How to Make Tallow Soap Tutorial

Have you heard all the hype about tallow lately? It is a great fat to use not only in our diet, but on our skin. Bar soap is making a comeback and leaving behind its old friend the plastic bottle. Let’s learn how to make our own tallow soap at home so you never have to worry about running out of soap again.

How to make tallow soap?

To make any cold-process soap, you will follow these basic steps (I’ll expand below):

1. Melt fats/oils together
2. Mix lye crystals with water until dissolved
3. Combine lye water and melted fats, stirring until it reaches “trace” (a pudding-like consistency)
4. Add any scents, mixing well
5. Pour soup into molds, cover, and let sit for 24-48 hours
6. Cut soap and store to cure for 4-6 weeks

Cold Process vs Hot Process in Soap-Making

Alright, get ready for some soap education. Soap-making is actually an easy process, and perfect for beginners. I remember when I first started making soap I was super overwhelmed with information, so I will try to keep it simple. If you like science experiments, or even if it’s not your thing, you’ll be so proud of yourself when you use your first bar of soap.

Cold Process is a traditional way to make soap where you combine your fats and lye at a lower temperature, closer to about 90-100°. It doesn’t take a lot of time (about an hour) to make soap this way and gives you more leeway in customizing colors and scents.

Hot Process uses heat as a way to make saponification happen faster, often within an hour as opposed to the 24-48 hours of cold process. This method requires more water than the cold process, but less essential oils and fragrance are needed. Hot process still requires weeks of curing but may be shorter than the 4-6 weeks recommended for cold process.

Saponification is the chemical process that converts fats into soap by way of sodium hydroxide (lye). This reaction is exothermic, so it gives off heat during the process.

I choose to use the cold-press method when I make soap because it is how I learned to make soaps, but learning to use the hot-process method is on my to-do list.

Can you make soap with castor oil, or other fats?

Yes, you sure can. I do not prefer a 100% pure tallow soap, although it is possible to make, and some people love it. Mixing my tallow with other fats and oils helps me achieve the soap properties I enjoy. I use castor oil in my Tallow Shampoo Bar Recipe.

What is a lye calculator?

You can mix and match many different fats and oils, but it is VERY important to use a lye calculator anytime you make soap. You should always double-check recipes, mine included, using a lye calculator before you make them. Use something like SoapCalc.net to help you calculate how much lye you will need for different ratios of ingredients. You cannot just swap castor oil for coconut oil in a soap recipe because every fat has a different SAP value (how much lye is needed to make a certain fat into soap).

Lye calculators help you to formulate the lye and water amounts needed for your combination and weight of oils to be able to saponify properly. It will also account for a “superfat” amount. Superfat is when a little extra fat is added to a recipe so that a little is left unsaponified to provide more hydration in a bar. I usually stick to a 5% superfat, sometimes going to 8% on special formulas.

You also want to make sure your soap isn’t either too cleansing (because it will dry your skin out), or too conditioning (because you’ll be left with a layer of scum on your skin). Each fat or oil also has different properties like lather or bubbles. My recommendation is to use a basic recipe and get good at it before you try new variations. This site is super helpful in understanding the different qualities of soaps and using the lye calculator.

Does tallow soap make a good lather?

I have had no complaints when it comes to a good lather with my tallow-based soap bars. I will say though, they aren’t as bubbly as some store-bought bars, but they are creamier in their lather. When you use SoapCalc.net it will provide you with the ranking of how much lather and bubbles your soap will have based on the amounts of different fats/oils.

Isn’t lye super dangerous, why would I wash my skin with it?

Actually, no lye is left in the product after the saponification process is completed. It takes about 24-48 hours for saponification to be completed, which is why we wait a day or two before cutting the bars. Of course, while making the soap you do not want to touch the lye, as it is caustic, or get it on your skin. So be sure to protect yourself during the process!

Can I naturally scent my soap?

Of course! Essential oils are often used in soap-making instead of fragrance oils. Using essential oils to get a strong scent will be a little more costly than synthetic fragrances. Depending on the recipe, it usually takes about 1-2oz of oils. You can always leave your soap unscented as well, works just as great. A little tip I came across many times in my research is that using a bit of clay in your soap recipe (like a couple of teaspoons) can help “anchor” the essential oils so they don’t get lost or fade as quickly. I will say the scent of essential oils will dissipate over time, but if you use it within a few months it will be just fine.

Why does soap need to cure for 4-6 weeks?

Good things come to those who wait. Technically, cold process soap is safe to use after only a few days. For a better bar of soap though, you’ll want all of the extra water to evaporate so your bar will become harder and long-lasting. We don’t want our soap to become a soft, mushy mess.

Is making homemade soap expensive?

Making soap is cost-effective for my family, especially if you keep it simple and don’t add in fancy essential oils or expensive butters. We can get tallow very inexpensively where we live, and the coconut and olive oils can be sourced at relatively low prices (usually Costco). One container of the lye I use has enough to make about 5-7 batches! You may only need to make 1 or 2 batches of soap a year for you and your family. Plus, if you have cured the bars properly, they last a really long time!

Let me teach you how to make tallow soap!

