How to Check Soap Quality

There are several ways to determine a soap's quality, but these aren't the only ones. In this article, we'll go over Iodine value, Total fatty matter, pH test, and hardness rating. These numbers are just guidelines, not absolute standards. These numbers are based on the combined fatty acid content of the soap recipe, each of which contributes certain qualities to the finished product. These ranges are ideal for experimenting with soaps, though.

Iodine value

The iodine content of soapstocks depends largely on the crude oil used in the process. For example, high grade coconut oil may have a 9.5 iodine value while highly refined oils with higher free fatty acids can have values as low as 18.0. In general, however, higher-grade crude oils and more efficient refining processes will result in a higher iodine content in soapstock.

The iodine content of soap is measured by its INS value, or the number of grams of iodine adsorbable in a particular amount of fat. In general, the lower the iodine content, the harder the bar will be. Alternatively, a high iodine content will make the bar feel soft and moisturizing. But the amount of iodine in a soap bar depends on the type of oils and fats used in its manufacturing process.

Total fatty matter

One of the most important characteristics to look for when checking soap quality is the total fatty matter (TFM). This measurement demonstrates how much pure soap is present. This measure is usually calculated by conducting a chemical test, which decomposes the soap into fatty acids and weights them. While an estimation is acceptable, it is not accurate enough to be acceptable as documentation for a product's quality.

In the United States, total fatty matter (TFM) is measured on soaps in the same way that TSM is measured for food and beverage products. To test for TFM, wash a bar of soap with a TFM that is greater than seventy percent. Soaps that are higher than this are considered high-quality and can deep clean. As per the Bureau of Indian Standards (BIS), toilet soaps should have a minimum of 76% TFM.

pH test

If you're considering buying a new bar of liquid soap, you may be wondering how to do a pH test. The basic principle behind this test is that liquid soaps should be lower than their actual pH, but if they're higher than their pH, it's a red flag. This test requires a weak organic acid (such as citric acid) to neutralize the soap. However, you can also use this test to check for alkalinity.

The pH test is a vital part of the soap-making process. You might want to gift a bar of soap to a friend with sensitive skin, or even give it to a child. After all, you don't want to irritate their skin! Fortunately, there are two reliable PH testing methods that you can use to determine the pH of your soap. You can also use a pH meter if you're unsure about the quality of your soap.

Hardness rating

Soap's hardness rating indicates how quickly it will saponify and how resistant it is to softening. The higher the number, the harder the soap will be. This measurement comes from the amount of saturated oil in the recipe. Saturated oils are solid or semi-solid and contribute certain qualities to the finished soap. A lower hardness number means that the soap will soften and absorb water more readily during active use.

The penetration test is the most common method of testing soap hardness. It's a simple way to measure the force that a probe can apply to a sample of soap. However, the method does not give a precise measurement of hardness. The results may not reflect the quality of the actual soap in your home. In the first test, make sure your samples are room temperature and free from debris or other materials. Next, place the sample on a fixture base table and align the probe so that the aperture is directly beneath the surface of the jig. Be careful not to let the probe touch the base of the container or it will become overloaded and ineffective.

Total fatty acid content

The total fatty acid content of soap can be measured using the principal component analysis method. While free fatty acids make up a minor part of the soap, they can be a major determinant of quality and performance. The presence of saponified fatty acids in soaps can affect sensory perception and consumer preference. The data in Table 1 illustrate how fatty acids are used to formulate soaps. Saponified fatty acids are generally present in soaps that are produced using cold saponification or the use of additives.

In this test, the amount of each fatty acid was measured using standard curves for each fatty acid. The total fatty acid content of each soap was reported in mg/g.  

Soap price in Bangladesh is very low compared to other countries. However, although the soap price in Bangladesh is low, in terms of quality, very good quality soap is available in Bangladesh.