Persian lime pie – This past Friday was Hyunjin’s birthday, and I had a surprise for her that was in the works for a while. One of her favorite desserts is Key lime pie, and I thought I would try to replicate that for her. I first had this idea a couple of months ago, and thus began my quest for lime pie.
Before I get into the actual making of the pie, a little background is in order. For starters, what exactly is Key lime pie? I had had it before, of course, but I didn’t know how it was made or even why it was called “Key lime pie.” I had assumed that the name came from the Florida Keys, and that it was a pie native to that region. This is not entirely incorrect, but in fact it is the limes that take their name from the Florida Keys, and the pie that then takes its name from the limes. Key limes are smaller and more tart than ordinary limes (known as “Persian limes”). They are also yellow, while Persian limes are green.
I knew from the start that it was going to be nigh impossible to find Key limes in Korea—finding Persian limes was hard enough. After I first got the idea, every time we went to a department store I would surreptitiously scout out the grocery sections, but I never saw any. I even asked the people working there if they ever had limes, and no one I talked to said that they did.
I did find a few sources online that sold limes, but most of these were frozen and rather expensive. Then, on a trip to Itaewon to meet Gord for dinner and drinks, I checked out some of the small groceries there that sold imported goods. The first few places I checked didn’t have any, but then I happened to spy some in a plastic bag tucked away in the refrigerated section of one small shop. They were 2,000 won a piece, which struck me as a bit pricy, but beggars can’t be choosers. As it turned out, the next shop I tried had them as well, at the same price. The owner of the first shop told me that the hotels would come in and buy up all the limes, so there was no guarantee that they would always be in stock. I was back in Itaewon last Wednesday, though, and fortunately I was able to pick up a bunch.
Next, I needed to find the crust ingredients. I decided to forgo my usual pastry crust and try out a graham cracker crust, as is typical for a Key lime pie. Unfortunately, I could not remember ever having seen graham crackers in Korea (thinking back on it now, though, I probably should have tried the markets in Namdaemun). What we do have plenty of here, though, are Digestive biscuits. I had developed a taste for these when I was in London—being a poor student, some tea and Digestive biscuits were the entirety of my typical afternoon tea. They sell these in most large marts, but I decided to get a bulk-size package of six boxes on a recent trip to Costco. Hyunjin knows of my love for these tasty treats, so she didn’t suspect a thing.
The last ingredient I normally wouldn’t have at home was condensed milk, and I was able to pick up some at the E-mart down the street. Oh, and I also picked up a small container of whipping cream there as well, for the topping. Now, on to the show.
These are the Digestive biscuits, waiting to be mercilessly crushed. The recipe I was following called for 16 graham crackers. I had no idea how much that would come out to in terms of weight, but I do have the internet, and not only can you be sure that someone out there knows the answer to your question, but someone else has probably already asked that question before. I don’t remember how much an individual graham cracker weighs, but I do remember that 16 graham crackers comes out to about 225 grams. I put a bowl on the scale and started piling Digestive biscuits in it until I got to close to that amount. It doesn’t look like it, but I think there are around 18 Digestive biscuits in that photo above, and they came out to around 215 grams or so.
Here are those same Digestive biscuits, now just a pile of crumbs. The crumbs may look fairly uniform here, but they aren’t. Rather than take out the food processor that Kevin graciously left with me before he went back to the States, I decided to crush the biscuits by hand (actually, I used a pestle, but it was still hand-powered). As a result, I was left with some larger chunks that somehow missed their date with destiny.
Here you should be able to see the chunks more clearly. This is the remains of the Digestive biscuits mixed with 100 grams of butter. The recipe called for around 110 grams, but I happen to know that Digestive biscuits have a much richer taste than graham crackers (that is, they have more fat, or at least they taste like it), so I reduced the amount of butter a bit. It was only later that I read the comments on the recipe and saw that one commenter actually added butter to make the mixture more workable. This was after the crust was already in the oven, so it was too late to do anything about, but it did worry me some.
I pressed the mixture into the pie plate and ended up with this. The crumbs are even more visible now, and I was concerned that they would compromise the integrity of the crust. Once again, though, it was too late to do much about it, so I put the crust in the oven for ten minutes at 180 degrees Celsius and hoped for the best.
With the crust in the oven, it was time to deal with the limes. The recipe was for Key lime pie and originally called for a half cup of juice, or the juice of approximately a dozen Key limes. But there was a note at the bottom that said Persian lime juice could be substituted, and that only four to six limes would be needed. Well, I didn’t want to be short, so when I bought my limes in Itaewon I bought eight.
This is the first lime, zested (apparently “zest” is not a verb in this sense... but it should be) and cut in half. By this point the kitchen was filled with the wonderful fragrance of limes, and I realized that I had forgotten what they smelled like. I am used to working with lemons, and I love their fragrance, but limes are an entirely different experience. It’s hard to describe—the best I can come up with is that limes are “brighter.”
