Improving Your Shampoo Formula

Your shampoo formula is quite liquid because the surfactant system (ALS and Coco Betaine) requires a thickener to achieve a higher viscosity. The peppermint scent might also fade quickly in a wash-off product like shampoo.

Here's how you can adjust your formula:

1. Thickening the Shampoo

You can use a thickener to increase the viscosity. Two common options suitable for this type of formula are:

• Sodium Chloride (Salt): This is a very common and effective thickener for anionic and amphoteric surfactant systems like yours. It works by helping the surfactant micelles organize into a structure that increases viscosity.
  • Usage Rate: Typically added at 0.5% to 2%. Add it gradually while stirring until the desired thickness is achieved. Be careful not to add too much, as it can decrease viscosity again at higher concentrations.
• Xanthan Gum: This is a natural gum that forms a gel when dispersed in water. It's effective at low concentrations and can provide a stable thickness.
  • Usage Rate: Typically used at 0.1% to 1%. It needs to be properly dispersed in water (or glycerin/oil phase first) and hydrated to form a gel.

You can try adding Sodium Chloride first, as it's often sufficient for this type of formula and easier to incorporate. If you need additional thickness or different texture, Xanthan Gum can be used alone or in combination.

Revised Formula Structure (Example using Sodium Chloride):

• Water: ~63-64.5% (adjusted down slightly to make room for thickener)
• ALS: 23%
• Coco Betaine: 10%
• Sodium Chloride: 0.5-2% (add gradually)
• Peppermint scent: 1%
• Phenoxyethanol: 1%

Mix the water, ALS, and Coco Betaine first. Then, slowly add the Sodium Chloride while stirring until the desired viscosity is reached. Add the scent and preservative last.

2. Improving Scent Longevity

Peppermint oil is quite volatile, meaning its scent evaporates quickly, especially in a wash-off product. To improve scent longevity:

• Use a Fragrance Designed for Shampoo: Some fragrance oils are specifically formulated to perform better and last longer in shampoo bases.
• Consider Encapsulated Fragrances: These are special fragrance forms where the scent is trapped in a capsule that breaks during use, releasing the fragrance more effectively and for longer. However, these might be more complex to source and use.
• Slightly Increase Fragrance Concentration: You could try increasing the peppermint scent slightly (e.g., to 1.5% or 2%), but be mindful of potential skin sensitivity and regulatory limits.

Adjusting the formula with a thickener like Sodium Chloride or Xanthan Gum should help improve the texture and stability of your shampoo.