Learn how to make small test batches of soap to try out new colorants, additives, and essential oil blends.
I will cover how to make test batches of soap for both cold process soap (CP) and melt and pour base (MP) in this article! 😊
I frequently get questions about adding various things to soap that I just haven’t tried yet, such as freeze dried raspberries, or ground fenugreek seeds.
My usual reply is that I haven’t tried that particular item myself, but the soapmaker could make a mini test batch and see what happens!
Small test batches of soap are the perfect way to try out a new colorant, essential oil blend, or recipe experiment, without wasting a bunch of ingredients, in case an idea doesn’t work out quite as planned.
The best part is that once you perform the experiment, you own that information firsthand. Whether it succeeds or fails, the knowledge will stick with you and help you grow as a soapmaker.
I’m a huge fan of making test batches! I’m always trying new ideas and experiments, and these little batches make it possible to do so, without breaking the bank. 😊
How to Size Your Test Batches – Cold Process Soap
Since colorant and essential oil rates are based on PPO — per pound of oil (16 ounces/454 grams) in a recipe — it works out best to make test batches with 8 ounces (1/2 pound) or 4 ounces (1/4 pound) of oil.
If you want to know how 1 tsp PPO of new-to-you colorant looks in soap, you could make a batch of soap with 8 ounces of oil in it, and use 1/2 tsp of the colorant.
Or, you could use 1/4 tsp of the new colorant in a recipe with 4 ounces of oil total in it, for a similar look/rate.
Another way to look at it:
1 tsp colorant could be used in a recipe with 16 ounces of oil
1/2 tsp colorant could be used in a recipe with 8 ounces of oil
1/4 tsp colorant could be used in a recipe with 4 ounces of oil
You can structure your test recipe however you like, but here’s one I often use:
CP Soap Test Recipe – 8 oz (227 g) Oils
(This recipe has 1/2 pound of oils in it.)
- 2.26 oz (64 g) distilled water (2:1 water:lye)
- 1.13 oz (32 g) lye (5% superfat)
- 4 oz (113 g) olive or rice bran oil (50%)
- 2.5 oz (71 g) coconut oil (31%)
- 0.5 oz (14 g) castor oil (6%)
- 1 oz (28 g) refined shea, cocoa, or kokum butter (13%)
You can also divide the recipe exactly in half, to make a 4 ounce (1/4 pound) oils test recipe.
Tips for Making Test Batches of Cold Process Soap
Use a small but tall and skinny container for mixing – a large yogurt container works well.
One quart plastic paint containers work well too.
You want to make sure your immersion blender is fully submerged, so a shallower container is not recommended.
Observe the test bars as they cure – do they hold color and scent well, is there anything you’d change?
If so, write it down to remember for next time.
My Soapmaking Journal is perfect for recording Cold Process Soap recipes & experiments!
Soapmaking Journal -Printable Digital Format
Get organized and inspired with this printable journal – it’s perfect for recording all of your soapy creations and notes!
How to Make Test Batches of Melt & Pour Soap
Not a cold process soapmaker? No worries! You can use the same idea, only with ready made soap base, instead of using lye, water, and oils.
What I do in that case is split the melt and pour base into an amount that’s easily divisible by 16. (Since there’s 16 ounces of base in a pound, and the additives are often figured at per pound of base.)
So if you find a guide that says to use 1 teaspoon rose clay per pound (16 oz) of base, you could divide those numbers by 4 and use:
1/4 teaspoon rose clay + 4 ounces of base
Or if you see a blend that calls for 3 grams of bergamot and 1 gram of rosemary for 16 ounces of base, that would be:
4 ounces of base (16 ounces divided by 4)
0.75 g bergamot (3 grams divided by 4)
0.25 g rosemary (1 gram divided by 4)
If your scale won’t measure that tiny of an amount, then you could use estimated teaspoon equivalents:
0.5 g essential oil is about 1/8 of a teaspoon
1 g is about 1/4 teaspoon
2 g is about 1/2 teaspoon and so forth
So the 0.25 g rosemary would = about 1/16 of a teaspoon,
and the 0.75 g of bergamot would = about 1/8 tsp + 1/16 tsp.
Coming soon – I’ll share an article on using essential oils in melt and pour soap. For cold process soapmaking, check out: 30 Essential Oils for Soapmaking + Printable Chart (cold process)