Why I can't home made whipped cream by adding milk and butter

I want to make heavy cream at home for whipping because market cream contains too many chemicals.

So I take 1/4 cup homemade butter (which is made from 7-day malai) and 1/4 cup full-fat milk

I put the milk on the stove and add the butter at the same time. When the butter melts, I turn off the flame and pour the mixture into the mixer and run the mixer for 1 minute

I get a mixture. I pour this mixture into a bowl and cover it with cling film

The next day, I beat this mixture with an electric beater, but within 1 minute, the milk and butter separated

Questions are:

• What mistake did I make?
• What ratio should I use for perfect whipped cream?
• Is there any other method to make whipped/heavy cream?

You can’t make whipped cream from butter. The butter in milk and cream is in microscopic globules which are really good at remaining mixed in, and which stabilize and thicken the foam when you whip the cream. Butter, in contrast, has the fat from those globules combined into a solid mass, which will not readily stay in suspension.

The way to make whipped cream is to take fresh cream and whip it. Butter is not useful here.

You may be thinking of buttercream frosting. This is not whipped cream, but it is made from butter and usable as a cake topping. For buttercream, you’ll use a ratio of about two parts powdered sugar to one part room temperature butter, and possibly a small amount of milk if needed, whipped together. (If you use malai instead of kneaded/rinsed butter, you will not need any milk, and you may need to add more powdered sugar to get a nice, firm consistency.)