Water Replacements for Soap
Using Milks, Aloe, Beer, Tea & Other Liquids
Why Replace Water?
While distilled water works perfectly fine in soap, replacing some or all of it with other liquids can add unique properties, colors, and marketing appeal to your handmade soap. Milks add creaminess and natural sugars, aloe adds soothing properties, and teas can contribute antioxidants and subtle colors.
Benefits of Water Replacements:
- Milks add sugars that boost lather and creaminess
- Plant-based liquids can add subtle color and properties
- Create unique product stories for customers
- Some replacements have skin-soothing benefits
Using Water Replacements in the Calculator
The SoapMath calculator makes it easy to add water replacements to your recipe:
- Navigate to Step 5: Additives, Colorants & Water Replacements
- Check the box "I want to use a water replacement"
- Select your replacement type from the dropdown
- Enter the percentage of water to replace (e.g., 50% for half milk, half water)
- The calculator will automatically include your replacement in the INCI ingredient list
Pro Tip: Start with 50% replacement for your first attempt. This gives you the benefits while being more forgiving if something goes wrong.
Milk Replacements
Milks are the most popular water replacement due to the creamy lather they create. The natural sugars in milk boost bubbles, while the fats add conditioning.
| Milk Type | INCI Name | Properties |
|---|---|---|
| Goat Milk | Caprae Lac | Most popular; creamy lather, gentle, slight tan color |
| Cow Milk | Lac | Widely available; creamy lather, slight tan color |
| Sheep Milk | Ovis Aries Lac | Higher fat content; extra creamy, luxurious feel |
| Coconut Milk | Cocos Nucifera (Coconut) Milk | Vegan option; bubbly lather, stays whiter |
| Oat Milk | Avena Sativa (Oat) Milk | Vegan; soothing properties, gentle on skin |
| Buttermilk | Lactis Proteinum | Tangy, extra lactic acid; gentle exfoliation |
Critical: Freeze Your Milk!
Always freeze milk before adding lye to it. Lye generates intense heat that will scorch fresh milk, causing orange color and burnt smell. Freeze milk in ice cube trays, then add lye slowly to frozen cubes.
Plant-Based Replacements
| Replacement | INCI Name | Properties & Tips |
|---|---|---|
| Aloe Vera Juice | Aloe Barbadensis Leaf Juice | Soothing, moisturizing; use 100% pure juice; stays colorless |
| Green Tea | Camellia Sinensis Leaf Extract | Antioxidants; makes strong brew; may add greenish-brown tint |
| Rose Water | Rosa Damascena Flower Water | Subtle floral; hydrating; use pure rose hydrosol |
| Coffee | Coffea Arabica (Coffee) Seed Extract | Brown color; make strong brew; popular for kitchen soap |
| Cucumber Juice | Cucumis Sativus (Cucumber) Fruit Extract | Cooling, soothing; juice fresh cucumbers; stays light colored |
| Beer | Aqua, Hordeum Vulgare (Barley) Extract | Sugars boost lather; boil flat first to remove carbonation! |
Tips for Success
Temperature Control:
- Freeze milks before adding lye
- Add lye very slowly to frozen liquid
- Keep container in ice bath while mixing
- Work in a cool room if possible
Percentage Guidelines:
- 25-50%: Subtle benefits, easiest to work with
- 50-75%: Noticeable difference in lather and feel
- 100%: Maximum effect but requires more skill
Alternative: Milk Powders
If the freezing method seems intimidating, you can use milk powder as an additive instead. Add 1 tbsp per pound of oils to the oils before adding lye water. This gives similar benefits without the temperature concerns.
Troubleshooting Water Replacements
| If you see this... | What's happening... | Solution |
|---|---|---|
| Orange/brown milk soap | Milk got too hot when lye was added | Freeze milk solid; add lye more slowly; use ice bath; soap is still safe but color is affected |
| Burnt smell | Sugars in milk scorched from heat | Same as above; scent usually fades during cure; use more fragrance to cover |
| Soap overheated/volcaned | Sugars in replacement caused excess heat | Don't insulate milk soaps; put in refrigerator or cool spot; use higher water ratio |
| Unexpected color | Replacement reacted with lye or oils | Normal for many replacements; cosmetic only; test small batch first |
| Beer soap fizzed over | Beer wasn't flat before adding lye | Boil beer first to remove carbonation and alcohol; let cool completely before use |