyone. My name is Sandra and I am a soap maker. Previously, I was making two classes that focus on cold process method. And today, I want to focus on a fragrance oil and essential oil that you can put on your soap. You can apply this knowledge to any method of soap making that you like. Years ago when I started to be a soap maker, I only add one type of essential oil into my batch. I don't feel confident enough to combine it with another scent because essential oil is so expensive. So, I just tried to play safe back then. But you know, the problem is by limiting it, I will limit the scent uniqueness and the function on my soap too. So here we go, I want to share with you all of my knowledge about scent, which hopefully can help you to make limitless scent creation. In this class, you will learn about the difference between essential oil and fragments oil, the fragrance notes and fragrance wheel for helping you determine your scent combination, how to find and test your scent combination? how to calculate your scented oil amount to your soap? and the best timing to put your scented oil on every soap-making method. Okay, great. Let's begin now. 2. Class Project: For the class project, you can try to create the best scent combination for your soap. You can use fragrance oil or essential oil and have fun with that. You can follow the way I search my combination as I share in our next lesson. Maybe you want to make your soap feel cool and masculine? or sweet and fresh? or anything you like. ou also can make a scent based on the benefit you want to put in your soap. Please, do share your combination in the project gallery. It will be great if we can share and inspire each other. So, let's begin now. 3. The difference between essential oil and fragrance oil: For our first lesson, we will start with the very basic knowledge about essential oil and fragrance oil. In every lesson in my class, I will call them "scented oil" for reducing the confusion. So, every time I say "scented oil", it means essential oil and fragrance oil. Back to our topic, in this lesson, we will focus on : The advantage and disadvantages of each scented oil. The advantage and disadvantages of each scented oil. The example of each scented oil. Before we start, I want to ask you something, which one is better: Essential Oil or Fragrance oil? And why did you choose them? If you are still confused about the answer, it's okay. I hope you can answer those after this lesson is done. Now, let's start talking about the difference between essential oil and fragrance oil The first one is where they come from. Essential oil is extracted from flowers, herbs, and plants. But, not all from nature can produce essential oil. Like, peach, strawberry, and chocolate. On the other hand, fragrance oil is a synthetic scent which a combination between natural ingredients and chemical components. That's why Essential Oil has fewer options than fragrance oil. Fragrance oil is not limited by the natural resources which produce essential oil. Next, let's talk about the shelf life. The essential oil has a long period shelf life which is around 2 - 15 years. In contrast, fragrance oil only can be good for use in 6-12 months. For checking the expired, you can notice it by their appearance and the aroma itself. For the essential oil, the smell is off, the colour will look different, oil becomes thickens and looks foggy, and the other bad thing is the benefit which essential oil normally have is gone. For the Fragrance oil, the smell is off and the aroma itself fade faster than normal. The other difference between essential oil and fragrance oil is the price. I am pretty sure, you already know about this fact. Essential oil is more expensive than fragrance oil. One of the reasons why essential oil has a higher price is the cost and the complexity of the essential oil's making process. Now, we will talk about the advantage and disadvantages of essential oil and fragrance oil. Here, you can see the advantages that you can get when using the essential oil on your soap. Essential oil is 100% pure from nature and has some benefits to us. It's long-lasting, which is great, so that we can keep them and use them at another time. Lastly, you can create a complex blend too with your essential oil. On the other hand, fragrance oil has more than 200 varieties, it can mimic the aroma that we have in our nature. Another good thing is this Oil is cheaper and affordable to buy. Fragrance oil is also safe to use. ou must know, some of the essential oil can harm your health, for example, rose essential oil which can harmful to pregnant women. So, if you still insist to have a product with a rose scent, you can change the rose essential oil with the rose fragrance oil. Because rose fragrance oil doesn't have any effect on medical issues here. Next, let's talk about the disadvantages of each scented oil. Like I shared before, the essential oil has fewer