Key Lime Pie

Someone asked me this week if I would try a Key Lime Pie for them, and as I am always up for a challenge I was more than happy to give it a try. I wondered however what a Key Lime was and why it would be so different to a normal like.

Key Limes are found in Florida and are much smaller than regular limes. They have thinner rinds, less seeds, a much much higher acidity and a sweeter flavour, which is why they are preferred for particular recipes like marinades for fish and meat.

Key Lime Pie is a very traditional recipe which dates back to the 1850's in the Florida Keys area. Before biscuits were used for the base, a pastry crust was made.

I started by crushing the biscuits which I put in a paper bag and bashed with my fist like there was no tomorrow, good stress relief, but I think a plastic bag would have been better as I ended up ripping a few paper bags in my quest for small biscuit crumbs.

The next task, after mixing the crumbs with butter was to press it into the base of a pan AND up the sides. Attempt 1 = fail. I put the crumbs back in the bowl and added double the amount of butter to really get the mixture moist so it would stick and it worked. Attempt 2 = success (although not perfect). Then due to force of habit I put it in my preheated oven until about 30 seconds later I realized I was supposed to put it in the fridge to cool for 15 once I prepared the filling then bake it all at once. No harm done though, as I took it out straight away.

The filling was quite simple, and at first taste I felt it lacked the real kick that limes have, so I added the zest of 2 more limes. I think one of the most important ingredients of this recipe is the whisked egg whites which you fold into the mixture as it gives such heavy ingredients (egg yolks and condensed milk) suck a lightness and makes this pie nice and fluffy when baked.

My base was ready so I filled it and baked. When I took it out of the oven I was quite eager to see what it was like once I took it out of the tin. I let it cool for about half an hour then attempted to take it out. I could see that it was still soft but I underestimated how much. Once I took lifted it out I pretty much put it back in straight away and left it in the fridge to set.

I went to inspect it this morning and it was harder and in a much better state. I lifted it out again and it was nice and square like it was meant to be (well for the fact I used a square tin as all of our round ones had gone walkabouts, especially the spring form one). The result was a nice and fluffy cake with a beautiful base. I have always loved the biscuit base many cheesecakes use but have never tried it, so now I know how easy it is.

The pie is generally garnished with extra whipped cream, but I thought it is not necessary as it is not a overly rich cake which needs something like ice cream or cream to balance the flavours.

Key Lime Pie

Preparation time: 25 mins
Cooking time: 25 mins
Cooling time: 4 hours

Ingredients

250g wheatmeal biscuits
200g butter
5 egg yolks
400ml (1 can) condensed milk -- please don;t use skim version as it just as extra sugar to compensate for lack of fat
zest of 3 limes
200mL lime juice (about 5 limes worth)
3 egg whites

Method

1. Preheat oven to 160 degrees.
2. Crush biscuits and mix with melted butter.
3. Grease either a spring form tin, or line a non-spring form tin with baking paper (so it is easy to take out)
4. Press crumbs onto tin base and up the sides then refrigerate for 15 minutes.
5. Beat egg yolks until light and smooth. Add condensed milk slowly and mix until combined.
6. Zest the limes BEFORE you juice them then add both into the egg mixture.
7. In a separate bowl, beat egg whites until hard peaks form then fold into lime mixture.
8. Pour onto base and then bake for 25 minutes or until the top of the filling sets (the filling will still be soft on the inside but it will set further while it cools.
9. Once slightly cool, refrigerate overnight or at least for 4 hours.
10. Serve with slices of lime on top and IF you want, add fresh cream.