A Sous Vide Diary: Roast Pork Belly (Sio Bak)

Wednesday, January 04, 2012

(I have since improved on the recipe further. Read it here.)

I continue with my diary on my experiments with Sous Vide cooking.

It has become an indispensable tool in my kitchen and it will be used for this coming CNY dinner. I have said more about it here.

As I have mentioned before, we are getting a glimpse of the modern home kitchen in Sous Vide. But you should not be pressured into jumping on the bandwagon unless you think it will work for you.

Don't expect SV gadgets to be featured by all those lovely elderly housewives pushing the latest woks and pots at the super stores. It will still take some time for the pool of home cooks out there to understand this cooking method.  

After all, cooking appliances like the microwave, oven steamers and pressure cooker have been here for many years now. These are not like communication IT gadgets, where you may feel left out if you ignore it for too long. Till today, these appliances are still catching on for many.

So, take your time. I like the Sous Vide Magic a great deal and I think it suits my home kitchen perfectly. It has a geeky feel and can do with some improvement in design elegance. But as my wife has said, it is easy to learn using it - just press buttons. If I can get round to some demos for some friends who are interested, it may help.

I have been using this gaadget to cook dinners for many gatherings by now. Of late, new dishes which I had success with includes a beef short ribs dish which turned out spectacularly (will blog this soon) and Chinese Roast Pork. Please note this: as with every other method of cooking, you will need time and experience to master this technique. So, be patient. And for most recipes, SV does not replace but complements. For Roast Pork, the oven or pan is still used to crackle the skin and the fridge for drying.

Sio Bak (or Siu Yuk if you are Cantonese) is one special pork dish where the skin should receive some well deserved crackling attention. I have no recollection of my Mum making this. But as a boy, I was always very fascinated with the whole roast pig which was offered to the gods on the 8th day (my mother is Hokkien) of Chinese New Year.

So, I had to cobble together recipes I could get hold off, including ideas from David Chang of Momofuku, Thomas Keller, Ieat interesting post on the Chinese version and also a Sous Vide version here.  

The marinade is straightforward: definitely 5-spices with added salt and pepper if you are going for a Chinese or local version. This is simple enough. But a good Sio Bak goes beyond just a crackling skin. The meat needs to be moist with the right texture. 

The challenge lies in crackling the skin without drying out the meat.

Meat loses its moisture when it is cooked because of constriction. The higher the heat, the more moisture it loses. It is the same in the oven or a vacuum bag. It is a common misunderstanding that the vacuum bag keeps the meat moist. Get your temp too high or cook for too long, and your SV meat will be overcooked or drier. You can tell this quite easily as moisture loss can be seen as it's trapped in the bag. The amount of water indicates the extent of moisture loss.

I have had some expensive steaks ruined by using the wrong temp or spending too long a time on the bath. A tender cut of good steak like Rib-eye of less an inch in thickness should spend no more than 45 minutes in the bath. This is my opinion anyway but it comes with experience. Don't cook a leg of spring lamb (1 kg+) for more than 6 hours. Follow some websites which recommend a minimum 24 hours and you will end up with mushy lamb.

Coming back to roast pork, SV cooking can be used to cook the meat just right. And then you use the oven to crackle the skin. But the skin needs to be dry enough to crackle. Leaving it skin side up in the fridge for a few hours or overnight will do the trick. Or a good two hours in front of a fan or using the oven blow-dry method (the oven is a great dehydrator: switch on at low temp). Or hang it up in a dry place.
Pressing the slabs of pork using the granite mortar!

