Are vacuum sealers necessary?
In short, it depends.
A vacuum sealer isn't necessary if you cook for immediate serving (''cook-serve''). Good quality, resealable, food-grade plastic bags with the water displacement method works well.
A vacuum sealer is recommended if you intend to store sous vide cooked food for a prolonged time for consumption later (long term ''cook-chill''), or use advanced techniques such as food compression and flash-pickling (which requires a chamber vacuum sealer). We recommend exploring these at a later stage once you become more familiar with the cook-serve method.
The purpose of minimizing the air in the bag is to ensure an efficient heat distribution from the sous vide water bath to the food for even cooking, as air is a poor conductor of heat. This is also the reason why you can survive in a sauna at 70°C (158°F), but scald your fingers if they are dipped in a water bath for a few seconds at the same temperature.
Vacuum sealer options
Although bulky and expensive, chamber vacuum sealers are very effective at making bags vacuum-sealed. Given the large chamber, multiple bags can be vacuum-sealed at once and liquid marinades in the bag would stay put. Its ability to pull a strong vacuum enables other advanced techniques such as food compression and flash-pickling. These are generally used under professional settings.
On the other end of the spectrum are the compact hand-held vacuum sealers that work with special resealable bags with a valve. Hand-held units are affordable but the strength of vacuum is weaker and quality varies by manufacturer. It may be tricky to seal food with liquid, but this is easily solvable by freezing the liquid marinade in ice cube trays beforehand. For those just starting to cook sous vide, hand-held vacuum sealers offer a cost effective solution.
Clamp-style vacuum sealers are also relatively compact but operate using heat sealing of pouched (without a zip seal or valve). Similar to hand-helds, sealing food with liquid is tricky but you can freeze the liquid marinade beforehand. A clamp style vacuum sealer is traditionally recommended to small catering establishments.
The water displacement method
With sous vide cooking, vacuum sealers are optional for most cases, unless you require prolonged storage of food cooked sous vide. This is explained in more detail in the previous section. A simple water displacement method works for sous vide cooking - you'll master this with just a bit of practice. It's best to start with a large bowl of cold water to do this.
Here's how you do it:
- Place ingredients (in this case duck breast) into a food-safe resealable freezer bag.
- Seal the lip of the bag, leaving a small hole unsealed at the end.
- Press to flatten food evenly and push out most of the air.
- Submerge bag in a large bowl of water until it reaches just below the zip closure. The water will push out most of the remaining air from the bag.
- Seal the bag completely, sit back and enjoy.
At its simplest, brining is the act of soaking meat in a solution of water and salt, while refrigerated. Brining makes leaner cuts of meat (such as pork, fish and poultry) juicier as some of the brine solution is absorbed into the meat, but more importantly it improves moisture retention when cooking.
Composition of brines vary widely. They are typically a 5% - 10% salt solution (50g - 100g salt per litre of water), but you can be quite creative here by adding other flavourings (e.g. sugar, herbs and aromatics) which you'd like to impart to the meat. If adding complex flavourings, make sure the brine is heated beforehand to 'activate' the spices and seasonings better. But only add the meat in once the brine is cool!
The length of brining time depends on the type and size of meat. Delicate seafood like shrimps or fish takes 20 - 30 minutes, slices of poultry or pork is perfect brined for 2 - 3 hours, whereas larger cuts such as pork shoulder or beef brisket can be brined for up to 2 days.
Brining is easy and economical: all you need is salt, water, a large bowl and a refrigerator.
- Once the salt (and other flavourings, if added) is dissolved and the brine is cooled to room temperature, add in the meat to the brine.
- Make sure the meat is completely submerged in the brine. Cover with cling film and refrigerate until use.