variants because not all in nature can produce the essential oil. The making process of essential oil is complex which makes it pricier to purchase and produce. Actually, not all the essential oil can be used also, because some of them can give an allergic or another negative effect on your health. So it's better to learn more about the essential oil you want to use before you purchase it. The last thing is essential oil's aroma can be faded easily due to the notes that they have. We will learn about notes later in our next lesson. On the other side, the disadvantages of fragrance oil are they don't have any medical benefit because they are synthetic and produce to mimic an aroma. Then, fragrance oil can accelerate or discolour the soap due to its components. Here, let's take a look at several examples for each scented oil. Maybe you are already familiar with these oils. So, which one is better: Essential Oil or Fragrance oil? and why did you choose them? For me, I will choose both of them because each scented oil can be complementary to the other. If you insist on me choosing one, maybe this is the right answer for me, I will choose essential oil as my main aroma because they have some benefit to the soap that I make. But I will choose the fragrance oil if the aroma doesn't exist in essential oil or if the essential oil that I want to use is too expensive for me. Let's see, jasmine essential oil. I will use jasmine fragrance oil than essential oil due to their price. Or in the case when the essential oil will harm someone who uses the soap I will change it into fragrance oil too. 4. Fragrance Notes: Great! Perhaps, you already know which scented oil category that you prefer the most. So, now, the question is, what are fragrance oil or essential oil do you need to combine or purchase? To answer that question, I will share with you some other basic knowledge that can help you more to select the correct scented oil for your soap recipe. In this lesson, we will learn about why you need to know about fragrance notes, what are notes, explanation about each kind of note: the top notes, the medium notes, and the base notes. Then, the last thing is the notes combination formula. Okay, in the beginning, we will talk about the scented oil notes or commonly known as fragrance notes. The reason why we need to know about it is you want to save up so much money and because you will get some clue or guide for searching your best-scented oil combination. Fragrance notes will show you how to combine each aroma which can cut off the searching time when you combine every aroma randomly. So, what are notes? Same as a musical note, fragrances have a note too. In music, when the singular note combines together, they will create a music symphony, because every note has a purpose. Now, imagine the singular note as a fragrance note and the music symphony as an aromatic symphony. In fragrance, notes are categories of every scent which are divided based on the aroma and lasting power. Fragrance notes are divided into 3 different notes. First is top notes or head notes, second is medium notes or heart notes, and third is base notes. The first aroma you will smell is the top notes, after the top notes start to fade away, you will smell the medium notes, then the last aroma, you will smell is the base notes. The base notes are the longest-lasting aroma. Now, let's talk more about the detail of each note. For a better understanding of the difference between top, medium, and base notes, I will use perfume as an example. First is Top Notes. Top notes are the first aroma that appears first after you spray perfume into your skin. These notes give the first impression to you, and have a purpose as initial aroma and smoothing the aroma before showing the next aroma. Same as when you are meeting a new friend, you will have the first impression of your new friend, right?. Top notes evaporate quickly and only last for the first five to fifteen minutes. Oh right, if you are curious, you can try using your perfume and spray it into your clothes. Now, try to sniff it, what is the first aroma do you get? Something special about top notes is they tend to feel fresh and sharp which is often described as light, refreshing, and happy. Here are several examples of top notes: Lemon, Lemongrass, Bergamot, and Peppermint Next is Medium Notes. After top notes fade away, the aroma of medium notes will be appearing. Medium notes retain the aroma of the top notes while gradually introducing a new aroma and as a buffer for the base notes which may not smell as pleasant on their own. These notes will stay longer than the top notes which are about 20-60 minutes. Right, try to sniff your clothes again, do you smell another aroma now? what is it? Medium notes have a characteristic too, they tend to feel pleasant and well-rounded. You can find these notes on ylang-ylang, rose, and jasmine. The last notes are Base Notes, the