Hemp Oil Soap Recipe: A Simple Guide for Beginners

Written & posted by Ingrid Ferris

Making soap from scratch is one of those projects that feels more complicated than it is. Once you understand the basics, a hemp oil soap recipe is genuinely beginner-friendly. You start with a handful of plant-based oils, add a few other ingredients, follow the process carefully, and end up with a handcrafted bar you can use every day.

This guide covers everything you need to get started: ingredients, equipment, lye safety, a simple cold-process method, and how to store your finished bars. Hemp seed oil is a popular choice for homemade soap because of its lightweight feel and fatty acid profile, and we’ll explain exactly how to use it well.

If you’d rather skip the DIY route and go straight to a finished hemp-based product, Myriam’s Hope Hemp has a range of topicals you can browse in the topicals shop, all backed by published lab results.

Before You Start: Hemp Seed Oil vs. Hemp Extract

When people search for a hemp oil soap recipe, they usually mean a recipe that uses hemp seed oil. That’s an important distinction. Hemp seed oil is pressed from the seeds of the hemp plant, not the flowers. It contains no cannabinoids. It’s rich in omega fatty acids, vitamins, and antioxidants, which is why it shows up in so many skin care products.

Hemp-derived botanical extracts like cannabidiol (CBD), CBG, CBN, CBDA, and CBDv come from the flowers and leaves of the plant. These are entirely different ingredients with different properties, different costs, and different formulation considerations.

Cold-process soap making involves lye and heat. It’s chemistry, not cosmetic blending. Finished tinctures are not interchangeable with soap-making oils. Always use cosmetic-grade hemp seed oil from a reputable supplier.

Why This Difference Matters in Soap

Hemp seed oil contributes to the fatty acid profile of your oil blend and affects the texture and feel of the finished bar. That’s its job in this recipe.

Cannabinoid content, if someone tried to add it, would be nearly impossible to measure accurately across individual bars. The soap-making process itself creates further complications, which we cover later in this post. For now, keep this recipe focused on hemp seed oil. That’s what makes it practical and repeatable.

Safety First: Working With Lye the Right Way

Cold-process soap requires sodium hydroxide, commonly called lye. There’s no way around this. Lye is what triggers saponification, the chemical reaction that turns oils into soap.

Lye is highly caustic. It can cause chemical burns on contact with skin and serious eye damage. Before you touch anything, put on your protective gear: gloves, safety glasses or goggles, a long-sleeve shirt, long pants, closed-toe shoes, and an apron. Work in a well-ventilated area because mixing lye with water releases fumes you should not breathe in.

Always add lye to water, never water to lye. The reverse can cause a dangerous reaction. Keep children and pets out of your workspace. Remove distractions. This step deserves your full attention.

Use 100% pure sodium hydroxide. Standard drain cleaners like Drano contain other ingredients and are not suitable for soap making. Dedicate your tools to soap making only, or clean them thoroughly according to soap-making standards.

Tools You’ll Need

Before you start, gather everything and lay it out. You’ll need a digital scale, heat-safe containers (a polypropylene jug works well for the lye solution), a stainless steel spoon or silicone spatula, an immersion blender, a thermometer, a soap mold, parchment or a silicone liner if your mold needs it, and your protective gear. pH strips are optional but useful after curing if you want to check the finished bars.

Simple Hemp Oil Soap Recipe for Beginners

This hemp oil soap recipe uses hemp seed oil as part of a balanced oil blend. A balanced blend is key. Using hemp seed oil as your only oil will give you a soft, unstable bar that goes rancid quickly.

The core ingredients for a beginner batch are hemp seed oil, olive oil, coconut oil, a hard butter like shea or cocoa butter, distilled water, and sodium hydroxide. Do not use tap water. Minerals in tap water can interfere with the saponification process.

Here’s the most important rule in this entire guide: do not use the lye amounts from any recipe you find online without running the numbers yourself. Every oil has a unique saponification value. Enter your exact oil types and weights into a reputable lye calculator like SoapMaking Friend or SoapCalc before you make a single batch. A 5% superfat is a good starting point for beginners. Measure everything by weight, not volume.

Suggested Oil Blend

Hemp seed oil is a lightweight oil that absorbs quickly and brings linoleic acid and other fatty acids to the formula. But it’s high in linoleic and linolenic acids, which means it can make a soft bar and is prone to going rancid faster if used in large amounts. Bramble Berry recommends keeping hemp seed oil at 1–15% of your total oil weight in cold-process soap.

Olive oil adds a mild, conditioning quality. Coconut oil supports lather and helps the bar firm up. Shea or cocoa butter adds hardness and a smooth feel on the skin. Together, these oils balance out what hemp seed oil can’t do on its own.

A starting point for a roughly 500g oil batch might look like this: 15% hemp seed oil, 30% olive oil, 35% coconut oil, and 20% shea butter. Run those numbers through your lye calculator before proceeding.

Optional Add-Ins for Scent and Texture

Once you reach light trace (explained below), you can add extras. Soap-safe essential oils like lavender, lemongrass, or eucalyptus work well. Finely ground oats, cosmetic clays, or small amounts of dried botanicals are also popular choices.

A few cautions: some botanicals will discolor or turn brown in cold-process soap. Some fragrance oils can cause the batter to seize up fast. Always verify that any additive is tested and approved for cold-process use before adding it to your batch.

Step-by-Step Cold-Process Method

Here’s the process from start to pour. Read through all the steps before you begin.

Step 1: Prepare Your Workspace

Lay out all your tools and pre-measure your ingredients into separate containers. Line your mold if needed. Put on all your protective gear before you open the lye. Make sure your ventilation is set up. Once you start, you want to move through the process without stopping to find things.

