Ghee solidifies unevenly due to variations in cooling rates and the different types of fats present, which crystallize at different temperatures. This results in a mottled or grainy appearance.
Ghee is primarily composed of saturated fats, along with smaller amounts of unsaturated fats and other compounds. When ghee cools, these different fats begin to solidify or crystallize. However, they don't all do so at the same temperature. Saturated fats tend to solidify at higher temperatures than unsaturated fats.
The rate of cooling also plays a significant role. If ghee cools slowly, larger crystals can form, leading to a grainier texture and uneven solidification. Rapid cooling, on the other hand, can result in smaller, more uniform crystals. Temperature fluctuations during the cooling process can also disrupt the crystallization process, leading to uneven solidification. The presence of moisture or impurities can also affect how the ghee solidifies. These factors combined contribute to the mottled or uneven appearance often observed in solidified ghee.
To promote more even solidification, cool ghee in a consistent, draft-free environment and avoid disturbing it while it sets.