notes which linger the longest. Base Notes help boost the lighter notes while adding more depth and rich aroma. These notes will be lasting up to 6 hours. The characteristic of base notes is they tend to feel deep and rich, you can find these notes on sandalwood, cedarwood, vanilla, and amber. So, every perfume and aroma are a combination of notes. You can combine the notes vertically and horizontally. In horizontal combination, you can combine top notes + top notes + top notes. For example, you combine orange, peppermint, and tea tree essential oils. On the vertical combination, you can combine top notes + medium notes + base notes. Like when you try to combine lemon, rosemary, and cedarwood essential oils. For your information, we will learn more about the combination in the next lesson. Now the question, Is fragrance notes also have an impact on soap making? Yes, in perfume, you can smell every note after one another is fade away. This also happen on soap, even though is not as easy as a perfume to detect. 5. Fragrance Wheels: Right now, you already know about the fragrance notes And in this lesson, I will explain more about every scented oil category which you can combine. In this class, I will focus on sharing about scent wheel or we will call it as fragrance wheel. After this class, you'll know about what's the fragrance wheel, how to use the fragrance wheel, list of fragrance oil and essential oil in the fragrance wheel, and how to choose your scented oil to combine. So let's begin with what is the fragrance wheel. A fragrance wheel is a tool to help you determine the scented oil combination. Same as a colour wheel, the fragrance wheel is arranged by the relationship to one another. By using it, you will get an easier way to combine the scent you want. The fragrance wheel places scented oil into several categories based on the aroma and the ingredients inside them. This wheel is divided into four main categories which are oriental notes, which has a rich aroma with sweet and spicy notes. Woody notes, which is known as a warm aroma and earthy tones. Fresh notes, which is the most refreshing and vibrant aromas. and Floral notes which often considered feminine aroma. As you can see here, every main categories has its subcategories. Soft oriental, oriental, and woody oriental are included in Oriental notes. Mossy wood and dry wood are included in Woody notes. Citrus, water and green are included in the Fresh notes. Lastly, floral, soft floral, and floral oriental are included in Floral notes. So, how about woody, aromatic, and fruity here? You can say, woody as a part of oriental and woody notes. Aromatic as a part of woody and fresh notes, then fruity as a part of fresh and floral notes. Okay, now, let's discuss how to work with the fragrance wheel. This is the most common combination that you can use in your scent combination. I will share 3 kinds of combinations that I am always using. The first one is the combination within the same category. For example, we combine lemon, violet leaves, and berries that come from the Fresh notes. The second one is the combination that that happens between adjacent categories. For example, a combination of orange blossom from Floral Notes, with Frankincense from Oriental Notes. The third one is a triangle category combination. For example, you mix peppermint from Green Notes, Orange Blossom from Floral Oriental Notes, and Sandalwood from Mossy Wood Notes. Great, next, I want to share with you several scented oils on each note. You can get this list on the class resources. Here you can see all of the fragrance oil and essential oil which have already been divided based on their categories and subcategories. I also grouped each scented oil based on the notes that they have. You can use this list when you search your scented oil combination. So, the question is, what are fragrance oil or essential oil do you need to combine or purchase? Do you already know the answer? If yes, it's great!. If not, I will give you several questions which can help you determine the right scent for your soap. Let me tell you something, you can use your knowledge about fragrance notes and fragrance wheel here. The first question is, what kind of benefits do you want to put on your soap? The second question, what kind of scent do you want to get on your soap? And the last question is, what essential oil or fragrance oil which I can use to get that aroma and benefit? For a better understanding, I will give you the exact example of how I always searching the scented oil that I want. Here, I will not talk anything about the soap recipe, I will only talk about the aroma. Let's say, I want to make soap for acne treatment. So I will try to find essential oil instead of fragrance oil because fragrance oil doesn't have ny medical benefit. For the acne treatment, I need essential oil which has anti-inflammatory, antibacterial, and antiseptic properties. Then, I