I just tried it out nectar making a bit ago. The highest quality recipe I've seen is a "Great Tasting" one, not sure if it can go higher. I got this at Skill Level 2 on my third batch after two terribad ones so I think it's independent of skills... hmmm, if memory serves me correctly, I think it was something like 3 Pomelo, 3 Plum, 4 Apple, I ended up naming it "Ether Mist" as my two earlier batches had such colorful names as "Applegeddon" and "I Fail At Nectar Making".
There is a challenge that gives you the ability to tell a recipe's outcome before making the Nectar, but I haven't achieved it yet, but it should help tremendously.
Errr... Scratch that recipe, I got it wrong . Turn out there's a rank that's even higher "Absolutely Amazing" which is very rare. I only know of one combination that yields it, 5 Apples + 5 Renoit Grapes, but since the ingredients are cheap, it doesn't yield much total profit. Trying to find an amazing combo that involves Life Fruit and Flame Fruit, but no luck yet.
Oh yeah, that ability I mentioned? Not that useful, it'll tell you what combinations are horrible, but it's pretty hit or miss when it gives a positive estimate and the result can still turn out bad.
The best "Absolutely Amazing" combo I've seen is 5 Life Fruit with 5 Cranerlet Nuala Grapes. With a sim who has all the available skill bonuses, using all perfect fruit and an upgraded machine, this stuff rolls off the line at $532 per bottle. I have some that's been aging in a rack in my cellar for a just a few weeks (I think), and it's up to $2500 per bottle!
PSN: xamdam, Level: Xamdam's Caverns, Location: On point near North Pole, Icon: Red X http://www.youtube.com/watch?v=2vi0Ke4cbNk
Awesome! Thank you for the recipe! ^_^ That's probably one of the best, if not THE best nectar recipe in the game given the ingredients.
It doesn't seem possible to make an absolutely amazing Life Fruit + Flame Fruit combo since the two fruit don't naturally mix well together, but the Flame Fruit bonus is so small compared to the Life Fruit one and that it's not even really worth bothering with and better for mass production than for selling anyway.