The Most Simple Tallow Soap Recipe

Prep Time

40 mins

Cure Time

30 days

Difficulty

2.0

Yield

1.0kg

If you're looking to dip your toes into traditional soap making, this single-oil tallow soap recipe is the perfect starting point. With just beef tallow, lye, and water, you'll create a hard, long-lasting bar that produces a creamy lather and leaves skin feeling clean without stripping away natural oils.

Want to make your own recipe? Check out our soap lye calculator.

Tallow soap has been a household staple for centuries, prized for its gentle cleansing properties and compatibility with sensitive skin. The fatty acid profile of beef tallow closely mimics our skin's natural sebum, making it an ideal choice for those seeking a simple, skin-friendly soap.

This recipe strips soap making down to its bare essentials—no fancy oils, no complicated calculations, just pure simplicity. While 100% tallow soap can present a few unique challenges (like fast trace and potential cracking), the straightforward nature of this recipe makes it ideal for beginners who want to understand the fundamentals before moving on to more complex formulations.

Whether you're rendering your own tallow from grass-fed beef or using store-bought, this recipe will yield approximately 1 kg of hard, white bars that improve with age. The optional additives—sodium lactate for easier unmolding, sugar for enhanced lather, and citric acid for chelation—can be included or omitted based on your preferences and experience level.

Ready to make soap the way your great-grandparents did? Let's get started with this time-tested recipe that proves sometimes the simplest approach is the best.

Cracking warning (and how to avoid it)

High internal heat expands the core and splits the top. Solutions: soap at moderate temps, avoid insulation, refrigerate if using sugars/milks/honey or if your room is warm. If you see a ridge forming, move the mold to a cooler spot.
Causes include too much sodium lactate or an aggressive water discount. Keep sodium lactate ≤3% of oils and don’t go ultra-low water with 100% tallow.

Troubleshooting (100% tallow specifics)

Stearic (white) spots / false trace

Cause: mixing too cool; high-stearic tallow begins to re-solidify.
Fix: fully melt, mix warm (~110–120°F), avoid big temp mismatches between oils & lye.

Soap seized or traced too fast

Keep temps moderate and minimize stick-blending—tallow is “fast” compared to high-oleic recipes. A 33% lye concentration helps, but don’t go so hot that it races.

Soda ash (white powdery surface)

Pour at light trace, keep batter warm and covered; a quick isopropyl alcohol mist on top can help. (Ash risk also drops with that ~33% lye concentration.)

Ingredients

Beef tallow — 684.6 g
Lye — 92.8 g
Distilled water —222.6 g

Instructions

Put on safety gear: goggles, gloves, long sleeves, and ensure good ventilation.
Fully melt tallow and keep at 110–120 °F (43–49 °C).
Dissolve sugar and citric acid (if using) in distilled water.
Slowly add sodium hydroxide to water, stir gently until clear.
Add sodium lactate to cooled lye solution (if using).
When both oils and lye solution are 110–120 °F, pour lye into oils.
Stick-blend to light or medium trace.
Pour into loaf mold and tap to remove air bubbles.
If using sugar/milk/honey or in warm ambient conditions, refrigerate 5–24 h to prevent cracking; otherwise leave at room temp without heavy insulation.
Unmold after 12–48 h.
Cure bars for 4–6 weeks before use.