Is ginger soluble/can it creates strong flavours in water, fat or both together?
No, by strict interpretation of your question, ginger itself is a plant. Plants are typically insoluble as they are composed of chemicals that are fat and water insoluble to a greater or lesser extent.
However, the major spice component in ginger is -gingerol, this is a volatile ketone that is soluble in a range of organic solvents (oils/fats seem likely), but only very barely soluble in water. There are a range of other flavour/scent compounds found in ginger, some of which will be water soluble, some will be organic solvent soluble, that play a role in the taste of ginger, but these are too abundant to go into.
Note that water or fat solubility has only a partial influence on your ability to taste the ginger. You can make tea from ginger and taste and feel very strongly the gingerol, but this is because the gingerol is forming a fine layer of oil on the surface of the water and you can taste minute amounts of it. In addition, it scores 60,000 on the Scoville scale - similar in range to a cayenne pepper and much hotter than a jalapeno, so in a tea with nothing to cushion the effect, the heat is very obvious.
To confirm by experiment: Honey+lemon+ginger in hot water is quite soothing for common cold; the ginger flavour comes out, but a sludge forms in the bottom of the mug. If everything is clean and rinsed, you can actually see the oils come to the surface when you pour water onto dried ginger. The flavour you get from ginger depends on what you do (as well as presence/absence of sugar), so while it's possible to get a strong flavour steeping it in water and straining, it's not the same strong flavour as if you consumed it (not sure if this is just the solubility to mention)– Chris HMar 31, 2021 at 11:09
@ChrisH the change in flavour steeping cf. chewing will be a mix of things. Steeping works best with powder or dried flakes, which will have lost some of the volatiles already, whereas you are more likely to chew fresh, which makes a mush with greater contact with tongue and captures all/most of the volatile compounds in the airway. You could try chewing fresh vs dry and see if the difference is noticeable, but I doubt it will be pleasant. Solvent extraction is the other part of it - water isn't a good solvent for oils, but the fats in your mouth are.– bob1Mar 31, 2021 at 20:03
1the only ginger I'd chew by choice is candied or in syrup. I was meaning more consuming it in a sauce (or soup; I make a split pea and ginger soup that's far better with fresh, using a bit of dried if more is needed towards the end). Anyway, you're right of course– Chris HApr 1, 2021 at 6:15