No matter where you look, there’s a good chance you’ll find some surprising science hidden in a seemingly not at all sciency food dish. Same for these Trini kurma, a cookie covered in ginger sugar syrup. Apart from it being delicious (in the ‘can’t stop eating!’ sense), it contains some short crust pastry science and uses some special features of sugar.
What is Trini kurma
Trini kurma comes from Trinidad & Tobago. The kurma is commonly made for special occasions such as Diwali, religious ceremonies or festivities in general. But it definitely isn’t just a special occasion snack, you can also find it in plenty of stores as a great treat.
Kurma consists of two main components: a deep fried cookie and a sugar coating on the outside. The cookie itself is not sweet at all but contains several spices for flavour. The sugar syrup contains a decent amount of ginger, giving it a great depth of flavour!
Trini kurma is one of those dishes that most people learn simply by seeing how it is made over and over again. Not living in Trinidad though, that’s a bit more complicated, but luckily, the internet can teach us a lot nowadays!
Note, in Guyana they seem to have a very similar cookie, however, they call it mithai!
Kurma cookie science
As you can see on the photo above, an important characteristic of a kurma cookie are the flaky layers within. These give the cookie a great crunch without become hard like a rock. In order to create these layers you have to start making the cookie by rubbing in butter & shortening into flour. It’s a process that is very similar to that of short crust pastry!
Only after you’ve rubbed in the fats will you add the water. As a result, your dough will still contain some lighter and darker spots, which is perfectly fine. Some of the smaller lighter spots are the fat that has been incorporated into the dough. These little pieces of fat play a crucial role to create the flaky texture.
Kurma cookies aren’t baked in the oven, instead, they are deep fried in oil.. As soon as the dough hits the oil you will see that it starts to expand. This is moisture within the cookie that immediately changes into steam when that cookie hits the oil. The starch and proteins in the flour will cook as well, setting their structure. Also the butter and shortening will melt. As a result, all those places that previously contained the fats are now empty and you’re left with a flaky texture. (This is actually very similar to what happens when making puff pastry or even croissants!)
When you’re frying kurma, or any other food for that matter (especially french fries) you try to achieve two things:
- Fully cook the inside of the cookie: you don’t want any raw dough left in the center. Even though these cookies are thin, it takes a while for them to fully cook through. This is why it’s best to start frying them at a moderate heat.
- Brown the outside: the final cookies should be a nice light brown. This browning happens faster and faster at higher temperatures. You don’t want to burn your cookies either though.
Once the cookies come out of the fryer they will be super crispy and crunchy. The heat has not just achieved those two goals above but it also evaporates moisture, which makes them even crunchier! These cookies stay crispy for really long, as long as they are protected from humidity (best to pack them in an air tight container).
Ginger sugar layer
The cookies are great, however, makes really makes theses cookies shine is the ginger sugar layer that surrounds them. The ginger and sugar lift the cookie up and make it almost impossible to resist eating more. You make this sugary crunchy layer on the outside by cooking up a sugar syrup and pouring that over the cookie.
When cooking this syrup it is very important to cook it to the right consistency. You want to have the right amount of moisture left in the syrup. Here is where we’ll need to bring in some science.
Sugar dissolves in water. As you have probably seen in several instances (e.g. adding sugar to tea or coffee) more sugar dissolves in water if it is warmer. If you want to create a very concentrated sugar solution you will have to boil the sugar + water to a temperature well above the boiling point of water (100°C / 212°F). By boiling the sugar solution, you evaporate more and more moisture, making the solution even hotter. Because of this, the boiling point of your sugar solution is directly linked to the concentration of the sugar solution. In other words, if you are looking for a specific sugar concentration, you just have to measure the temperature of the solution during boiling and you will have it.
So why is this important for kurma?! Well, a sugar solution can roughly do three things when it cools down. One, it can form a hard and brittle glass-like structure. This is what lollipops or brittles are for instance. This happens only when the sugar concentration is very high (thus at very high boiling points). It can also just form a syrup, be liquid like. This happens if the sugar concentration is quite low.
