As a food lover there's nothing better then learning
new techniques to improve my own cooking.
I love experimenting with food and new dishes and over the last three years I have been reading and learning about Sous Vide cooking and molecular gastronomy. During the course of this gastronomic adventure I have started to study the science and chemistry behind the cooking.
Below is one of my most popular posts relating to my research in perfecting Chinese crispy roast pork crackling (Siu Yuk).
The Great Food Experiment 1 - Chinese Crispy Roast Pork
So we can denature the skin by scoring, piercing, heating and using chemcials to attack it.
So here I have two pieces of pork belly and I plan to divides these into 8 pieces and prep each one slightly differently to see which gives the best cracking results.
so here's the fat layer on my pork bellies.
I boiled 5 litres of water
put the pork bellies on a wire rack in the sink and slowly pour the boil water on to scald the skin. The skin contracts a lot when you do this.
lots of steam
I cut the flesh in 1 inch sections down to the first
so far this is a pretty typical siu yook preparation.
Now I divide the pork bellies into 8 pieces for
my 8 tests.
Test 1. make more score lines both horizontal and vertical, this will be my control piece.
Test 2. use a blow torch and lick the surface of the skin with the flame until I see the skin dry and change colour but I don’t burn or blister the skin.
Test 3. brush lemon juice on. As it is acidic it should denature the skin.
Test 4. brush vinegar another acid to denature the skin.
Test 7. brush alcohol – 40% vodka – dehydrates and denatures proteins, although I read that I actually need a 70-80% solution to really do the job.
Test 8. brush kiwi juice - contains a protein digesting enzyme called Actinidain and i use this to tenderise tough cuts of beef.
so here are the 8 piece on a platter
ok! I just cooked my pork bellies.so took the bellies
out of the fridge and then lightly sprinkled some more salt on the top.
Even before I finished cooking I could already see
which ones were working and which weren't.
The results are as follow.
and here is a cross section off all of them together
TEST 1 - BLOW TORCHED SKIN
torched skin after 24 hours in the fridge
out of all the pieces this was pretty much the driest skin, touching it you could tell if was very dry and hard.
had a pretty even bubbling and colour
torched cross section
TEST 2 - LEMON JUICE
lemon skin after 24 hours in the fridge
this looked dryish but the skin still had some suppleness.
good crackling again not as even but good colour
TEST 3 - VINEGAR
vinegar skin after 24 hours in the fridge
similiar to the lemon skin but seemed wetter still.
pretty similiar to the lemon in colour and blistering
Verdict: this crackling was lighter and had a softer crunch compared to the lemon crackling.
TEST 4 - KIWI
kiwi skin after 24 hours in the fridge
the skin was the wettest out of all of them
err..... picture says it all, it didn't form crackling but instead turned into burnt plastic skin.
TEST 5 - VODKA
vodka skin after 24 hours in the fridge
this was surprising, as the skin seemed pretty dry
very even crackling and colour whilst this was cooking i could see this was the one that was forming the most uniform crackling
TEST 6 - BAKING POWDER
baking powder skin after 24 hours in the fridge
skin was pretty dry and seemed hard, not very supple.
baking powder crackling
This looked like it was forming good crackling at the end of the designated cooking time but the middle still hadn't blister completely so I left it under the grill for a further 3 minutes. End result was not as even colour or blistering.
baking powder cross
TEST 7 - LYE WATER
lye skin after 24 hours in the fridge
this skin was very dry and took on a hard waxy appearance
hehehe a picture says a thousand words? this was
easily the best crackling in colour and blistering,
TEST 8 - SCORED
scored skin after 24 hours in the fridge
this still looked pretty wet in comparison to the torched and alkaline brushed pieces.
this one had the best golden colour and even blistering but might have been due to the fact it was the middle piece. I scored this one a lot more in both horizontal and vertical directions.
This was great fun :) and the winner of the best
crackling was easily won by the Lye Water.
So it looks like the chinese restaurants were right
about lye water.
Surprisingly the best siu yook in my opinion was my wild card vodka as it had the best colour and crunch and most even blistering and still had the crackling attached to the meat. Think i will repeat this using a 60-80% alcohol solution next time and pit it against pure baking soda and lye water.
the worst one was the kiwi as it just started burning rather then blistering.
so my order of preference
BTW just to clarify apart from the kiwi all the
other 7 were really sucessful.
I will repeat this experiment again next month with
the following changes
1. lye water
and leave them for 2 days in the fridge.
If anyone has any observation or suggestions please let me know :)
© 2010 Samuel Tsang. Illustration copyright © 2010 Samuel Tsang.
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