You may be able to overcome some of the "eggy" flavor by adding extra grapefruit zest to the finished curd.

Thanks! I will try that next time.

I typically use Rose Levy Beranbaum's recipe from the Cake Bible. It makes a tart and very lemony curd. You could also use Alton Brown's recipe, which uses more sugar and butter. http://www.foodnetwork.com/recipes/alton-brown/lemon-curd-recipe/index.html

Lemon Curd (makes 1 cup)

Ingredients:
4 large egg yolks
½ cup plus 2 T sugar (4.5 oz)
3 fluid oz lemon juice (about 2 & ½ large lemons)
4 T unsalted butter, softened
pinch of salt
2 tsp finely shredded lemon zest

In a heavy nonreactive saucepan beat the yolks and sugar until well blended. Stir in the remaining ingredients except the lemon zest. Cook over medium-low heat, stirring constantly, until thickened and resembling a thin hollandaise sauce, which thickly coats a wooden spoon but is still liquid enough to pour. The mixture will change from translucent to opaque and begin to take on a yellow color on the back of a wooden spoon. It must not be allowed to boil or it will curdle. Whenever steam appears, remove briefly from heat, stirring constantly, to keep from boiling. When the curd has thickened, pour at once into a strainer. Press with the back of a spoon until only coarse residue remains. Discard the residue. Stir in the lemon zest and cool. Pour into an airtight container. The curd will continue to thicken while resting and cooling.

Can you share your yolk-only recipe?

Interesting. I guess I will blame the egg whites in that case, and if it only got to 172° you didn't overcook it & it shouldn't have curdled. The egg white is where the eggy flavor is, when I make bread pudding or french toast I typically use all yolks so it doesn't taste of scrambled eggs. I've not made grapefruit curd, but have done lemon many times and only use yolks.

It called for the same amount of egg yolks and whole eggs (6 of each). Since it was a big batch, I dont want it to go to waste, though it might have to. I was cooking it with a probe thermometer, didnt get above 172.

I'm curious, did your recipe call for whole eggs or just egg yolks? I presume the eggy taste is from overcooking the eggs (they got to be over 180°F and "scrambled"). I don't know if it's solvable, but you could experiment with a small portion of it and try adding the fresh grapefruit juice you have.

Its not that the consistency is bad, its the taste! I do have more grapefruit juice if needed.

A little grapefruit extract as well may cover the eggy taste!

The only way you may be able to salvage it if you have a hand blender like a emmersion blender to smooth it out or sometimes a drink blender will do the same thing or a food processor it will make it smooth again and then refridgerate it so the butter can solidify again. Good luck!