Help Me Pick % — Oil Percentage Optimizer
How SoapMath Calculates the Best Oil Ratios for Your Soap
Choosing which oils to use in soap is one thing — figuring out how much of each oil is the real challenge. Too much coconut oil and your soap is harsh. Too much olive oil and it takes forever to harden. The Help Me Pick % feature in the SoapMath soap calculator solves this by testing hundreds of percentage combinations and finding the ones that best match your preferences across four dimensions: bar hardness, lather type, skin conditioning, and cleansing strength.
This guide explains exactly how it works — from the preferences you set to the scoring system that ranks formulas — so you can make the most of this tool and understand why it suggests what it does.
How to Use Help Me Pick %
- Add Your Oils — Select at least 2 oils in the soap calculator. The button appears automatically once you have 2+ oils added to your recipe.
- Set Your Preferences — Walk through 4 quick steps: bar hardness, lather type, skin feel (conditioning), and cleansing strength. Options that conflict with your earlier choices are automatically grayed out with an explanation.
- Review Suggested Formulas — The optimizer shows up to 3 ranked formula options with percentages, calculated properties, and target range indicators.
- Apply & Adjust — Click "Use" on any formula to apply it to your recipe. You can then fine-tune percentages manually if you like.
The Four Preference Settings
You'll walk through 4 steps, one at a time. Each step shapes the target ranges for different soap properties. Some combinations are physically impossible — the tool automatically grays out conflicting options and explains why.
Step 1: Bar Hardness
Controls how firm or soft your finished soap bar will be. This is driven primarily by palmitic and stearic acid content in your oils.
Step 2: Lather Type
Controls the kind of lather your soap produces. This is driven by lauric, myristic, palmitic, and stearic acids.
Step 3: Skin Feel (Conditioning)
Controls how moisturizing the soap feels after use. Driven by oleic, linoleic, and linolenic acid content.
Step 4: Cleansing Strength
Controls how strongly the soap removes oils from skin. This interacts with lather type because both are driven by lauric acid content.
Why Some Options Are Grayed Out
Some soap qualities can't coexist because they depend on the same fatty acids pulling in opposite directions. When you pick a preference that conflicts with a later option, that option is automatically grayed out with an explanation. This prevents impossible formulas and saves you from confusing results.
Conflicts Explained
Very Hard Bar + Very Gentle Cleansing
Hard bars need oils high in palmitic and lauric acid (palm, coconut, tallow). Lauric acid is also the main driver of cleansing — so a very hard bar naturally has stronger cleansing power. You can't have both extreme hardness and ultra-gentle cleansing.
Soft Bar + Deep Clean
Soft bars are made with oils low in saturated fats (olive, avocado, sunflower). Deep cleansing requires high coconut or lauric-acid oils — which are also the hardest oils. A soft bar physically can't deep clean.
Soft Bar + Big Bubbles
Fluffy bubbles come from coconut and babassu oil (lauric acid). These same oils make bars harder. You can't get big bubbles from a recipe that's mostly soft oils.
Big Bubbles + Very Gentle
Big bubbles require high lauric acid, which is the same acid that drives cleansing. Bubbly soaps are inherently more cleansing — they can't be ultra-gentle at the same time.
Big Bubbles + Extra Moisturizing
High-lather oils (coconut, babassu) take up recipe space that would otherwise go to conditioning oils (olive, avocado). You can still pick "Moisturizing" — just not "Extra Moisturizing" with bubbly lather.
Creamy Lather + Deep Clean
Creamy lather comes from palmitic and stearic acid (tallow, palm, cocoa butter) — not lauric acid. Deep cleaning requires lauric acid. These two goals pull from different oil types.
Extra Moisturizing + Deep Clean
Extra moisturizing means lots of oleic-acid oils (olive, avocado), leaving little room for the coconut/lauric oils needed for deep cleansing. These goals directly compete for recipe space.
Clean Feeling + Very Gentle
"Clean feeling" means higher cleansing, which by definition is not ultra-gentle. You can get "Gentle" — just not "Very Gentle" with a clean-feeling bar.
What happens if you go back and change a previous answer? If your new choice creates a conflict with something you already selected in a later step, that later selection is automatically reset to "Balanced" — the safest middle-ground option. You'll see it when you get to that step.
The 7 Soap Properties
The optimizer evaluates every formula against 7 soap properties calculated from fatty acid profiles. Each property has a target range based on your preferences.
Hardness
How firm the bar is. Driven by palmitic + stearic acid. Higher = harder bar that lasts longer.
Cleansing
Ability to remove oils from skin. Driven by lauric + myristic acid. Too high can be drying.
Bubbly Lather
Big, fluffy bubbles. Driven by lauric + myristic acid. Coconut oil is the primary source.
