Deep frying frozen potatoes takes between 5 to 10 minutes depending on how you like your fries or frozen potatoes to be cooked.
When I deep fry frozen potatoes or deep fry frozen french fries I preheat the oil in the deep fryer while preparing the frozen potatoes or french fries.
Then I place the frozen potatoes or frozen french fries into the deep fryer basket.
When putting the frozen potatoes or frozen french fries into the hot oil make sure to slowly lower the basket of frozen fries or frozen potatoes into the hot oil because putting the frozen potatoes or frozen fries into the hot oil too fast can cause the oil to splash back and cause a fire.
Keep an eye on the frozen potatoes in the deep fryer because sometimes it only takes 4 to 5 minutes to fry the potatoes if you're only frying a little bit of them.
The more potatoes you're frying the longer it takes to cook them.
But it should not take any longer than 10 minutes to deep fry the frozen potatoes.