will determine what kind of aroma must exist on my soap. Here, I want to make a soap smell fresh and a bit woody and lemony. So, I will go to these lists for finding the right essential oil which has that aroma and benefit I want. To get to know about the benefits and properties of each scented oil, I always search it on Google by typing like this. Now, I get the best essential oil that I can use. All that essential oils, have the benefits that I looking for. I will take cedarwood essential oil from dry wood notes for woody aroma, lavender essential oil from aromatic notes to give a more fresh effect with a bit rustic feel, and lemon essential oil from citrus notes to give a lemony aroma. Here, you can see, I am using the vertical combination between adjacent categories. 6. How to test your scent combination?: Wow! Congratulations, you have already finished half of our class. Okay, now we will start to do some practical lesson. We will try to combine our selected scented oil and find our best combination. In this lesson, you will learn about what material do you need for scented oil testing, how do you test the scented oil combination, and example of aroma combination. Great, now, let's start talking about the materials that you need for finding your best combination. You need to prepare essential oil or fragrance oil. Cotton pads or cotton balls, here I'm using cotton pads for cosmetic use. Pipette (optional). Paper or notes to write down your experiment result. For experiement, I will use lemon, cedarwood, and lavender essential oil. Yes, I will do the vertical combination now. After you know what essential oil or fragrance oil that you want to use, we need to test it first so you will get the exact ratio for each scented oil. You need to determine how many drops of each scented oil so after they combine, they will have a good aroma. Now, take all of the material that you have already prepared. And here's the way that I always do. I will put a drop of each scented oil into this cotton pad. Now, mix it well like this. After that, try to sniff the cotton pad and try to figure out, what kind of aroma that you smell. Sometimes, you will find out one of the scented oil smells is too strong than the other or the smell is too weak than the other. If it isn't the aroma that you want to achieve, you just need to experiment again by adding or reducing the drops. In this experiment, I smell a lavender is a bit off so that the the aroma feels unbalanced. Because of that, I will try to put two drops of lavender essential oil and a drop of each lemon and cedarwood essential oil. Okay, I can feel this scent is more balanced now. I can smell a bit of lemony and flowery, with a deep scent from cedar too. Great, that's perfect!. Luckily, I can find a perfect combination with only two experiments. Sometimes we'll get the perfect one after several times of experiments, and that's common to happen. So, don't worry. So, here are several combinations that maybe you can try to. First, the horizontal combination between adjacent categories. You can try two drops of lemon essential oil, with one drop of peppermint essential oil, and one drop of tea tree essential oil. And another combination is the vertical combination between adjacent categories. You can try three drops of lemon essential oil, with one drop of cedarwood essential oil, and two drops of rosemary essential oil. Okay, for the next lesson, we will calculate the exact amount of each scented oil based on the total soap batch and the oil drops that we already get in this lesson's experiment. 7. How to calculate your scented oil combination?: Amazing! You already found your scented oil combination now. So, what's next? Yes, we must calculate the exact amount of each scented oil that can be used in our soap recipe. You know, we can not put the scented oil as much as we want because you will end irritate and rash your skin. Some scented oil can cause sensitization and photosensitivity, which is not good for your skin. Even though we know that essential oil is natural, It doesn't mean you can use it without a calculation. For example, some citrus essential oil can be phototoxic, which means they react with the UV light and can cause your skin to burn. So, overusing them in your soap recipe can be a big problem for your skin. That's why you still need to calculate it for making our standard so it's safe for the skin. Okay, so in this lesson, we will learn about safe usage rates, manual calculations, and digital calculations. Great. Let's get started now!. First of all, we must know about the safe usage rate, I will focus on soap product here. A safe usage rate is a safe amount of scented oil that can be used in our soap product. To know the exact safe usage rate, you must follow your country assessor regulation and IFRA document or you can say, International Fragrance Association document. Before we go to the next topic, let