I have learned something from Google Books. The above table shows that celery oleoresin comes in three grades. Yet the usage is roughly equal. My hunch is to by a middle grade. As this is the resin, it is extracted without other oils within the seed. I guess that makes it purer. It would be soluble in alcohol. That will add another ingredient to my already long list (28) of ingredients, bringing the total to 29. I will probably cut the resin in vodka, add it at the start of the tomato sauce cooking. The alcohol will boil off, leaving the celery flavor.
by Gary Reineccius
That is from:
Food flavorings By P. R. Ashurs