Supplies:

• Small Crockpot
• Stainless Steel Bowls
• Silicone Spatulas 
• Kitchen Scale
• Lye
• Soap Mold and Cutter
• Cookie Sheet
• Immersion Blender
• Infrared Thermometer 
• Protective Glasses and Gloves

This post contains affiliate links. As an Amazon associate, I earn from qualifying purchases. We only recommend products we personal use or have used and trust. If you choose to purchase through our amazon links in this post, we may receive a commission, at no extra cost to you.

Ingredients:

• 24oz Tallow (rendered)
• 8oz Coconut Oil
• 8oz Olive oil
• 5.67oz Lye (Sodium Hydroxide)
• 11.35oz Water 
• 1.25oz Essential oils (optional)

Instructions:

1. Organize your workspace and gather supplies, making sure it’s clean and clear of obstructions
2. Weight tallow, coconut oil, and olive oil
3. Melt tallow and oils together on warm setting in crockpot, until they reach around 120-130°
4. Put on protective gear and weigh lye amount, being sure not to touch any crystals
5. Weigh water into a separate stainless-steel bowl
6. Pour lye crystals into water (snow on a pond) in a well-ventilated area or outside, it will give off heat and fumes so keep your face away
7. Stir well and leave lye water to dissolve into a clear liquid for about 10-15 minutes
8. Pour heated tallow and oils into another stainless-steel bowl to cool slightly for about 15 minutes
9. Check the temperature of your lye and tallow continuously until they have both reached approx. 100° (it’s okay if lye is cooler than tallow), this can take another 15-20 minutes
10. Once lye and oils have cooled enough, pour lye mixture into oils
11. Keeping the immersion blender submerged, pulse for about 15 seconds, then use stick to stir the mixture, switching between pulsing and stirring a couple times (we don’t want a lot of air bubbles)
12. Check to see if the mixture is thickening and close to trace (see notes for what “trace” means) 
13. Repeat previous 2 steps until you reach medium trace. 
14. Add essential oils if desired and stir in well with spatula
15. Place mold on a cookie sheet
16. Pour soup batter into mold, tapping cookie sheet on counter to remove bubbles
17. Add design to top of soap using the back of a spoon or spatula if desired
18. Cover with wax paper or plastic wrap for 24-48 hours and if possible, wrap a cloth or towel around the mold to insulate
19. After 24-28 hours, remove from mold and cut bars to desired size, I get about 11 bars in a loaf
20. Store to cure for 4-6 weeks so that all remaining water evaporates, and bar hardens

Notes:

• Always run a soap recipe through a lye calculator — I use SoapCalc.net. 
• Wear eye and hand protection, you do not want to be splashed with lye or unsaponified soap. Long sleeves, pants, and shoes are great too.
• Do not have children nearby while making soap.
• We always use weight when measuring, not volume.
• Do not use any melt-and-pour soaps (pre-bought soap ingredients often in craft stores) in this process.
• ALWAYS pour lye into water. NEVER pour water into the lye. A hard pocket of undissolved crystals can occur, and you could end up with undissolved lye in your soap, or lye could explode out of your bowl. Be safe!
• Trace is when the soap mixture has emulsified to the stage of looking like pudding. Let some of the soap drop off the blender or a spatula, and you should be able to see it kind of sitting on top of the rest of the mixture.
• Cure soap in a dark, dry area
• Soda ash is a white, ashy film that can sometimes show up on soap when you go to cut it. It happens when unsaponified lye reacts with carbon dioxide in the air. The quality of soap is not diminished, and the soap is safe to use. There are tricks to get rid of it like steaming.
• Brambleberry is a great resource for beginner soap-makers
• Soap additives can include essential oils, clays, milks, honey, herbs, salt, coffee, etc.

Let’s Make Some Tallow Soap!

Weight tallow, coconut oil, and olive oil. Melt tallow and oils together on warm setting in crockpot, until they reach around 120-130°.

Put on protective gear and weigh lye amount, being sure not to touch any crystals. Weigh water into a separate stainless-steel bowl. Pour lye crystals into water (snow on a pond) in a well-ventilated area or outside, it will give off heat and fumes so keep your face away. Stir well and leave lye water to dissolve into a clear liquid for about 10-15 minutes.

Pour heated tallow and oils into another stainless-steel bowl to cool slightly for about 15 minutes. Check the temperature of your lye and tallow continuously until they have both reached approx. 100° (it’s okay if lye is cooler than tallow), this can take another 15-20 minutes.

Once lye and oils have cooled enough, pour lye mixture into oils. Keeping the immersion blender submerged, pulse for about 15 seconds, then use stick to stir the mixture, switching between pulsing and stirring a couple times (we don’t want a lot of air bubbles). Check to see if the mixture is thickening and close to trace (see notes for what “trace” means). Repeat previous 2 steps until you reach medium trace. Add essential oils if desired and stir in well with spatula.

Place mold on a cookie sheet and pour soup batter into mold, tapping cookie sheet on counter to remove bubbles. Add a design to the top of soap using the back of a spoon or spatula if desired.

Cover with wax paper or plastic wrap for 24-48 hours and if possible, wrap a cloth or towel around the mold to insulate. After 24-28 hours, remove from mold and cut bars to desired size, I get about 11 bars in a loaf. Store to cure for 4-6 weeks so that all remaining water evaporates, and bar hardens.

Check out our how-to for making Tallow Balms next.