Bacon Grease Soap

Kevin woke up from a nap the other day, on a snowy Sunday, to find me in the kitchen. Surrounded by empty jars, everything coated in a thin sheen of rendered fat, totally absorbed in transforming bacon grease into something entirely new.

Tell me why this man was surprised?! I feel that rendering bacon fat to clarify it and turn it into soap is pretty on brand for yours truly.

I loved this transformation of what most would consider kitchen waste into something entirely functional and weirdly beautiful.

Jump to:

• Can You Really Make Bacon Grease Soap?
• Why Make Soap From Leftover Bacon Fat?
• Does It Stink?
• Preparing Bacon Grease For Soap Making
• Cold Process Soap
• Safety First!
• Tips and Tricks
• Ingredient Links
• Supply Links
• Step By Step Guide To Making Bacon Grease Soap:
• Recipe Notes
• Batch + Storage
• Soap Formula
• Comments

Can You Really Make Bacon Grease Soap?

YES!

After all, bacon grease is really just lard that's been cured and smoked.

We have been making our own homemade bacon for years now, and I must say, when you have amazing home cured and smoked bacon, you end up eating a lot more bacon. A side effect of eating a lot of bacon is cooking bacon and a growing number of bacon grease jars in the fridge.

Why Make Soap From Leftover Bacon Fat?

My recipe makes a bright white, hard bar with a fluffy, bubbly lather, moreso than my regular lard soap bars, likely due to the sugar and salt used in my bacon curing process, improving the lather.

The soap itself is gentle on your skin and leaves a nice clean feeling without being drying.

Does It Stink?

I make most of my soap unscented and this one is no different. The bar itself has a mildly smoked bacon scent, but leaves very little scent on the hands when used. I definitely don't mind the smell of the bar.

I keep my bacon fat soap in the kitchen, as much as the scent doesn't bother me, it's probably not one I'd use in the shower or on my face!

Preparing Bacon Grease For Soap Making

Preparing stored bacon grease it very similar to purifying rendered tallow - except it's already been melted once!

1. Scoop the bacon grease out of the storage jars and place it into a pot along with 1 cups of water and 1/2 tablespoon sea salt. If you're purifying large quantities of bacon grease, use a larger pot and add more water and salt keeping the 1 cup : 1 /2 tablespoon ratio.
2. Re-melt the grease and bring to a low simmer for 10-15 minutes. During the simmering, skim off any foam or impurities that float along the surface.
3. After simmering, strain the liquid into a clean stainless steel bowl and allow to harden in the fridge, at least until completely solidified. This will allow the fat and any remaining moisture to separate.
4. Once solidified, remove the fat disc from the surface and discard any remaining water. Scrape any impurities from the bottom of the fat, and repeat the process, adding water and salt until no impurities remain.
5. Once the water under the fat disc is clear and no impurities need to be scraped off, you can melt down the fat once more, without any water or salt, then transfer to storage jars until you're ready to make soap, or wipe the fat dry with paper towels, and chop it before transferring to a storage container. Keep this purified bacon grease in the fridge until you're ready to use it.

Cold Process Soap

I’m a big fan of cold process soap-making. Unlike hot process, which feels a bit rushed, cold process is slower and gives me time to enjoy the craft. Plus, it produces smooth, beautiful bars that feel luxurious on the skin.

The magic of soap-making lies in a process called saponification. This is the chemical reaction where the oils and fats in your formula mix with lye to create soap. With cold process, the soap cures over several weeks, allowing the reaction to complete fully and resulting in a gentle, skin-friendly bar. Sure, it requires a little patience, but I think it’s totally worth the wait.

Quick Overview Of The Steps:

1. Mix the lye solution
2. Weigh all of the oils and melt
3. Add lye solution to oils and mix until trace
4. Pour soap into molds and set 48 hours
5. Remove soap from molds and cure

Safety First!

