How would you totally eradicate a winter infestation of fruit flies in kitchen?

[Marthe48]

13. The vinegar works

or stale beer, or sweet pickle juice. Putting some bleach down your drain will help if they are drain flies. Rinsing your dishes will eliminate a food source.
I wash all of the fruits and vegetables I bring home, because even if you don't see the flies, there might be eggs on the produce and they hatch fast. If I see fruit flies in the produce section of a store, I buy produce somewhere else.
If I wash bananas, I lightly dry them, and put them in a rack to air dry a little more. Then I store them in the microwave or oven.
A last resort would be to put the wand on your vacuum and vacuum up as many as you can. My daughter gets cluster flies in the fall, and we all are pretty good at reducing the population in the house.

There are some things I don't like in the house and flies of any kind are No. 1 on the list.

Hope some of the advice helps.