Creamy Lather
Dense, lotion-like lather. Driven by palmitic + stearic + ricinoleic acid. Tallow and castor oil excel here.
Conditioning
Skin-feel after washing. Driven by oleic + linoleic + ricinoleic acid. Target: 44–69.
Iodine Value
Measures unsaturation (softness). Target: 41–70. Too high (>70) means soft soap prone to rancidity.
INS Value
General soap quality index. Target: 136–165. A rough guideline — not the most important metric.
How the Optimizer Works Behind the Scenes
Step 1: Generate Combinations
For 2–4 oils, the optimizer systematically tests every 5% increment combination that totals 100%. For example, with 3 oils, it tests combinations like 30/40/30, 25/50/25, 0/60/40, and hundreds more. Each oil can range from 0% up to its maximum soap-safe limit. For 5+ oils, it uses smart sampling strategies — dominant/secondary oil profiles and percentage shifts — to efficiently explore the best options without testing millions of combinations.
Step 2: Respect Oil Limits
Some oils have built-in maximum percentages based on best practice. Castor oil is capped at 10%, neem oil at 15%, and so on. The optimizer automatically enforces these limits, redistributing excess percentage to other oils when needed. If a combination can't be made valid, it's skipped.
Step 3: Calculate & Score
Each combination's 7 soap properties are calculated as weighted averages from published fatty acid data. Then each formula gets a score based on how close each property lands to the ideal point within its target range.
The scoring system weights properties differently based on all 4 of your preference choices:
- • Hardness always gets high weight (1.5×)
- • If you chose "Big Bubbles," bubbly lather gets 4× weight and cleansing gets 2×
- • If you chose "Creamy," creamy lather gets 4× weight
- • Your conditioning preference adjusts the conditioning target range and weight
- • Your cleansing strength preference adjusts the cleansing target range
- • Iodine and INS get standard weight (1×) — they're guidelines, not critical
Step 4: Rank & Present
The top 3 highest-scoring formulas are presented. Each shows the percentage breakdown, all 7 calculated properties with target ranges, and whether the formula is "In Range" (5+ properties within targets). Formulas are distinct from each other to give you meaningfully different options.
Understanding Warnings
When your oil selection can't fully achieve your preferences, the optimizer shows specific warnings with actionable suggestions.
Example: "Hardness: 24 is below 35"
This means even the best percentage combination can't reach the minimum hardness target. The fix: add a harder oil to your recipe (palm, tallow, cocoa butter) and re-run the optimizer.
Example: "Bubbly Lather: 12 is below 30"
Your oils don't have enough lauric/myristic acid for big bubbles. Add coconut oil, babassu oil, or palm kernel oil. Even castor oil at 5–8% gives a noticeable lather boost.
Key insight: Warnings don't mean your recipe is bad — they mean your current oil selection has strengths in other areas. You can accept the trade-off or add oils to address specific properties.
Tips for Best Results
Best Practices
- Use 3–5 oils for the most balanced results and fastest optimization
- Include at least one hard oil (coconut, palm, tallow) and one conditioning oil (olive, avocado, sweet almond)
- Add castor oil at any amount — the optimizer will keep it at a safe level automatically
- If no formula is "In Range," try changing one preference or adding a complementary oil
- After applying a formula, fine-tune by hand while watching the soap properties update live
Common Mistakes
- • Using only soft oils and expecting a very hard bar
- • Using only coconut oil and expecting creamy lather (it makes bubbly lather)
- • Adding too many oils (6+) expecting better results — simplicity often wins
- • Ignoring warnings about missing properties and wondering why the soap doesn't perform
- • Forgetting that superfat, water ratio, and cure time also affect the final bar
Example Walkthrough
Scenario: Everyday Bar Soap
You want a moderately hard bar with balanced lather. You've added these oils:
- • Olive Oil (conditioning, soft)
- • Coconut Oil, 76 deg (bubbly lather, hardness)
- • Palm Oil (hardness, creamy lather)
- • Castor Oil (lather booster)
You select Moderately Hard + Balanced lather and click "Calculate."
The optimizer might suggest something like: Olive 35%, Coconut 25%, Palm 35%, Castor 5% — producing hardness 42, bubbly 20, creamy 28, conditioning 50. All within target ranges.
Scenario: Gentle Facial Bar
You want a soft bar with creamy lather for sensitive skin:
- • Olive Oil (high conditioning)
- • Shea Butter (creamy, gentle)
- • Avocado Oil (moisturizing)
- • Coconut Oil, 76 deg (some cleansing)
Selecting Soft + Creamy might yield: Olive 40%, Shea 20%, Avocado 25%, Coconut 15% — a gentle, conditioning bar with low cleansing and rich creamy lather.