What are the conditions that raw milk, just milked from a cow, should stand to obainin thick traditional Romanian smântână? Let's say I have fresh, raw, unpasteurized milk, just obtained from a local cow owner who milked the cow within the last hour, the milk is still slightly warm from the cow's body heat. In what conditions it should stand and for how long, to obtain thick, traditional Romanian smântână, viscous to the point that it would not flow out of a cup when its turned over.
I know such smântână is sold by old ladies on the farmers markets in Romania. What to do if my smântână doesn't turn out like that, even having the same milk, from the same cow, bought from them, not skimmed. For the educational purpose of the question let's assume they are not cheating me and selling me milk with some cream already skimmed, that can be a factor, but let's eliminate all other possible factors before accusing the cow lady.
Traditional Romanian smântână differs from traditional French thick high-fat crème fraîche. Creme fraîche is made from pasteurized cream and has a bacterial starter culture added, while smântână had no pasteurization done at any point and no cultures are added, only the milk's natural bacteria are making it. This process is without the use of a centrifuge or separator, as separator-made smântână is much more liquid.
I am not sure if smântână is considered a cultured product or not, as while it is said it should not be sour, but it certainly ferments a little while standing, only not as much as soured milk or yogurt? The Wikipedia page mentions &quot;Smântână taste is tangy and sweet, a soured smântână is considered as spoiled.&quot;
I am looking for information on the parameters to obtaining a thick, highly viscous, non-flowing smântână, for example:

The temperature at which to keep the milk
The time to keep it at that temperature from the moment of milking the cow till smântână is ready
Anything else I should know to ensure I obtain a thick, highly viscous cream which doesn't taste sour

The correct answer will be only one which refers specifically to the Romanian traditional way, ideally from someone with knowledge from a Romanian grandmother, or otherwise having knowledge how it was traditionally done, before there were fridges and separators. Any other ways to obtain cream, any procedure not specifically from Romanian tradition, is outside the scope of this question.
I can't give you the Romanian recipe but I doubt it differs much from Polish.
First, Start with cow milk. It must be genuine unprocessed milk - absolutely not cooked, UHT, preserved, skim, lactose-free or other 'inventions' where the natural bacterial flora has been killed and the milk will rot instead of souring.
Make the standard fresh cream. There were traditional tools for that but a centrifugal separator will do just fine, with far less effort; the technology doesn't 'spoil' this part.
Don't go over the top with fat content. The American creams are ludicrously fatty. 14-18% of fat content is normal, up to 30% is okay but really unnecessary and will make it harder to achieve the right results.
Then put the sweet cream in a clean ceramic jar, cover with a clean cloth that allows air through but will stop insects, and leave in a slightly cool place - temperature of order of 18 Celsius degrees (although 'cooler side' of room temperature is fine). Let it sit overnight and if you started with genuine unprocessed cow milk, it will sour and thicken into the traditional sour cream with a layer of transparent whey on the bottom.