@Slevin if you are looking for very high quality accurate flavors... have a look at the
Medicine Flower line of water soluble flavors.
You want to look at the MF Premium Flavor Line and the Silver Flavor Line. You do not want the Gold Flavor Line (oil based).
MF flavors are organic, no sugars or calories, and are wheat- and gluten-free. They are cold-processed using extraction without the use of any colorants, fillers, diluting agents or preservatives.
They are obtained through a proprietary technology conducted at temps below 118 degrees F. The process comprises a multi-stage extraction encompassing initial desiccation, lyophilization, CO2 and HFC extraction.
Medicine Flower flavors are derived from the actual flavor on the bottle (ex: banana is CO2 extracted). 100% genuine flavor extracts.
They are not cheap compared to other flavors. However a bottle of MF flavoring will last a good long time because you are not using as much as you would with any of the other flavors commonly used in DIY.
Their flavors are super ultra concentrated. Meaning you only need to use a tiny amount for bold flavor. In a 30ml mix it is normal to use 1-3 drops (all depends on which flavor).
Generally... a few drops of a MF flavor equals up to a teaspoon of others. That's 30-70 times higher potency versus the majority of other flavors.
MF flavors are very accurate tasting. Example: MF strawberry tastes like a freshly picked California strawberry.
There are a few of us using MF flavors for DIY.
Good luck in your flavor(s) search.