me explain first about the assessor regulation and IFRA document here. Assessor regulation is a rule in your country that you must be aware to follow, especially if you want to sell your soap product. Your product must be eligible and be assessed for sale. The regulation determines how much essential oil and fragrance oil can be permitted on your soap product. For example, in the UK, the assessor only permits up to 3% of fragrance oil or essential oil in a rinse-off product, or we can say here is a soap. The percentage is for the whole scented oil in your soap recipe, not just for one essential oil that you put in your soap. If you want to use orange essential oil and jasmine fragrance oil in your soap, it means the total amount of them must be 3% maximum. So, let's move on to the IFRA. IFRA is a document that has some information about the safe usage rate of fragrance oil to be used on soap and any other products. This document will show how much fragrance oil can come in contact with the skin without causing any irritation. But, you must know, different kinds of fragrance oil will have different IFRA, and different suppliers who sell the same fragrance oil, mostly have different IFRA too. Because different suppliers may use different chemicals when they are making the fragrance oil. For example, let's say last month you bought rose quartz fragrance oil in supplier A, then this month, you buy rose quartz fragrance oil in supplier B. Mostly, you will find out the safe usage rate of rose quartz fragrance oil in supplier A and supplier B are different. Like you see here, supplier A has a safe usage rate at 5%, but supplier B has a safe usage rate at 100%. So it's really important to check the IFRA document of the fragrance oil that you want to purchase. You can try to search in on your supplier website, or maybe you can ask your supplier. You must now, this IFRA document must be included when you take the assessment form because the assessor will check them too. Okay, now you know fragrance oil have IFRA, so, how about the Essential Oil?. The essential oil has the same component because they are 100% natural. So it doesn't matter if you buy essential oil from different suppliers, as long as they have the same inky name. It will not affect your assessment form at all. As you know, you can find the safe usage rate of each fragrance oil through their IFRA document. But for the essential oil, you can try to contact your assessor to get more detailed information about the safe usage rate. Now I will share with you an example of how to determine the maximum percentage of safe usage rate for your scented oil. In this case, we will use the UK assessment regulator which has a 3% maximum safe usage rate. Let's say we want to use pumpkin sandalwood fragrance oil from Bramble berry. To know about the safe usage rate, I will access this IFRA document which I can access through their website. Here, we can see the safe usage rate of each product. Soap making product itself is included in category 9. We can see here, the safe usage rate is thirty five point nine six 35.96%. Now the question is, does that mean we could use 35.96% of pumpkin sandalwood fragrance oil in our soap recipe? The answer is no. You must keep following the maximal percentage that your country assessor regulation had, which is 3% in this case. Now, let's take a look at other IFRA documents. In this IFRA document, you can see, this golden oats fragrance oil only can be used for 2.60%. So, could we add this fragrance oil to be 3% for our soap? No, we only can use a maximum of 2.60% in our soap recipe. Like I said before, overuse of scented oil can be harmful to your skin or will change your soap result. So, the conclusion is if the essential oil or fragrance oil has more than 3%, we only can use 3% maximum. If the essential oil or fragrance oil has less than 3%, so we need to stick it on that amount, we can not add it until it fulfils 3% maximum. If you insist to have 3% scented oil in your soap, you can add with another scented oil until it reaches 3% maximum. So that's all about the safe usage rate. Next, let's start calculating our essential oil or fragrance oil manually. To get an easier explanation, here I will use this essential oil ratio which we get in the previous lesson. We will use two drops of lavender essential oil, one drop of cedarwood essential oil, and one drop of lemon essential oil, as an example. If you check this website, let's say this is the valid essential oil safe usage rate from your country assessor. We know, it's eligible for using 5% lavender essential oil, 5% lemon essential oil, and 4% cedarwood essential oil. But, as I said before, we won't use that all in our soap. We only use the safe usage rate based on our country assessor regulation, for example, 3% maximum for the total scented oil. Okay, first, we need to calculate how much total fragrance or essential oil which we can