Thanks, Rotuts.
I'm going with the chefsteps 80C temp. The moscato cream I found at 1 hour was ready, for this pudding I kept a little longer, about 1 hour 10 minutes.
I could clearly see bubbles escaping from the jars when I immersed them in water. I'll check for the seal when I have a chance. the one I opened today didn't have any water, just a little bit of condensation on the top lid.
Do you think if I use the regular canning jar and do a fingertip closing (as suggested on Chefsteps) I can create a vacuum? They say they last a week in the fridge, it would be wonderful for me.
My kids went crazy over the moscato d'asti cream (I'm an Italian mom, they are allowed to try :-))))
And just for record, I'll add a picture also here