This is what the limes looked like when I was finished with them—two teaspoons of zest on the left and a half cup of juice on the right. After juicing the first lime, I was surprised to find that I had a quarter cup of juice, and I ended up having to use only two limes. I had thought that, if anything, the limes here would be smaller than in the States, but I guess they’re bigger. Either that, or the author of the recipe was way off in his calculations. Still, I could think of worse things than having extra limes lying around the house (we used one with dinner last night, adding the juice of one lime to some roasted vegetables that we had over penne—it was delicious).
When I was finished with the limes, it was time to take the crust out of the oven. As you can see, the top edge was a bit rough with some thin cracks, and the crust bubbled up in places, but all in all it seemed to be holding together pretty well. I’ve never actually made a graham cracker (or Digestive biscuit) crust before, so I was a bit nervous about how it would come out. In the end, though, it served its purpose.
With the crust cooling on the rack, I prepared the filling. The first ingredient was the yolks of four large or extra large eggs. Usually I don’t pay too much attention to egg sizes in recipes, but I decided to see if the eggs I had bought were large or extra large by American standards. After another internet search and some calculations, I figured out that small eggs weigh 43 grams, medium eggs weigh 50 grams, large eggs weigh 57 grams, and extra large eggs weigh 64 grams. I took an egg from the refrigerator and put it on the scale to find that it weighed 73 grams. I guess that would make it jumbo or something. Good enough for my purposes at any rate. What you see above is the gruesome remains of four of those jumbo egg yolks.
Next up was the condensed milk, which forms the largest part of the filling. The recipe I was following called for 14 ounces. One of the (many) things that annoy me about Imperial units is the fact that ounces can be a measure of both volume and weight. All the other units in the recipe were volume, though, so I used liquid ounces in my calculations. There was no way I was going to pour condensed milk into a measuring cup and then pour it back out again, so I wanted to convert to grams. Condensed milk is, of course, more dense than regular milk, but I could not find a consistent figure for density and ultimately decided to ignore it. I threw my careful calculations out the window and guesstimated 400 grams. It probably came out to a little less than 14 (liquid) ounces, but I figured it would be close enough.
I took this one quick shot in the middle of the mixing process. After blending the yolks and condensed milk, I added half of the lime juice and mixed it until it was blended. Then I dumped in the zest before adding the remainder of the lime juice and mixing that. The mixture that resulted was then poured into the waiting crust.
This is the pie after baking for another ten minutes. Traditionally, Key lime pies are not baked—the lime juice sours the condensed milk to the consistency of a thick custard—but the recipe recommended baking it for ten minutes to kill any salmonella bacteria. Baking also makes the pie even thicker, which isn’t a bad thing.
At last, the results. On top is fresh whipped cream with just a touch of sugar and vanilla extract. I know that some Key lime pies have thick meringue toppings, but not only would that have made the process more complicated, I wasn’t interested in hiding the flavor of the pie. Whipped cream is another traditional topping, and I thought a dollop would be a nice complement to the pie.
This photo was taken on Thursday, the day that I baked the pie. I had intended to save the pie for Hyunjin’s birthday on Friday, but she discovered a few incriminating receipts lying around the house and grew curious, so I decided there was no real reason to wait. Looking at that photo now, I have to say that it is a rather poor substitute for the pie itself. It has been so long since I’ve had an actual Key lime pie that I don’t remember exactly what it is supposed to taste like, but I can say that this Persian lime pie tasted very good.
The power was out in our apartment on Saturday, so we went down to visit Hyunjin’s parents, bringing along the remainder of the pie and whipped cream. Hyunjin’s mother liked it so much that she asked me to bake two of them for Chuseok. I was going to bake pies then anyway, but they were going to be blueberry. Looks like it will be lime pie this time around, though.
When it does come time to make those Chuseok pies, I am going to work on improving the crust. For one, I will definitely be pulverizing the Digestive biscuits in the food processor to make sure they are uniformly crushed. I will try to make the crust a more uniform thickness, as the “heel” of the pie came out much thicker then the rest of the crust. I will also not push the crust up so high, as the filling doesn’t go all the way to the top (possibly because I didn’t use exactly 14 liquid ounces, but the flavor came out just right and I don’t want to mess with the proportions). Finally, I’ll probably use a trick I’ve used with pre-baked pastry crusts to prevent bubbling: line the crust with wax paper and then fill it with rice for the first half of the baking time. I even have a container of rice lying around for just this purpose.
All in all, though, I was very pleased with the way the pie turned out. Having never made a lime pie or a graham cracker/Digestive biscuit crust before, I was slightly apprehensive, but it turned out to be a fairly easy process, and the results were very tasty. Some day I would like to try this with actual Key limes, but for now I think I can make do with Persian limes. (If you happen to be in Seoul and want to get your hands on some limes, drop me a line and I’ll give you directions to the shops in Itaewon.)