How to reduce marinade to a sauce?
I know that this is a common method to make a sauce from a marinade but I haven't done it much so wanted some tips. Usually my Friday night consists of seafood marinated in an Asian-style marinade with green onions, garlic, rice vinegar, soy sauce, sesame oil and ginger. Usually I just add a little water and pour the marinade over the finished fish, but last week decided to try out the simmer method to make a sauce. I simmered on low and the smell of evaporating vinegar was quite strong and it seemed to boil very readily even though on very low heat and I backed away in fear. Should I just continue to simmer/boil to reduce the water? Any issues with vinegar in the marinade? If it includes a high sodium ingredient like soy sauce should I worry that it will become too salty when reduce?
reducing anything just boils out the water, so it concentrates more heavily the more you reduce it..
lots of strong flavors with the vinegar and the soy, so you'll have to test it out as you go.
That is typically done with wine based marinades. Marinades that have lots of oil or ingredients that are salty cannot be used in the same way.
Uh, you do HEAT that marinade to at least a low boil for several minutes before pouring it over the "finished fish" don't you?? It's rather risky/unhealthy to simply pour leftover raw marinade as is over finished food.
As far as turning your marinade into a sauce, you can simply reduce it, tasting it for concentration (AFTER it has reached a low boil for a minute or two at least), or you can bring it to a boil & add a cornstarch/liquid slurry to thicken it slightly.
If you are happy with the taste but want a thicker sauce, bring to boil, reduce to simmer, add a mixture of cornstarch and water.
Making chicken teriyaki on the weber, I often boil the used teriyaki marinade until it coats a spoon and use it as a glaze.