Help Understanding How Additives Are Calculated

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Jul 2, 2022
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New Zealand
Maybe a bit obvious but I have gotten myself confused over how to calculate additives in a recipe due to the way these explanations are written. This is mostly about melt and pour but also about some other bases this company does.

Melt and pour base SFIC the company says "A soap base can usually hold up to 5% of extra ingredients – in a 450 gram base this equates to approximately 22 grams of additional ingredients." so is that 450g plus 22g of extras or do you take the 22g off the 450g so 428g of base and 22g of additives.

Other bases:
Our DIY bases can be used to create your own bespoke skincare at home or for businesses. The bases can hold up to 5% of "added extra's"
Example Formula:

96g DIY Base

2g Carrier Oil

1g Extract/Clay/Exfoliant etc

1g Essential Oil/Fragrance

So is it 5% of the total volume/weight you want to make, or 5% of the amount of base you are using that is used to calculate the quantities of additives?
Nov 16, 2018
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Hamilton, New Zealand
5% of 450 is 22, so you just add the 22g on top of the 450g. For that sized batch I would add approx 10-12g of fragrance oil (depending on safe usage rate) so that leaves approx 10g of something else. If you are wanting to use something like jojoba oil or other special ingredient I would probably just add that and nothing else. 10g is only 2 teaspoons approx, so it's not enough to split with any other ingredients.
And please please don't add goat or other fresh milk as your 'additive'. They will go off in melt and pour soap. A local woman asked me to make some breast milk soap for her children to use (I make cold processed soap where the milk is 'preserved' in the chemical reaction between the lye and oils). Then nek minnit - she's set up her own business selling make your own kits with melt and pour base and telling people to add their own breast milk! And that's with 120g of breast milk to 550g of melt and pour base. Wouldn't want to smell that when it goes off - pooo!

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