Homebrewers - Whats in the fermenter?

Ah, I guess I didn't realise that Rose's lime juice was a syrup, I was assuming it was juice. Shows how many mixed drinks I make, I guess.

The english word you're looking for is "zest". That's what landhoney originally talked about using.

Beer finishing in the high 3s pH isn't uncommon, but my point is that it would take a whole lot of zest to get enough citric acid to make the wort too acidic for the yeast.

Being that he's talking about an India Pale Ale, one can safely assume he's talking about an ale yeast, or top fermenting. With the citricy hops, it'll be more american style, so the default choice would be Fermentis US-05/Wyeast 1056/White WLP001. It's a relatively clean, neutral yeast.