Crying in the Kitchen - Caramelized Onion Quiche

I cried last week... It was a long week, exhausting and tiring... But it wasn't the sleep deprivation that made me cry. It was onion.

A relatively volatile compound, propanethial S-oxide, is a lachrymator (not a nice word at all). Upon meeting the cornea, it is detected by the nervous system and triggers response from the tear (lachrymal) glands. The burning sensation is caused by the contact of the vapours with the moist surface of the eyes that results in the formation of sulfuric acid.

However, onions do not contain propanethial S-oxide. They only produce it when damaged, and its primary purpose is not to make humans cry, but to protect the plant from herbivores. The irritant is a product of a series of chemical reactions. When the onion is cut, its cells are broken open and this releases an enzyme called alliinase and water, both of which react with S-1-propenyl-L-cysteine sulfoxide forming a variety of products. These are precursors of different compounds which form the flavour of onion. They also include 1-propenyl sulfenic acid that reacts with an enzyme named lachrymatory-factor synthase (yes, I'm nearly finished), and gives rise to the evil propanethial S-oxide.

Well, the crying was worth it, my onion quiche was yummy...

Caramelized Onion Quiche with Cheese and Bacon

Ingredients
     Dough
300 g plain flour
125 g butter (softened)
100 ml water
pinch of salt

     Filling
150 g grated cheese (gouda/chedar/...)
150 g diced bacon
6 big onions
2 eggs
4 tsp. herbs de Provence
3 tbsp. brown sugar
olive oil
pepper
salt

Directions
1. Mix flour, butter, water and salt, and knead them into dough. Let the dough cool in the fridge while you prepare the filling.  
2. Preheat oven to 180°C.
3. Slice the onions, and slowly fry them in olive oil. When lightly browned, add the sugar and let caramelize a bit. Add the bacon and continue frying until the onion is soft and sweet.
4. Put the onion into a large bowl and let cool for a while.
5. Roll out the dough and line an oiled pie pan with it. Save the unused dough in the fridge.
6. Mix the eggs, cheese and herbs with the onion and add salt and pepper to taste.
7. Pour the filling into the lined pie pan.
8. Use the leftover dough to make a lattice top for the quiche crust.
9. Bake for about 35 minutes until the dough is golden-brown.

CNS Stimulating Mocha Cupcakes

Ivka, one of my lab friends, celebrated her birthday yesterday. She, as well as the rest of the serious scientists, cannot imagine a day without coffee. It is understandable, considering the hours spent in dark rooms, sterile environment without windows, and late afternoon and evening shifts... From all the different flavours of cupcakes, Ivka likes the mocha ones with espresso mascarpone frosting the most, and it was therefore the obvious choice for our little "lab-rat" celebration... 

C2H10N4O2, or caffeine, is a xanthine alkaloid compound found in the leaves and beans of coffee plant. It acts as a CNS stimulant in humans and, as such, it has the power to temporarily ward off drowsiness and restore alertness. Caffeine has several other names which are often mentioned when talking about its different sources. These include guaranine, mateine, or theine found in guarana berries, verba mate, and tea, respectively. From the evolutionary perspective, caffeine, commonly found in over 60 plant species worldwide, is believed to have a protective role, as it acts as a natural pesticide which paralyses and kills various insects.

Apart from caffeine, coffee also contains trigonelline, a bitter alkaloid which has a significant role in the development of flavours and aromas during roasting. During the roasting process, trigonelline decomposes and gives rise to a large class of aromatic compounds (pyridines). These are responsible for producing the sweet/caramel/earthy-like aromas.

The coffee aroma is perceived by two different mechanisms. We can sense the scent nasally via smelling the coffee through the nose, or retronasally, when we swallow the coffee or when it is present in our mouth and the volatile aromatic compounds drift upward into the nasal passage.

Mocha Cupcakes with Espresso Mascarpone and Dark Chocolate Frosting - Notice the beautiful new cases! 

Ingredients (makes for about 12 cupcakes)

     Cupcakes
2/3 cup plain flour
1/2 cup brown sugar
1/4 cup cocoa powder
1/4 cup butter
1/4 cup whole milk
1/4 cup strong black coffee
0.5 tbsp. baking powder
0.5 tsp. vanilla extract* (not the Dr.Oetker clear essence!)
0.25 tsp. salt
0.25 tsp. baking soda
1 large egg
*the only good vanilla extract I discovered in CZ/SK so far is the one from Marks and Spencers, in the UK I like the one from Dr.Oetker (brownish and thick, available with, or without the vanilla seeds)

     Espresso Mascarpone Frosting
200 g mascarpone cheese
6-8 tbsp. powdered sugar
2-3 tsp. instant coffee powder
(1-2 tbsp. heavy cream if the frosting turns out too thick)

     Dark Chocolate Frosting
40 g quality dark chocolate (melted)
2/3 cup cocoa powder
1/2 cup butter (softened)
1/3 cup heavy cream
4-6 tbsp. powdered sugar

Directions
      Cupcakes
1. Preheat oven to 180°C
2. Whisk together sugar and softened butter
3. Add the egg and whisk to blend
4. Add tepid coffee, milk, and vanilla extract and mix thoroughly
5. Mix the dry ingredients and slowly add the dry mixture to the wet one, whisk thoroughly until smooth
6. Line a cupcake/muffin pan with cupcake cases and fill each one a about 2/3 full
8. Bake for about 20 minutes (toothpick inserted in the centre should come out mostly clean)

     Espresso Mascarpone Frosting
1. Whisk together mascarpone with the instant coffee powder
2. Add sugar (less if you like your coffee more bitter) and whisk to blend
3. If too thick, whisk in some cream

     Dark Chocolate Frosting
1. Whisk together the softened butter and cocoa powder
2. Add melted chocolate and cream and mix thoroughly
3. Stir in sugar and beat until smooth