I made homemade heavycream for ice cream the melted butter got hard when poured into the milk

Question

I made homemade heavy cream for ice-cream the melted butter got hard when I poured it Into the milk. Can I melt the butter/milk mixture & see if the butter will soften & blend?

Answer 1

"Homemade heavy cream" is not a feasible idea. It's not entirely impossible, but to make it, you need a machine that will mechanically emulsify the milk with the butter, and there are no such machines for home use on the market.

If you found a recipe that instructs you to pour melted butter into milk, that's entirely wrong, and cannot produce anything than what you described, that is crystalized butterfat in liquid milk - a rather useless product which is almost unsalvageable. I would simply stop trusting any source which makes such recommendations.

For ice cream, you have three options

• if it's a thickened recipe (egg-based custard or a liquid starch pudding) then make your recipe with milk only, and after it's cooled to room temperature, mix in softened butter.
• if it's a pure cream-and-milk recipe (Philadelphia ice cream in Harold McGee's classification), OR includes mixing cold cream into cold fruit puree, you might get away with trying bob1's idea of mixing cold milk with soft unmelted butter in a blender, but in my estimation, you'll also need an emulgator (e.g. xanthan gum) to get it to work. Luckily, this can also improve your ice cream's texture after freezing.
• If your recipe requires you to freeze whipped cream, there are no tricks you can use at home. You have to buy actual whipping cream.

See also How to mix cream to increase its fat percentage?, What are some ways to make whipping cream if I don't have any cream and some of the linked questions in these (many duplicates, some answered).

Answer 2

Short answer - maybe.

Longer answer - Cream isn't just butter and milk (or buttermilk), it is an emulsified suspension of very small fat droplets in liquid. These are so small that they won't combine and form large drops, like larger drops of oils/fats do (put a few drops of oil on top of some water and watch them combine...), without the mechanical agitation you use to make butter (or over-whip cream). They exist as small balls fat molecules that are so tightly joined that their surface tension keeps them separate. When you make butter you break the tiny droplets surface tension, which causes them to join together into larger and larger drops until you get the butter separating from the buttermilk.

The difficulty is re-creating that suspension of tiny droplets. If your milk is cold, the butter hitting it will more or less instantly cool to milk temperature and set solid before you can emulsify it. I think (not having done it myself) that you would need to have the milk at or just slightly above body temperature (cows have a body temp of 37 C/98.6 F, just like us) to keep the butter liquid, and be pouring the butter in while blending as fast as the blender will go. You'd also need the right proportion of milk to butter to get something resembling cream, though I suppose that any cream created would eventually rise to the top, as it does in whole milk. I doubt that whisking would be able to achieve this process.