I think I grated about 1/8 of one into a gallon and it was completely lost.
For my Pear Nutmeg I didn't grate, I just smashed it roughly a couple of times. Crushed made it easier to remove for me. Ofcourse, that may be why it was a little overpowering with a 5 gal batch and 13 pounds of pears, pureed, frozen, thawed, pectic enzyimes and run through a screen after blending again. And the pear was in the forefront in the first 6 months after aging then the nutmeg came to the fore with a vengence. I like nutmeg so it wasn't a big deal. Just lost most of the yummy pear flavor.
Also, used a whole nutmeg in a pumpkin spice mead and the nutmeg and cinnamon (4 sticks about 2 inches) dominated the pumpkin and made it cry for mercy.
So based on that, 1/2 or 1/4 for subtle of freashly crushed nutmeg in a 5-6 gal batch for me is plenty good enough.
I have also found that for a good vanilla, I need more than 6 beans in the secondary. I think that the next time I do a vanilla I will do 10 or 12 beans, split and scraped into a muslin bag in the secondary.
Jury still out on almonds. Also, I made some hazlenut extract from 1 cup of chopped and toasted hazelnut that I am planing on in a Pumpkin Hazelnut. I may just get another cup and make more for the batch, I don't think that I extracted enough out of the chopped, toasted hazelnut.
I plan on experimenting with some nut flavors and mixing it into my mead from homemade extract rather than the nuts in the mead. Should be better and take less of the nut to do. I noticed not many people use nuts in their mead. Mostly the excuse is that the different nuts are too oily. Hmm.
That's what I got going on a little.
Spices are a bit hard to judge for me.
Matrix