# Why does milk clot while making yogurt?

Why does milk clot when it becomes yogurt? Is it only because of the decrease in the $\mathrm{pH}$ of milk? If it does so, what is happening when I increase the $\mathrm{pH}$ level? And by decreasing the $\mathrm{pH}$ level can I clot any type of liquid like milk?

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The clotting that you see is caused by denatured proteins. You can denature proteins physically and chemically. You can use acids or bases (chemical). Also, you can heat it up shake the protein (physical). The $\mathrm{pH}$ of yogurt is different from milk because of fermentation. Fermentation causes production of lactic acid in milk. Which is responsible for the change in $\mathrm{pH}$ (yogurt $\mathrm{pH}$ 4.0 vs milk pH 6.5).