use in our soap recipe. Here, we will use the assessor permitted safe usage, again, let say it's 3% maximum. If you use the cold process or hot process method, we need to multiply 3% with the total oil amount in our soap recipe. But, in the melt and pour method, we need to multiply that 3% by the total amount of melt and pour soap base. Let say here, we will use the cold process method and our total oil amount is 900 grams. For your information, the amount is exclude scented oil, water, decoration, and sodium hydroxide. So, it is only the oils, like coconut oil, butter, olive oil, and the other oils. Back to our topic. so, the total scented oil that can be used is 3% multiplied by 900 grams, will become 27 grams. Next, we must determine how much the percentage of each scented oil. The result of this calculation is to find out each scented oil percentage amount to the total scented oil be used in the soap. You already know, we use 2 drops of lavender, 1 drop of cedar, and 1 drop of lemon. If you add it, it will become four. Okay, to get the percentage of lavender essential oil, you only need to divide 2 with 4 then multiply it with 100. You will get 50%. For cedarwood, you can divide 1 with 4, then multiply it by 100. You will get 25%. Lemon EO has the same percentage as the cedarwood here because both of them have the same drop amount. The last is to know how much each fragrance or essential oil we can use in our recipe in grams or any other measurement unit you like. We already know, on the 27 grams total essential oil, it consists of 50% lavender essential oil 25 % cedarwood essential oil, and 25 percent lemon essential oil. So, to get each amount of grams on each essential oil, we only need to multiply the percentage by 27 grams. So the result will be lavender 13.5 grams, cedarwood 6.75 grams, and lemon 6.75 grams. Great, next, you must also know, you can calculate your scented oil by using the fragrance calculator on your supplier website. You can use that accurately only if you're buying your scented oil from that supplier. So, what if, you buy the essential oil or fragrance oil somewhere else? I think the calculation won't be effective and accurate because the IFRA things on each supplier can be different. One of the supplier which have the calculator is Bramble Berry. On this website, you only need to input the fragrance name, the product that you want to make, and the product batch. After you input that data, you will get the recommendation of the scented oil amount that you can use in your product. Like I said before, the result on the supplier website will be accurate if you also use their scented oil. If you use scented oil from different suppliers, in my opinion, the result of this calculation may be misleading because different supplier may have different IFRA documents. So the conclusion is, you need to know the assessor regulation in your country. the IFRA documents for the fragrance oil if you use it, and the safe usage rate of the essential oil information from your assessor. So that, you can get the scented oil safe usage rate and anyone can be safe when using your soap. What about the calculation? which one is better: Manual or Digital Calculation? From my perspective, both are good If your supplier has their own digital calculation, you can use them. But if they don't have any, you can do the manual calculation. 8. Time recommendation to combine scented oil with your soap mixture: Wow! This is our final lesson. I'm so happy you can go through the whole class with me. So in this lesson, I will tell you about when the best time you can add your scented oil in your soap making method. The first one is the cold process method. You can add your scented oil when your soap mixture reaches a light trace. You can see the visualization of light traces in this class on lessons ten. Next is the hot process method. You better add the scented oil, when your soap mixture is already cool to less than 180° F or 82° C. Adding the scented oil when the soap mixture is too hot, maybe around 200° F or 93° C and higher, will will make your scented oil vaporize. The last method, which we will talk about is the melt and poor method. In this method, you can add the scented oil when the soap temperature is between 140° to 150° Fahrenheit or 60° to 65° Celsius. Same as the hot process method, adding your scented oil to the hot soap mixture will lead your scented oil to vaporize. So it's better to avoid adding the scented oil when the soap temperature is more than 150° F. Congratulations, you did it!. You have already finished this class successfully. I hope you get something from what you searching for. Please, let me know if you want to discuss or share something with me. And I also have a class project that you can try too to share your best scent combination. It would be fantastic if we can share this together. Thank you so much for your participation. Have a nice day.