Food additives in soap

[Mobjack Bay]

Ever since I made my cucumber and carrot soaps a few weeks ago, I’ve been thinking I should do some back of the envelope type calculations to put food additives into perspective. In addition, as I get more invested in my soap making, I do not want to be adding anything that enhances the chance of DOS. I thought I would share my quick assessment and numbers for others who have or are considering using food additives.

Most plant matter, purées included, contains a lot of water. It’s usually 90% or more of the “wet” (fresh) weight. That’s why we can use food additives to replace some or most of the liquid in a soap recipe. Water is fine in soap as long as the recipe is adjusted. When all of the water is removed, what’s left in plant matter is carbohydrates, proteins, fats, vitamins, minerals, etc. These are all commonly added to soap. Here are some examples:

• Carbohydrates - examples are starches, such as oatmeal (which also has fiber) and rice ; sugars, such as table sugar and honey
• Proteins - plant example is soy milk, and from animals we use goat milk and silk (amino acids)
• Fats - all kinds
• Vitamins - are often in the oils we use
• Minerals, Salts - examples are sea salt and they’re probably also introduced with the natural clays

If we assume 90% water content, 100 g of wet purée (3.5 oz) = 10 g dry purée. For comparison, 1 tsp of sugar weighs about 4 g. As an added bonus, many of the purées we use in soap also contain natural antioxidants. An example would be carnosic acid, a phytochemical antioxidant derived from rosemary and the star of ROE.

Consider carrot as an additive: Ten grams of dehydrated carrot is 80% carbohydrate (including sugars and fiber), 8% protein, 1.5% fat and 7% ash (mostly minerals, salts). It also contains Vit A and Vit E. I thought twice about the ash content. If all of the ash is salt, 100 g of wet carrot purée contains about 0.7 g of salt. That equals about 1/8th teaspoon of salt in the purée if a teaspoon of salt weighs 6 g. Thus, it looks as if carrot purée can contribute a little bit to the hardness of the soap.

 

[KiwiMoose]

Interesting - I am thinking of going down the pureed food route. Most likely a cucumber to start. But - yeah - not keen on DOS which I've managed to keep away from so far after 11 months of soaping.

 

[Mobjack Bay]

Interesting - I am thinking of going down the pureed food route. Most likely a cucumber to start. But - yeah - not keen on DOS which I've managed to keep away from so far after 11 months of soaping.

Putting it into perspective relative to the many things that get added to soap, cucumber is 90%+ water, a lot of fiber (but possibly less than what you end up with using oat milk), sugar, a little salt and some green plant pigment. Sound familiar?

 

[KiwiMoose]

Putting it into perspective relative to the many things that get added to soap, cucumber is 90%+ water, a lot of fiber (but possibly less than what you end up with using oat milk), sugar, a little salt and some green plant pigment. Sound familiar?

Aloe?

 

[Mobjack Bay]

Here’s what I found for fresh Aloe vera (Aloe barbadensis) gel. It’s close to 99% water and the dried gel is 25% glucose and 9% fructose. (Source). According to the source, “The gel consists primarily of water (> 98%) and polysaccharides such as pectin, cellulose, hemicellulose, glucomannan, acemannan,and mannose derivates. It also contains other kinds of sugars, vitamins, minerals and other compounds in very small quantities (source). For dried aloe powder one paper I found reported a 19.5% ash content (source). If I did the math right, that works out to 0.195 g 0f ash per 100 g of wet gel, which is close to what is shown in the table.