You want none of these two to happen. Instead, you’re looking for scenario 3 which is the crystallization of sugar on the surface of the cookie. It’s a bit like what happens when you’re making fudge. You want the concentration to be high enough so the excess moisture doesn’t soften the cookies but low enough that it doesn’t form a glass.
Expert kurma makes can judge that they have reached this stage by looking at the consistency for the sugar syrup. They are lowing for a thread. However, if you’re not (yet) as much of an expert, a thermometer is your best friend here. You’re looking for a temperature of about 112-113°C.
In-depth sugar science
If you’d like to learn more about this concept you might want to read our sugar science post. There we discuss the different stages of sugar cooking. Also, the effect sugar has on the boiling point of water is also used in ice cream (but instead of increasing the boiling point, it is used to decrease the freezing point!). Lastly, phase and state diagrams are very helpful to explain this in more detail.
- 225g all purpose flour
- 30g butter
- 30g shortening
- 60g cold water
- 1/4 tsp cinnamon
- 1/2 tsp ginger powder
- 1/4 tsp cardamon powder
- vegetable oil for frying
- 100g sugar
- 2 cm of fresh ginger chopped in small pieces (increase for a stronger ginger flavour)
- 100 ml water
- Mix the butter + shortening with the flour. You want to ensure that there are no large pieces of butter or shortening left in the dough. It might be useful to use a dough cutter here, but you can also just do it with your finger. The dough should look slightly crumbly at the end.
- Add the (cold) water to the dough and knead the dough into a ball. All you need to do is to make a coherent ball that you can roll out, do not knead it longer than necessary.
- You can now leave the dough to rest until you're ready to use it (if that will be several hours, store it in the fridge).
- Once you're ready to fry the dough, roll the dough out into a thin sheet (about 3-4 mm thick). Roll the dough thinner than you want the final cookies to be, they at least double in thickness during baking.
- Cut the dough into long strips of about 1-1,5 cm wide. Cut the strips into shorter strands (I tend to cut them in about lengths of 5 cm, but you can definitely make them longer).
- In the meantime, heat up the oil in a wok, deep fryer or deep pan. The temperature should be about 180°C. If you don't have a thermometer, throw in a small piece of dough. It should start bubbling immediately, but take a while to turn brown.
- Fry the cookies in several batches, such that the oil doesn't drop down too much in temperature when you add fresh dough (turn up the heat to high when adding new dough nd turn it down as soon as everything is in). Aim to keep the temperature between 160-180°C, the frying should take several minutes at least. The cookies will have to cook all the way through which will take a little while and should be a light brown at the end.
- You can start making the sugar syrup while frying your kurma cookies.
- Take a saucepan and add the ginger, sugar and water. Bring the mixture to the boil. Stir through slightly to ensure all the sugar is dissolved. Once it is dissolved, do not touch the pan, just let it boil.
- If you want to test whether there is enough ginger in the syrup, now is the time. Just take a little bit and taste to see if there's enough ginger flavour here. Kepe in mind that it will still concentrate slightly.
- Continue cooking the syrup until it is 112-113°C (233-235°F).
- Once it has reached its target temperature, immediately take it off the heat and pour it over the cookies*. It's best to stir through the cookies while pouring to ensure all the cookies get covered with syrup. Now continue stirring the cookies until the sugar starts to crystallize and turn whitish**.
- Leave to cool down. The sugar will turn hard and some cookies might be stuck together, just loosen them gently. Enjoy!
*If you want, you can take out the ginger pieces, however, if you've chopped them up fine enough, you won't really notice them and they give a nice extra kick/
**If you don't want to stir too much and too long, sprinkle a few grams of granulated sugar over your cookies after pouring in the sugar syrup. These sugar crystals will act as seeds for the other sugar to start crystallizing. As a result, the sugar turns white more quickly with less stirring (and potential breaking of the cookies).