When it comes to soap-making, safety has to be your top priority. Lye is no joke—it’s incredibly alkaline and can burn your skin or eyes on contact. That’s why I always make sure to suit up with rubber gloves and safety glasses before I even open the container.

If you do happen to get lye crystals or lye water on your skin, flush the area immediately with cold water until the burning sensation is completely gone. Don’t wait—it’s not something you can “tough out.”

If you spill the lye solution on a surface, you should mop it up with paper towels before rinsing them with cold water until diluted and then toss. Rinse the area with clean water several times to ensure the lye is completely and safely diluted. Lye crystals can be swept up and disposed of.

Mixing lye requires care and attention. Remember this rule: always add the lye to your water, not the other way around. Adding water to lye can cause an exothermic (heat producing) reaction that’s strong enough to make it erupt from the container. Nobody wants a surprise lye volcano!

A few other safety tips I live by:

• Soap solo: I always wait until the house is calm—no kids or pets running around—before I start. Even my teens are banned from the kitchen when I’m working with lye!
• Dedicated tools: I keep a set of tools just for soap-making. It’s so much easier than worrying about whether my kitchen items are clean enough. Over the years, I’ve gathered my soaping gear from thrift stores and garage sales. My most expensive piece? A $15 glass bowl with a pour spout that makes pouring soap into molds a breeze. My best score? A $2 immersion blender!

Tips and Tricks

If you’re new to working with lard soap, here are a few things I’ve learned along the way:

• Experimentation is key: lard works beautifully on its own, but it also plays well with others. I love combining it with oils like olive or coconut to customize the bar’s properties. While you can absolutely make soap with 100% lard, I like to add a small amount of other oils to enhance cleansing and improve the lather. Coconut oil, for example, increases bubbles and sudsing. That said, lard or bacon fat alone makes a perfectly fine soap if you’re aiming for simplicity.
• Always Measure by Weight: Soap-making requires precision, so measuring by weight is non-negotiable. Different oils, fats, and liquids have varying densities, making volume measurements unreliable. Weighing your ingredients ensures accuracy, consistency across batches, and—most importantly—a safe final product with the correct lye-to-oil ratio.
• Run Recipes Through a Soap Calculator: Whether you’re using my recipe or crafting your own, always plug your measurements into a soap calculator like SoapCalc or BrambleBerry’s Lye Calculator before starting. These tools double-check your oil-to-lye ratios to ensure proper saponification and safe end products.
• Don’t Skip the Curing Time: Cold process soap needs time to mature. During curing, excess water evaporates, the bars harden, and the saponification process fully completes. This curing period—typically 4 to 6 weeks—ensures your soap is gentle on the skin and long-lasting. If you rush and use your soap too early, it won’t perform as well and may break down quickly under use. Trust me, the wait is worth it!
• Soft Soap? If your soap is slightly soft when un-molding, you can allow it to set for another 24 hours, or you can pop the mold in the freezer for a couple of hours then remove from the mold.

Step By Step Guide To Making Bacon Grease Soap:

Gather Safety Supplies And Tools

1. Dig out the safety glasses and some rubber gloves. You'll need them later. Make sure to wear a long sleeved shirt and pants.
2. Find a heat proof bowl with at least a 2 quart capacity to mix your oils and a heat proof container for the lye solution with a capacity of at least 1 pint (500 ml).
3. Collect a silicone spatula, a scale, a double boiler, soap molds, an immersion blender, digital thermometer or infrared thermometer.

Make The Lye Solution

1. Put on your safety glasses and rubber gloves.
2. Weigh 190g cold water in a heat proof container with at least 500 ml capacity. I use a 2 cup glass pyrex jar. Weigh 71g lye crystals into a separate container.
3. Carefully pour the lye into the water and stir well. Steam, fumes, and heat are byproducts of this chemical reaction and are very normal, but be cautious to not burn yourself or inhale the fumes.
4. Set the lye somewhere safe to cool, in the kitchen sink is a great place - if it spills, it can be quickly and easily diluted.