After that, roast it skin side upwards in the oven for about 15 minutes. These are the steps I use:
  1. Have the butcher cut up the meat into 4 to 5 in square blocks (to fit into my rice cooker). Choose pork belly cuts which are even. A kilo slab can be cut into two square blocks. 
  2. Then  marinate (5-spice powder, salt and white pepper). For better presentation, you may want to have the slabs pressed flat and you can do it but putting some weight on the top tray for a few hours in the fridge, as can be seen in the photo.
  3. Then, vacuum pack it and SV for 6 hours at 72 C.
  4. Next,  dry up the skin using some of the methods mentioned. I leave it for overnight at the top of the fridge. 
  5. Then grill the skin side up in the oven for about 15-20 minutes at 200 C. Cooked skin crisps easily. If some parts of the skin are still soggy or soft, just grill longer. It is okay to have charred bits as they can be easily scraped off. 
  6. Remember that it is easier to cut the pork when it is lukewarm or cold. Cut the pork meat side up with the skin on the chopping block.    
Leaving at the top shelf of the fridge overnight to dry the skin
To summarise:
  1. SV (6 hours at 72C))
  2. Dry Skin (Fridge or fan)
  3. Oven (20 mins at 200C)
You need to plan ahead but the execution is quite stress free with consistent and predictable results. I did it for a party of 10 recently and they were satisfied diners.

After the SV cooking and a few hours in the
fridge to dry the skin. 
If you have an SV set up, you may want to give this a try. It does make for a good CNY dish and I will be doing this. Now, the Pork Belly Bun (recipe here) tastes superb when you use this. The crackle of the skin, crunch of the spring onions, cucumber along with the superb sesame sauce makes this a winner.

When I do get round to making it with a non-SV method successfully, I will blog it up.I have to admit that the SV method gives me the control I need and I doubt I will be enthusiastic with other methods. I remain open to other ideas to improve on this recipe or variate.

It is gorgeous when served with Mantou (steamed bread) with a dash of good sesame Peking sauce and veg

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  1. Hey! Im a great fan of your blog and I really do admire all your recipes. Im intending to try out this recipe for an upcoming get together but im quite worried of getting something wrong, so would like to ask for some advice if possible!

    Firstly, you mentioned that the meat should be cut lukewarm - is that before or after grilling?
    Also, do i just sprinkle the seasoning prior to SVing? Do i just sprinkle it evenly on all sides? Lastly, how should the salt rub before grilling be done - do i just rub heaps of salt or do i have to leave it there for a long time like curing? Lastly, how many people can 1kg of belly feed?

    Thanks so much for all the help! Im cooking for a group of frienda and we are all abroad and missing good food and so im really worried il screw up, but i really appreciate your advice!

  2. WIll be glad to help:

    Firstly, you mentioned that the meat should be cut lukewarm - is that before or after grilling?
    - After.

    Also, do i just sprinkle the seasoning prior to SVing? Do i just sprinkle it evenly on all sides?
    - before SVing, just drop the salt and spices into the bag. The 6-hours in the bag= pork brining in the salty/spiced liquid. Not necessary to rub.

    Lastly, how should the salt rub before grilling be done
    - Rub a generous amount of salt onto the skin just before u grill

    Lastly, how many people can 1kg of belly feed?
    - assuming 150-200gm per pax, about 5-7. Depends what else you are serving.

    Have fun. It takes a few tries to get it perfect but nothing can go seriously wrong with this recipe.

  3. I love your recipe and totally agree that when cooked for long period makes the meat mushy, same as chicken (chinese style) and texture is alien to our normal taste buds. More recipes from you please. Jeff

  4. I love your blog.
    I saw you served with mantau. How do I make the mantau in semi circle without them sticking together when steaming? Shirl

  5. dip chopstick into some oil and fold the round dough over it.

  6. This is an old post so I hope you would still reply. I've been attempting sous-vide siobak for the longest time but haven't had success with crisping up the skin. I do SV my pork belly for a long time so the meat is fall-apart tender. But the resulting skin is gelatinous and impossible to crisp beyond a superficial layer if I resorted to deep frying it. I'm looking for a thicker thickness of crispy, if that makes any sense. Sounds like that's where I'm messing up mostly - should try a shorter cooking time like the 6 hours you suggested.

    Anyway, my question is do you let the refrigerator-dried pork come to room temp before putting into the 200C oven? Or do you go straight from fridge to oven?

    And I saw one of the comments asking about salting pre-grilling - so you do pack on a layer of salt just before grilling and then scrape it off?

    Thank you for your very informative post!

  7. Dear m- straight from fridge to oven is ok. No need to salt the skin before grilling. Meat should not be falling apart.