How to thicken a sour cream recipe? Sour cream is not sold in stores where I live. I found a sour cream recipe. This asked me to put some cream in a bowl, add white vinegar, then let it sit in the refrigerator for one hour. I used some cream called “UHT thickened cream” and added some drops of white rice vinegar.

The taste is okay, but it is liquid like milk and not thick like the sour cream sold in stores in the United States. How can I thicken this sour cream?
You need more vinegar for it to thicken.  I make salad dressing with cream as the oil and when I stir in the vinegar, it becomes quite thick.  Unfortunately, it will probably have a strong vinegar taste in your recipe (which turns out to be okay in a salad dressing).