I make a three-ingredient ice cream (heavy whipping cream, sweetened condensed milk, and flavor oil, no ice cream maker required). The stuff is absolutely awesome but rather pricey to make, something along the lines of $5 a quart. Since the cream is the most expensive component, I’m always on the prowl for not-quite-expired marked-down cartons of the stuff. Awhile back, the local salvage grocery had several quarts at some insanely cheap price, the catch being that it was frozen. I couldn’t take the chance that it would still be there later, so instead of buying one to try out, I bought a bunch.
Okay. Turns out heavy whipping cream, once frozen, does not unfreeze well. I thawed it in the refrigerator, it came out clumpy, I poured it into the mixing bowl and turned on the mixer at fling-everything-around speed. I learned flying clumps of whipping cream must be treated as grease stains or they won’t wash out of your shirt. It never really whipped up. It sort of reached the consistency of, well, thick milk. I decided to use it anyway, and added the other ingredients. Turns out thawed, semi-whipped heavy whipping cream does not freeze well. Basically I ended up with ice cream containing clumps of frozen butter. Further experiments have yielded the same results.
Is there some sort of trick to this, something that everyone else knows but I somehow missed? I considered straining out the clumps, but I’m thinking that would remove too much of the fat content and it would just end up like the time I tried to whip half-and half. (It didn’t work.) And if it’s not going to work for ice cream, is there something else I could do with it? I mean, besides making butter. I accidentally did that once, too. I don’t need that much butter.
Have you tried straining it and using only part of the liquid?
No, I haven’t. I’m guessing that the clumps are butterfat, and taking them out would pretty much ruin the point of cream. My understanding is that the fat is necessary to get it to whip up.
Sorry, I missed the edit window. What I need, I think, is a way to reincorporate the clumps into the liquid. I’ve got beyond the “whipping cream” setting on my mixer into the “egg white” setting, and it still isn’t happening. It just flings more stuff around the kitchen.
Ah, so it is hopeless, as I feared. Still useful for sauces, but I am not a sauces person.
What I meant was, keeping the butterfat but recombining it with only part of the liquid you strain off. I would guess the less liquid you have, the thicker the cream will be.
Or, after reading the article, maybe not. 
But I’d guess it’s worth a try.
Hey, Magicicada, mind posting your recipe? I’d love to try it .
I can’t take credit for it, but here it is:
2 cups heavy whipping cream
1 standard can of sweetened condensed milk
Flavoring of some kind*
Whip up the cream in the usual fashion
In a separate bowl, stir together the sweetened condensed milk and the flavoring, then fold that mixture into the whipped cream, trying not to deflate it
Pour into a freezer safe container, and freeze
*I use Lorann hard candy flavoring oils, which you can get from Amazon or in country-type stores. They come in this little glass bottles, and I use the whole thing for each batch, although some of the more spice-oriented ones are kind of strong.
My biggest successes have been bubblegum (if you’re into bubblegum ice cream), wintergreen, cinnamon (although you have to love cinnamon for it to work for you), and, in a burst of inspiration when I found caramel sweetened condensed milk and added green apple flavoring, candy apple.