Help Me Pick % — Liquid Soap (KOH) Optimizer
How SoapMath Calculates Optimal Oil Ratios for Your KOH Recipe
Once you've chosen your oils for a KOH liquid soap recipe, getting the ratios right determines whether you end up with a clear, mild, well-lathering soap or a cloudy, harsh, or sticky one. The Help Me Pick % tool in the liquid soap section tests hundreds of percentage combinations and ranks the ones that best match your preferences across five liquid-soap-specific quality scores.
This guide covers each of the five KOH quality scores — what they measure, how they're calculated from fatty acid data, and what target ranges the optimizer aims for based on your preference answers.
How to Use Help Me Pick %
- Add Your Oils — Select KOH in the Soap Calculator and add at least 2 oils. The button appears automatically.
- Set Your Preferences — Walk through the same 4 steps as the oil wizard: clarity, lather, conditioning, and gentleness. If you used Help Me Pick Oils first, your preferences carry over.
- Review Suggested Formulas — Up to 3 ranked formulas appear showing percentages, all five KOH scores, fatty acid profile, and any warnings.
- Apply & Adjust — Click "Use This" to load a formula. Fine-tune by hand with live score updates.
The Five KOH Quality Scores
The optimizer evaluates every formula against 5 liquid-soap-specific properties. These are weighted averages calculated from the fatty acid profiles of the oils in your recipe, multiplied by their percentages.
SoapMath exclusive: These five KOH quality scores and the scoring system behind them were developed by SoapMath. They don't appear in standard soap-making references — purpose-built for KOH liquid soap formulation.
Cleansing
Lauric acid% + Myristic acid%. Measures oil-removal power. Too high = drying; too low = poor cleansing. Target varies from 8–30 depending on your gentleness and lather preferences.
Lather
Cleansing + Ricinoleic acid%. Measures total lather quality — both volume (from lauric/myristic) and creaminess/stability (from ricinoleic/castor oil). Target varies from 12–38 depending on your lather and gentleness preferences.
Mildness
Oleic% + Ricinoleic% + Linoleic%. How skin-friendly and conditioning the soap is. High-oleic oils (olive, avocado, canola) score highest. Target varies from 38–80 depending on your conditioning preference.
Clarity Risk
max(0, Palmitic% + Stearic% − 0.25 × Ricinoleic% − 0.10 × Oleic%). Predicts cloudiness and separation risk from solid fats. Lower is better. Target ceiling varies from 8 (clear) to 32 (opaque/cream) depending on your clarity preference.
Dilution Ease
Cleansing + Oleic% + Ricinoleic%. Predicts how readily the soap paste will dissolve in water during dilution. Below 40 is flagged as a potential problem. Olive-, castor-, and coconut-heavy recipes score highest.
The Four Preference Settings and Their Target Ranges
Your 4 preference choices control the target ranges the optimizer aims for. Here's exactly what each setting does to the targets.
Step 1: Clarity
Sets the ceiling for clarity risk and how heavily the optimizer penalizes formulas that exceed it.
| Selection | Clarity risk ceiling | Scoring weight |
|---|---|---|
| Clear Soap | <8 | 3× penalty for exceeding ceiling |
| Slightly Hazy OK | <16 | 1.5× penalty |
| Cream / Opaque | <32 | 0.5× (barely penalized) |
Step 2: Lather
Sets the target range for both cleansing and lather scores.
| Selection | Cleansing target | Lather target |
|---|---|---|
| Big Bubbles | 18–30 | 22–38 |
| Balanced | 12–24 | 16–30 |
| Creamy / Mild | 8–18 | 12–26 |
Step 3: Conditioning
Sets the mildness target range and its scoring weight.
| Selection | Mildness target | Scoring weight |
|---|---|---|
| Moisturizing | 58–80 | 2.5× (prioritized) |
| Balanced | 50–72 | 1.5× |
| Clean Feeling | 38–65 | 1.5× |
Step 4: Gentleness
Modifies the cleansing and lather targets up or down across all formulas.
| Selection | Adjustment |
|---|---|
| Gentle | −4 from both cleansing max and lather max |
| Balanced | No change |
| Deep Clean | +4 to both cleansing min and lather min |
How the Optimizer Works
Step 1: Generate Combinations
For 2–3 oils, the optimizer tests every 5% increment combination that totals 100% (e.g., 25/70/5, 20/73/7, 30/63/7). For 4+ oils, it uses structured sampling — dominant/fill-in patterns — to efficiently explore without testing an impractical number of combinations.
Step 2: Apply Oil Caps
Castor oil is automatically capped at 10%. Any recipe combination that would assign castor above 10% is adjusted by redistributing the excess to other oils proportionally.
Step 3: Calculate & Score
Each combination's 5 KOH scores are calculated as weighted averages from fatty acid data. Then a formula score is computed:
- • Cleansing target match: weight 2.0×
- • Lather target match: weight 1.5×
- • Mildness target match: weight 1.5× (or 2.5× if Moisturizing chosen)
- • Clarity risk within ceiling: weight varies 0.5× to 3.0× by clarity preference
- • Dilution ease bonus: up to +6 points for high dilution ease scores
Each score component uses a gradient: exactly in range earns full points; just outside earns partial; far outside earns zero or negative.
Step 4: Rank & Present
The top 3 highest-scoring distinct formulas are presented. Each shows the percentage breakdown, all 5 KOH scores with target ranges, the fatty acid profile, a formula description (e.g., "stays clear · good lather"), any rancidity or clarity warnings, and whether the formula is "In Range" (≥3 of 5 properties within target).
Warnings
High clarity risk — cloudy or thick soap likely
Appears when the blend's clarity risk exceeds your target ceiling by more than 10. Fix: swap to lower-clarity-risk oils (olive, sunflower, canola), or switch your clarity preference to Slightly Hazy or Opaque.
Cleansing score too high — may strip sensitive skin
Appears when cleansing exceeds the target max by more than 8. Fix: reduce the percentage of the foam oil (coconut, babassu), or switch your lather preference to Balanced or Creamy.
High linoleic/linolenic — rancidity risk
Appears when linoleic + linolenic combined exceeds 20%. These polyunsaturated fats oxidize quickly. Fix: swap high-linoleic oils (hemp, grapeseed, sunflower) for high-oleic alternatives (high-oleic sunflower, olive, canola), or add 0.1–0.5% vitamin E as an antioxidant.
Low mildness — consider more oleic-rich oil
Appears when mildness is more than 10 below the target minimum. Fix: increase the oleic-rich base oil (olive, avocado, canola) at the expense of the foam oil.
Tips for Best Results
- Start with a 2–3 oil recipe (foam oil + base oil + castor) for the clearest optimization results.
- If no formula is In Range, try your oil choices in the Help Me Pick Oils wizard first to get a well-matched starting set.
- Castor oil at 5–10% dramatically improves lather without raising cleansing — include it if possible.
- After applying a formula, test the live soap properties panel — adjust ratios by 5% at a time and watch all five scores update.
- Liquid soap with a dilution ease score below 40 may be difficult to dissolve during paste dilution — add some heat and use hot distilled water.
Frequently Asked Questions
Try the Liquid Soap % Optimizer
Select KOH in the Soap Calculator, add at least 2 oils, then click Help Me Pick % to find optimal ratios.