It's not an r sound like in American English, it's a flap. It sounds like a soft 'd' sound. In this particular sentence I find it easier to hear in 'gutter' than in 'jenter'. The 'a' in 'jenta' should sound like the 'u' sound in 'cup'.
In practice you can often tell from context which word it should be - it's a little harder in an isolated phrase like this