How to use SoapCalc
Important: after clicking Calculate Recipe, click View/Print Recipe to see lye and water amounts.
On that page all recipe information is arranged on a printable page without advertising.
- Adding an oil to your recipe.
- Specifying an oil involves 1) selecting a specific oil and 2) giving that oil a value; either a percent or weight. This can be done right after selecting a specific oil or after selecting all the oils in your recipe. See B.5 below for details on specifying a value.
- Select an oil from list of oils in the center. Values will appear in the leftmost column.
- Soap Qualities
- The approximate percentage of the fatty acids that will contribute to that particular quality in the soap bar.
- Iodine absorbtion value for the oil. The lower the number, the harder the soap bar.
- The INS value for the oil. Determined from the iodine and SAP values of an oil/fat. Ideal is considered to be about 160 but there is some leeway here.
- Fatty Acids The approximate percentage of each fatty acid in the oil.
- SAP Value (just below the oil list) The saponification value for the oil. Used to determine the amount of lye required for that oil.
- With an oil selected, double click on it or click one of the plus (+) buttons to add the oil to the 'Soap Recipe' list on the right. Doing the same with another oil will add it in the first open space on the list.
Selecting another oil from the list and clicking a plus(+) button opposite an oil in the 'Soap Recipe' list will replace that oil with the one selected in the oil list. Clicking the minus (-) button will remove the oil from the 'Soap Recipe' list.
- Design your soap. Overview: after your recipe has been defined, by the folowing 6 steps, the 'Calculate Recipe' button is clicked. If there is something missing, an alert will pop up explaining the problem and offering a solution if it is not obvious. If all is in order, the characteristics your Soap Recipe will be calculated: the soap bar qualities, fatty acid percentages and the staurated to unsaturated ratio will be displayed. Conversion from a weight based to a percentage based recipe will be performed. You can repeatedly make modifications and fine-tune your recipe, clicking 'Calculate Recipe' each time, until the recipe is just where you want it. Right after clicking 'Calculate Recipe', you can click the 'View/Print Recipe' button and view the recipe details and a graphical representation of the Soap Qualities and the Fatty Acid profile. (see D. 'View and Print your recipe.' below)
- Select which lye you will be using NaOH (Sodium Hydroxide) or KOH (Potassium Hydroxide)
- 'Weight of Oils' - Select the unit of weight you will use to specify your recipe quantities: Pounds, Ounces or Grams. (No matter which unit of weight you choose, the calculated recipe results will be displayed in all 3 - pounds, ounces and grams.)
- Enter the per cent of water in the recipe. If you are new to soapmaking, the default of 38% is recommended. After making a few batches you may want to gradually reduce this number to 33%. If you are an experienced soapmaker, you have the option of directly setting the 'Lye Concentration' or 'Water : Lye Ratio'
- 'Super Fat %' (lye discount) and 'Fragrance'
- Enter the per cent of 'Super Fat' also known as the lye discount.
- Fragrance Ratio: If you will be using fragrance, enter the fragrance ratio. If you are new to soapmaking, use 0.5 oz per lb of total oil weight or 31.25 gm per kg of total oil weight. This value does not need to be entered in order for the 'Calculate Recipe' button to work.
- Enter the value for each oil on your 'Soap Recipe' list. Use either a. or b.
- If you are using a percentage for each oil in your recipe, enter the percent of each oil in the '%' column. Total percent must equal 100% (rounded to 1/10 th of a percent). Also enter the total weight of all the oils you will use in 'Weight of Oils' text box. (FYI: One pound of oils will produce about 1.4 pounds of soap, plus or minus, depending on oils used, amount of water and additives.
- If you will be entering the weight of each oil in your recipe, enter the weight of each oil in the 'lb', 'oz' or 'gm' column. Do not fill in the 'Weight of Oils'. after 'Calculate Recipe' is clicked.
- Many times a recipe you see and like involves a quantity that is too much or too little for your needs. SoapCalc can be used to convert that recipe to percentages. Just follow these steps which are also found in Help Button #7 on the SoapCalc calculator.
- Click the round weight button (oz, lb or gm) at the top of the right column in the Recipe section.
- Enter the oils and weights.
- Fill in other necessary values and click 'Calculate Recipe'. Perentages will display in the % column.
- Click the round '%' button, select the recipe number, then click 'Save Recipe' (See section E below on saving a recipe).
- You can now set your own total 'Weight of Oils' for this recipe.
- Click the 'Calculate Recipe' button on the bottom. If there are no error messages, the soap bar qualities, fatty acid percentages and the staurated to unsaturated ratio will be displayed. Conversion from a weight based to a percentage based recipe will be performed.
- If there are messages, make the correction specified and click 'Calculate Recipe again.
- Note: If the ratio of Lye to Water in your recipe is too high to generally be considered safe (40% or greater), a warning will display. However, the calculation will complete.
- Preview soap bar qualities and fatty acid percentages.
- The 'All' column on the left under 'Soap Qualities' and 'Fatty Acids' now displays computed values based on the percentages of each oil and the recipe's combined oil qualities.
- The ratio of Saturated to Unsaturated oils/fats is displayed in the text box next to 'Sat : Unsat'
- If you entered weights for each oil, the total oil weight will show in the 'Weight of Oils' text box.
- If you entered a Fragrance Ratio, the amount of fragrance will display.
- View and Print your recipe. When you wish to see recipe details and a graphical representation of the soap bar qualities and fatty acid profile, click the 'View/Print Recipe' button. This button is active only after the 'Calculate Recipe' button has been clicked without any popup messages. The 'View/Print Recipe' page will either pop up as a new window or as a new tab (that is a browser setting). If you would like multiple new windows or tabs for each time you click 'View/Print Recipe' (i.e. to make comparisons), check the 'Multiple tabs' box next to the button.
- At the top of the 'View/Print Recipe' page is a summary of the recipe parameters.
- Then the total amount of lye and water required is displayed; in Pounds Ounces and Grams.
- Then the total amount of each oil is displayed; in Pounds Ounces and Grams.
- At the bottom of the page, a graphical representation of the Soap Qualities and a Fatty Acid profile can be displayed by clicking the 'Show Graph' button. If the graph is showing on the page it will print when the page prints. If it is not showing it will not print (click 'Hide Graph').
- To print the page, click your browser's File, then Print.
- Save your recipe.
- Your recipe can be saved as a Cookie on your Computer as long as nothing has been changed since the last time 'Calculate Recipe' was clicked without any messages.
- To save a recipe: Select a recipe name. Click Save
- To load a recipe on your next visit: Select a recipe
name. Click Load
- Sorry, the recipe names can not be changed.
Lye Safety Precautions before making your soap.
In order to save a recipe, cookies must be enabled on your browser.
Every reasonable attempt has been made to provide accurate
SAP numbers are averages based on values that have been obtained from various sources: the web, soapmaking books, oil/fat references. It is recommended that the superfat value be set to at least several
percent in the Soap Formulator - the default value is 5%.
Iodine values are averages of those available from various sources and are meant to be a general indicator for the hardness that the oil or fat will contribute to the soap. A lower iodine value will produce a harder soap. Some Iodine values are estimated.
The following is needed to add an oil to SoapCalc. If you'd like an oil added, it will speed up your request if you provide the following information with your request. Thank you.
- Name of the oil (alternate names would also be helpful)
- SAP (Preferably KOH SAP)
- Fatty Acid profile: per cent of lauric, linoleic, linolenic,
myristic, oleic, palmitic, ricinoleic, stearic.
- Iodine value
- INS (if available, if not it will be estimated from the iodine and
- 2 or 3 reliable references for the above information.