Prepare The Fats + Oils

1. Meanwhile, in a heat proof mixing container, add 400g purified bacon grease and 100g coconut oil. Melt the solid oils and fats until completely liquified and combined. You can use a double boiler or the microwave - in 30 second bursts.

Make Bacon Soap!

1. Use your infrared thermometer to check the temperature of both the lye solution and oils. Once the lye solution is between 100 and 120f and the oils are within 10 degrees Fahrenheit, you can start soaping.
2. Pour the lye solution into the heated oils and carefully place your immersion blender into the mixture, ensuring the blending head is covered at all times. Alternate between pulsing the blender on and off and stirring the mixture with a spatula.
3. After pulsing and stirring for a while, the mixture will come to trace, which simply means it thickens. We're aiming for the consistency of pudding. You can tell it's come to trace by drizzling some of the soap batter on top of itself. If the drizzles stay and don't sink away instantly, you're in trace.

Transfer To Molds

1. Place the soap molds onto a tray or baking sheet.
2. Pour the soap batter into the molds. This recipe perfectly fills a 6 cavity soap mold plus one extra. For this recipe, I also made a round bar in my round mold from Michael's. If you only have one mold, you can always pour the rest into another mold or something from around the house, like an ice cube tray, juice box, milk carton, anything with a smooth, shiny surface that the soap will pop out of.
3. If desired, texture the top of the soap bars. You can use a spoon or a toothpick to add swirls. I added a row of coarse pink Himalayan salt for contrast.
4. Move the baking sheet somewhere that the soap can set for 48 hours.

Cure The Soap

1. After 48 hours, remove the soap from the molds. If the soap does not easily pull away from the edges of the molds, it may need longer to set, but after 48 hours, it should be firm enough to remove.
2. Use a peeler to remove the sharp edges from the sides of the soap bars.
3. Set the soap bars on end in a place with good airflow and allow to cure for at least 4 weeks. The curing time is very important when it comes to cold process soaps, this allows the saponification process to complete, excess moisture to evaporate and improves the longevity and lather of your soaps.

Recipe Notes

• Fast trace: Lard soaps can be really quick to reaching trace. to mitigate this for newer soapers, I have increased the water in the recipe - if you're an experienced soaper, you can always run the formula through your favorite soap calculator and reduce the water from 38% to closer to 30%.
• Additional oils: I like to add 20% coconut oil to my lard soap because when saponified it adds large fluffy bubbles, though you could absolutely make a 100% lard bar, but it won't have the same bubbly lather.
• 5% superfat: This means that 5% of the oils or fats in the recipe remain unsaponified, adding extra moisturizing and conditioning properties to the soap, making it gentler on the skin and better suited for everyday use, especially in dry or cold climates.
• Fragrance free: Working with fragrance oils or essential oils can alter how quickly a soap comes to trace, I opted to keep this soap unscented to keep the costs down, and because I love it's simplicity.
• Photos: Due to a camera malfunction I've borrowed some of the process shots for this article from my tallow soap guide - the process is very much the same, and the ingredients are similar.

Batch + Storage

Batch

This recipe is written to have nice round numbers versus a perfect bar amount - so it will fill 7 of the rectangle shaped bar soap molds, as linked in the supply section above. I find when you're just getting into soap making, this is a great sized batch - it allows you to make a reasonable amount of soap that you'll work through in a reasonable amount of time!

For this recipe, I also made a round bar in my round mold from Michael's.

Smaller batches also allow you to experiment more, as you'll have less soap to use up before you can try something new!

Storage

I keep my cured handmade soap in an old shoe box in the basement. This location is perfect because it's low humidity, temperature controlled, and away from direct sunlight.

The shelf life of your soap is long, and I personally find that the longer the cure, the better the soap, especially with formulas using a high volume of one oil.

Soap Formula

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