ZeroPak Silicone Food Bags product reviews

Many years ago, while watching a cooking series, I was introduced to the concept of cooking sous vide - which is basically dry-poaching food by sealing it water-tight and then immersing it in a waterbath that stays at the set temperature. Cooking beef for example, you need to get the core of the meat up to 65 degrees minimum to kill harmful bacteria but any higher and you risk the meat becoming tough. Cooking it traditionally, you end up with the outer surfaces reaching far higher temperatures and becoming tough before the inside is even slightly cooked. Cooking it sous vide, the entire portion of meat never goes above the 65-70 degrees the water is at, so it cooks all the way through, slowly, and thus becomes tender. I knew I simply had to try it, but my early efforts were usually failures because of the resources I had on hand - It soon bvecame obvious that ziplock bags from the supermarket pick'n'mix section melt easily even at these low temperatures, causing the food to get contaminated and become inedible.

Now, at last, I had access to a waterproof, thermally-stable, food-grade container than had zero plastic in it! With great anticipation, I popped down to the butchers and bought some low-grade casserole-quality meat. This is the tougher cuts, which need to be casseroled to break down the connective tissue and make it soft and juicy. Cooking it in the pan or on the BBQ would only result in meat so tough and chewy you would be forgiven for thinking you had been served an old leather boot.

Putting the stove element on its middle setting gave me a steady temp of around 68 degrees in the waterbath, and after giving the silicone bag a good wash to ensure it was free from dust and any residue from the manufacturing process, I popped in my hunks of chuck steak into one of these bags, squeezed out as much air as I could, then dropped it into the pot for a slow and leisurely 6 hour spa treatment. At the end of which, I was greeted by some tender, succulent meat... that looked rather grey and unappealing. This is entirely normal - the idea being that you can choose to give the meat a final toss through a hot frying pan to put the colour on it. That took less than 5 minutes and enriched the visual appeal 10-fold.

Upon eating some, I was impressed at how easily the meat fell apart in my mouth, all thanks to slow, low cooking. I repeated the process with another portion of the same meat, but this time after marinating it overnight in some Thai-blend spices and coconut cream - also in the ZeroPak Silicone Food Bag. I decided not to transfer the meat to a new bag for cooking, instead removing all the air and again cooking it sous vide in the same bag it marinated in. The results were just as I hoped, and far better than I expected. All I had to do was up-end the bag over a bowl of microwaved 2-minute rice, and I was ready to eat!

I should point out here that because of the thermal tolerance of the sliding sealer-bar, I used a clip to keep it out of the water and away from direct heat - I would not advise immersing the entire bag underwater. Thus, I couldn't say from those tests that the bags are waterproof, so the next test was to fill a bag with water and seal it up, then lay it on a flat surface (the bottom of the bath in fact, for this test) and apply pressure to see if it would leak, split, or what. To my surprise, I was able to apply a lot of pressure - over 6kgs of weight was applied at one point - and the bags remained sealed and full of water. Nothing I could do, without involving sharp objects or excessive weight, would encourage even a single drop of water to escape.

Later, I tested the other end of the spectrum by placing the water-filled bag in the freezer for 3 days. As water freezes, ice crystals form an open hexagonal lattice that is actually less dense, and fills a larger volume, than liquid water. This is why ice floats, and drink bottles in the freezer come out looking bloated... or simply burst. Because the bag was totally full of liquid water when I froze them, I was half-expecting the bags to pop a seam or something. Nope... the bags simply stretched a bit and stayed intact. Exactly the result promised by the marketing, and lived up to entirely.

Overall, these bags provide everything they promise, and that is as it should be. They are highly functional, extremely durable, utterly flexible, and perfect for rolling up into your camping kit for storing leftover food or waste materials safely. I was fortunate to get one of each size - the 1 litre and the 1.5 litre bags - but plan to get some more of both sizes for my travels. My only issue was the sliding bar - silicone has a good grip to it, and as such the bar was prone to catching as I was trying to slide it open/closed. Following the advise of the agent, I dripped a couple of drops of water on the bags' upper seams, and that enabled the bars to slide more freely yet still retain a fully watertight seal. It's not perfect, and it's going to frustrate a few people until they understand why it's not actually a bad thing. If you want 'easy' - get a vac-packer. If you want portable and effective though, these are the very gadget you most need.