Puree versus juice

Beer Recipes
1

I have the local brewery’s high level recipe for a summer grapefruit wheat beer.  After fermentation, they add 55 gal of grapefruit puree to a 120 barrel batch.

If I did the math right, that is 1.95 ounces of puree per gallon?

Can anyone weigh in on the adjustment  I might need to make, if I wanted to do a small trial batch with grapefruit juice instead of puree?

My plan was to pull some samples and work it out, but I was debating puree vs juice.  How different would puree be versus juice?

The plan is to cold crash and add the grapefruit.  Keg and keep cold to avoid any further fermentation.  (The brewery won’t fill a growler and I believe their kegs are unpasteurized).

Thanks for your thoughts–

2

I would find one of the fruit purees used by brewers, like Oregon fruit, and see what the sugar content of the puree is and convert that to gravity. Then do the same for the juice and scale the juice volume up or down. It may not be a perfect match on flavor but probably a good starting point.