Why Is Traditional Ghee Sometimes Grainy and Sometimes Creamy?

The role of milk fat crystallization and controlled industrial cooling

The core idea in the image is correct: the way ghee is cooled affects its texture. The scientific correction is that cooling changes the number, size and organization of the crystals and the proportion of crystallized fat, while the chemical composition of the milk fat stays the same under normal cooling conditions. Likewise, the fineness of the grains is not the same thing as the softness of the ghee. Ghee can feel smooth yet still be firm when scooped with a spoon.

First: What is the difference between grainy and creamy ghee?

1. Grainy (granular) ghee: Fat grains can be seen or felt when a sample is taken with a spoon. These grains form as crystals grow and aggregate within the liquid fraction of the fat. In a study comparing ten commercial products, mean grain size ranged from 0.200 to 0.330 mm after the samples were held at 29 °C for 24 hours. The quantity of grains also varied between samples, showing that grain size and grain density are two distinct attributes.
2. Creamy or smooth ghee: It looks more homogeneous because the grains are less visible or the crystals are finer. How easily it spreads or scoops depends on the amount of solid fat and the strength of the crystal network at the temperature of use. So when two containers are compared, both should be examined after being conditioned at the same temperature.

Both grainy and smooth textures can occur in milk ghee itself. The Codex annex describes its texture as ranging from smooth and finely granular to liquid, depending on temperature. Appearance alone is not enough to judge the purity of ghee or the source of its fat.

Second: What does cooling do inside ghee?

Milk fat consists mainly of a mixture of triglycerides that differ in their melting and crystallization temperatures. During cooling, crystal nuclei form, the crystals then grow, and they may aggregate into the grains we see in the container. At the same time, part of the fat remains liquid. Texture is therefore determined by the interplay of crystal size, crystal aggregation and solid fat content.

1. Faster cooling, when two cooling paths are compared on the same raw material, tends to form more crystal nuclei in a shorter time, so the structure is usually finer and less grainy. However, Campos and colleagues found that anhydrous milk fat cooled rapidly in their experiment was harder and had a higher solid fat content than the slowly cooled sample. A “creamy” appearance is therefore not enough to predict hardness.
2. Slower cooling, or holding at a suitable temperature after initial cooling, allows more distinct grains to grow under the right conditions. In a direct study on ghee, mean grain size in the control sample was 0.236 mm at 29 °C after 24 hours, while the highest grain yield within the study conditions was recorded at 26 °C. The difference matters to the plant, because the temperature that gives the largest quantity of grains may differ from the one that gives the desired grain size.

Third: Why does texture differ between two batches on the same line?

1. Raw fat composition. Differences in the proportions of high- and low-melting fractions change graininess. In the published comparison of commercial ghee, weakly grainy samples resembled blends richer in the low-melting fraction, while samples with larger grains resembled blends richer in the high-melting fraction. This is why the butter or cream source is kept constant in texture-control trials.
2. Agitation during crystallization. The effect of agitation depends on its intensity, its timing and the fat temperature. X-ray diffraction experiments have shown that shear can alter crystallization kinetics and transitions between polymorphic forms. In practice, record the mixer speed and when it is switched on and off, especially after crystallization has begun.
3. Ghee temperature inside the container. The cold-room temperature is an equipment set point; what should be compared when fill weight or container arrangement changes is the core-temperature curve of the container. This is an important operational inference, because cooling rate and holding time affect the crystal structure.
4. Holding time and storage conditions. Crystal transformations may continue after initial cooling. A sample from each trial is therefore evaluated after a defined period, then re-examined during storage under conditions that represent actual distribution.

Fourth: How do we control texture in the plant?

The trial starts with a single batch of clarified ghee. In some routes for making ghee from butter, manufacturing guidelines cite a range of 110–120 °C for the heating stage, moisture removal and flavor development, followed by separation of the residue by filtration or clarification. This range applies to specific manufacturing routes; the texture trial itself begins after clarification, with the cooking stage kept identical for all samples.

To produce grainy ghee

1. Divide the batch into containers that are identical in material, size and fill weight.
2. Start by comparing holding temperatures of 26 and 29 °C, with evaluation after 24 hours. These are test points based on ghee studies and need to be validated against the plant’s formulation and container size.
3. In the first round, keep the filling method constant and let the samples settle undisturbed during holding, so that the effect of temperature alone can be read.
4. Choose the program based on grain uniformity, grain size, the amount of visible free fat and ease of scooping. Cooling under the plant’s variable ambient conditions makes it hard to reproduce the result from batch to batch.

To produce smooth, creamy ghee

1. Using part of the same batch, compare a faster, controlled cooling path with the plant’s reference cooling path, and record the temperature inside the product over time.
2. After choosing a path that gives fine grains, test controlled agitation in a separate trial if you need to improve homogeneity.
3. Measure smoothness and hardness separately at the display or use temperature. The faster path may give a finer texture with higher hardness, so the program is approved on the basis of both measurements.

For quality control, it is enough at the start of development to document grain images at a fixed magnification, measure hardness by a penetration test at a defined temperature, and record separation of liquid fat. When differences between seemingly similar batches need explaining, polarized light microscopy can be used to study the crystals, DSC to study crystallization and melting, and solid fat content (SFC) measured at defined temperatures. Composition and oxidation tests, such as milk fat content and peroxide value, remain separate from texture acceptance.

Fifth: Does ghee need additives to control texture?

A grainy or smooth texture can be developed by controlling crystallization itself. Codex CXS 280-1973 defines ghee as a product obtained from milk, cream or butter by removing most of the water and non-fat solids, and sets a minimum milk fat content of 99.6% by weight. It is important to distinguish between a substance’s ability to affect crystallization and permission to use it in a product bearing the name milk ghee. One example is mono- and diglycerides (INS 471). It appears in the Codex database on the page for food category 02.1.1, but Note 507 restricts that listing to products conforming to CXS 19-1981. Its appearance on the page is therefore not an authorization to add it to ghee conforming to CXS 280-1973. The standard of the country of sale should be checked when the formulation is approved.

Conclusion

When targeting grainy ghee, control the holding temperature and time to form distinct, uniform grains. When targeting creamy ghee, control the cooling rate to obtain a finer structure, then check scoopability at the temperature of use. In both cases, base the operating program on the product temperature inside the container and the texture after it has stabilized.

Key References

1. Rachana, C. R., Nath, B. S., Reshma, M. V., & Armughan, C. (2013). Variation in grainy texture of commercial ghee in relation to laboratory ghee and its blends. International Journal of Dairy Technology, 66, 90–97.
2. Effect of cholesterol removal on the granulation behaviour of low-cholesterol ghee. International Journal of Dairy Technology.
3. Lopez, C., Lesieur, P., Bourgaux, C., & Ollivon, M. (2005). Thermal and structural behavior of anhydrous milk fat. 3. Influence of cooling rate. Journal of Dairy Science, 88, 511–526.
4. Campos, R., Narine, S. S., & Marangoni, A. G. Effect of cooling rate on the structure and mechanical properties of milk fat and lard. Food Research International.
5. Codex Alimentarius. Standard for Milkfat Products, CXS 280-1973, and General Standard for Food Additives, CXS 192-1995.
6. National Dairy Development Board. Standard Operating Procedure for Ghee Processing.