My ricotta didn't curdle ?

Followed the recipe EXACTLY but I am left with a pot of mostly liquid with TINY almost grain like curds (?) through it. Is this how it should be ? It has been standing for 45 mins now. Should I heat it up again or is it a failure ? Any useful advice would be appreciated, thanks.

Without seeing the recipe it is hard to help, but it could be that the temperature was not high enough. Were you using whey or milk? The basics are:

Heat to 90 degrees C, stirring often. Remove from heat. Add white wine vinegar (about 2 tab per 2 litres of milk or 1 tab per 2 litres of whey), stir very briefly to combine. It should coagulate immediately and form white curds floating in a clear lemon coloured liquid. Leave to cool undisturbed 30 min to a few hours. Scoop the curds off the top and drain in muslin or a ricotta basket. Drain 20 minutes. Use immediately or store in the fridge up to a week.

If the curds do not form immediately add little more vinegar.

If you want more specific advice let us have the recipe you have followed.

Use whole unhomogenised milk (not low fat or otherwise processed)

I used 3 cups milk (blue top) and 1 cup cream. Heated til boiling, then added 1/4 cup lemon juice and simmered for 3 mins. Switched off and left for about an hour. Then wondered what to do next and posted on message board ! Since then, I decided to strain what there was in the saucepan, covered it up and went shopping. I have just come back and see about 1 generous cupful of ricotta in the muslin cloth. It's actually yummy ! What do you do with all the liquid which has strained off ? Thanks for your help.

I dilute the liquid and sprinkle it on acid-loving plants in the garden. It has a lot of nutrients but is acidic so you need to choose where you put it.