DEBOLINA ROY
Take a little bit of the liquid and rub it between your thumb and index finger. Milk will feel how much creamier and more sticky. Synthetic milk can often feel very soapy or oily for additives like detergents and chemicals.
Upon boiling on medium heat real milk should remain white in colour, or only develop a very slight cream colour. But synthetic milk will have a noticeably yellowish colour due to its urea content.
Drop the milk onto clean, flat surface at a 45-degree angle. Real milk will have a slower flow leaving a white trail or pattern. Fake milk will flow quickly and not producing any white trail.
Take a small sip and notice the aftertaste. Natural milk has a soft, nice-sweetness, while synthetic milk often can have an unpleasant, sour, or chemical flavour that stays with you for some time.