Step 2: Mix the Lye Solution

Slowly pour the sodium hydroxide into the distilled water while stirring. The mixture will heat up immediately and release fumes. Don’t lean over it. Set it in a safe spot to cool. You’ll combine it with the oils once both are within the temperature range your recipe specifies, typically somewhere between 90°F and 120°F, though this varies by formula.

Step 3: Melt and Combine the Oils

Melt your hard oils and butters first, either on the stovetop or in the microwave in short bursts. Once melted, add your liquid oils, including the hemp seed oil. Let the blend cool to the right temperature before combining with the lye solution.

Step 4: Blend to Trace

Slowly pour the lye solution into the oils while stirring. Then use your immersion blender in short bursts. Trace is when the mixture thickens enough that a drizzle on the surface leaves a faint trail before sinking back in. Light trace looks like thin pudding. This is the point to add your scent or other extras. Stir them in by hand rather than blending to avoid accelerating trace further.

Step 5: Pour, Set, and Unmold

Pour the batter into your mold. Tap it gently on the counter a few times to release air bubbles. Cover the mold if your recipe calls for it. Leave it undisturbed for at least 48 hours before unmolding. Cut the bars once they’re firm enough to hold their shape without crumbling.

Curing Your Hemp Soap Bars

Unmolding is not the finish line. Cold-process soap needs 4–6 weeks to cure. During this time, excess water evaporates and the bars become harder and longer lasting. Skipping or shortening the cure gives you a soft bar that dissolves fast in the shower.

Place your cut bars on a rack or tray with space between them so air can circulate. Keep them in a cool, dry spot out of direct sunlight. Turn the bars once a week so every side gets exposure to air. Don’t stack them tightly or seal them in containers during curing.

How to Store Finished Bars

Once cured, keep your bars away from standing water. A draining soap dish makes a real difference in how long a bar lasts. Store extra bars in a breathable wrap or an open box, not sealed plastic. Hemp seed oil has a relatively short shelf life compared to more stable oils, so smaller batches are a smart approach for home makers. Use your bars within a reasonable time and make fresh batches as needed.

Common Mistakes to Avoid

Most beginner problems come down to a handful of recurring errors. Measuring by volume instead of weight is one of the most common. In soap making, everything is measured by weight. A cup of coconut oil and a cup of olive oil weigh different amounts.

Skipping the lye calculator is the other big one. Using too much hemp seed oil (above 15–20% of total oils) can give you a soft, sticky bar that goes rancid fast. Adding fragrance oils not tested for cold process can cause the batter to seize. Unmolding before 48 hours, skipping the full cure, and storing bars in humid areas all lead to disappointing results.

Why a Lye Calculator Is Non-Negotiable

Every oil saponifies differently. Hemp seed oil has a NaOH SAP value of 0.135. Coconut oil is different. Olive oil is different again. If you swap one oil for another, or change the weight of any ingredient, the lye amount changes too. Too much lye makes a harsh, caustic bar. Too little leaves unreacted oils. Enter your exact recipe into a lye calculator every single time, even if you’ve made the recipe before and changed nothing. Mistakes in published recipes do happen.

Can You Add CBD Oil to Homemade Soap?

This is a question that comes up often, and the honest answer is: it’s not a good idea in cold-process soap.

Cannabidiol is a non-intoxicating, hemp-derived phytocannabinoid. But when it’s added to cold-process soap, it reacts with the lye and converts into a water-soluble salt. According to Bramble Berry, this gives CBD an even lower chance of absorption through the skin. The reaction also turns the batter a bright purple color. Beyond the chemistry, a rinse-off product is simply not the best use of a premium botanical extract.

As our CBD topicals guide explains, leave-on products like balms, creams, and salves are how hemp-derived compounds interact with the skin’s receptors most effectively. Homemade soap also can’t provide reliable cannabinoid content per bar, so there’s no way to know what you’re actually getting.

If you’re interested in hemp-derived topical products, browse Myriam’s Hope Hemp’s topicals collection and check the lab results for full transparency on what’s in each product.

When Ready-Made Hemp Products Make More Sense

Professionally made hemp products are formulated for consistency. The ingredient quality is controlled, the cannabinoid content is verified, and the formulation is designed to actually work as intended.

Myriam’s Hope Hemp offers tinctures, topicals, and specialized cannabinoid options including CBD, CBDA, CBG, and CBN. Every product is independently lab tested. You can read more in the educational resources section or review the certificates of analysis directly.

If you have questions about which hemp-derived product might suit your needs, the Leaf411 nurse hotline is a free resource staffed by cannabis-trained nurses. Call 844-LEAF411 (844-532-3411) and use code MHCBD to waive the consultation fee.

Labeling and Gifting Your Handmade Bars

If you’re making soap to give away, label each batch clearly. Include the date you made it, the main oils used, any scent added, and the cure date. A full ingredient list is good practice and appreciated by anyone with allergies or sensitivities.

Avoid making wellness claims on homemade products. Don’t describe your soap as treating, preventing, or addressing any skin condition. It’s a personal care item, and labeling it as anything more creates legal and regulatory problems.

Suggest that anyone trying a new personal care product do a small patch test on a limited area of skin before using it more broadly. That’s standard advice for any new cosmetic item, homemade or otherwise.

Bring Plant-Based Craft Into Your Daily Routine

A hemp oil soap recipe is a genuinely satisfying project. You’re working with plant-based oils, following a real chemical process, and ending up with something useful. Start with a small batch, measure everything by weight, run your numbers through a lye calculator, and give the bars the full cure time they need. Those four things will take you most of the way there.

And if you want hemp-based wellness support that goes beyond a bar of soap, Myriam’s Hope Hemp’s product shop, learning center, and lab results are good places to start.