Making small test batches

Mar 31
3 min read

Updated: Apr 24

How to Make Small Test Batches of Soap for Colorants, Essential Oils & Recipe Experiments

Testing new soap colorants, essential oil blends, and recipe variations is essential for perfecting your handmade soap. However, making full-sized soap batches can be costly and wasteful if an experiment doesn’t turn out as planned. That’s where small test batches come in!

Why Make Small Test Batches of Soap?

Testing in small batches allows you to:

Experiment with natural colorants (e.g., indigo, spirulina, turmeric, and clays)
Try out essential oil blends without committing to large amounts
Adjust recipe formulations for better lather, hardness, or conditioning properties
Minimize ingredient waste if something doesn’t turn out as expected

By making small soap batches, you can perfect your cold process soap without breaking the bank.

Best Soap Batch Size for Testing Ingredients

Since essential oil and colorant usage rates are based on PPO (per pound of oils = 16 oz or 454 g), the best test batch sizes are:

8-ounce (1/2 lb or 227 g) oil batch → Use half of the recommended PPO
4-ounce (1/4 lb or 113 g) oil batch → Use one-quarter of the recommended PPO

Example: Testing Indigo Powder in Soap

If you want to see how 1 tsp PPO of indigo powder looks in soap:✅ Use ½ tsp for an 8-ounce oil batch✅ Use ¼ tsp for a 4-ounce oil batch

This method ensures accurate color testing while conserving ingredients.

Small Test Batch Soap Recipe (8 oz / 227 g Oils)

This balanced soap formula is great for testing natural colorants, essential oils, or new ingredient combinations.

Ingredients:

🧼 Oils & Butters:

4 oz (113 g) Olive Oil (50%)
2.5 oz (71 g) Coconut Oil (31%)
0.5 oz (14 g) Castor Oil (6%)
1 oz (28 g) Refined Shea and Cocoa Butter (13%)

🧼 Lye Solution:

1.13 oz (32 g) Lye (5% Superfat)
2.26 oz (64 g) Distilled Water (2:1 Water-to-Lye Ratio)

How to Scale the Recipe for a 4 oz (113 g) Oil Test Batch:

Simply divide the recipe in half for a 4-ounce oil test batch.

How to Make a Small Soap Test Batch

1️⃣ Prepare your lye solution by dissolving lye in distilled water. Allow it to cool.2️⃣ Weigh and melt your oils and butters, then let them cool to the same temperature as the lye solution.3️⃣ Blend lye solution with oils using a small immersion blender or a whisk.4️⃣ Pour the soap batter into small individual molds or small containers.5️⃣ Add your test ingredient (colourant, essential oil, etc.) and mix well.6️⃣ Cure & observe your soap as it hardens. Take notes on color, scent retention, and texture.

Evaluating Your Test Soap Batch

After curing, check the following:

✔ Did the essential oil scent last?

✔ Did the colorant hold up or fade over time?

✔ Would you adjust the ingredient ratio next time?

Keeping detailed notes will help you refine your soap-making technique and create consistent, high-quality handcrafted soap.

Why Small Test Batches Are Essential for Soap Makers

❤Making test batches of cold process soap is a great way to experiment, innovate, and perfect your recipes without wasting large amounts of natural soap-making ingredients. Whether you're testing essential oil blends, botanical colorants, or formulation tweaks, these small batches allow you to fine-tune your craft without unnecessary costs.