Once you’ve delved into sous vide, you discover that foods seem to fall into two distinct categories. Not meat and starch. Not land and sea. It turns out that some foods SINK, and other foods FLOAT. Most of us never made this distinction before, or even put any thought at all into it. It never mattered before sous vide.
But, in sous vide, IT MATTERS. If your package is not fully submerged, there’s no way of knowing if the tip of that iceberg is at a safe temperature. And, it’s probably not.
Sometimes it matters more than others. If that food is celery, or carrots, chances are you won’t be exposed to any harmful pathogens. But your food won’t cook evenly, and that negates the benefits of sous vide too. I get questions about it all the time in the GROUP, so maybe we can shed a little light on it here.
Just how much air is in the bag is directly related to whether or not your package will cooperate with your efforts to submerge it. You don’t have to learn much about sous vide to find that out. Chamber vacuums spoil us, because they are really good at removing not only the air in the bag, but the air in the food itself. Almost anything will sink after the Vacmaster treatment.
There’s only one problem. Those chamber vacuum machines are EXPENSIVE. Especially when you compare them to Ziploc Freezer bags, or even the FoodSaver system. It’s hard to justify investing in a chamber vacuum unless you do a LOT of sous vide. I do a lot of sous vide, but I never got to the point where I could put that kind of money in. Eventually, I got gifted one, and, I gotta say, I feel blessed. They are really convenient. They are also large, and they weigh a ton, and I worry a little bit about breaking it, wondering if I should change the oil and so on. So, we’re going to pretend that chamber vacuums are not available. For most of us, that may as well be true.
Marketing drives our daily lives, there isn’t much controversy there. Manufacturers of channel vacuum machines promise life changing results to those who commit to buying their stuff. It’s kind of like computer printers. You can pick up an awesome printer for less than $100, just wait until you have to buy some ink. And so it goes with channel vacuums.
The machines are reasonably priced. But you MUST use those waffled bags, and they get almost as expensive as a chamber vacuum; they just do it gradually. I figure it takes 6 years to pay off a chamber vacuum with the money we would save avoiding the purchase of those cumbersome sleeves that we always cut too short or too long. That’s right, I do it too.
Anyway, channel vacuums don’t really create much of a vacuum in the bag. They remove excess air, but the atmospheric pressure inside is the same as it is outside, not matter what they tell you. They might seal, they might not. They might seem to seal, and leak later. What little pressure is exerted inside that waffle bag serves only to create pressure against the seal. You can double seal, but the strip gets hot, and then you have to wait for a while.*sigh* smh.
I used channel vacuums longer than I should have. With the exception of preventing freezer burn, Ziploc Freezer bags work just as well as waffle bags, once you get adept at using Archimedes’ principle. Archimedes was the guy who said “Eureka” when he realized that getting into a bathtub of water displaced exactly the volume of one’s body. I always wonder just how much they bathed back then, anyway, but that probably doesn’t have much to do with anything. Archimedes was also the guy who said “Give me a lever and a fulcrum, and I will move the world.”
Ziplocs are kind of boring and unromantic. I always tell people that the FB group that I admin is where romantic notions come to die. Ziplocs work fine, and I still use them for some things even though I have the chamber vacuum now. You can get pretty good at dipping the package in water and then zipping up just at the last second.
So, why am I still so frustrated?
Some foods are just less dense than water, and that’s all there is to it. Air is usually the culprit. Corn, celery and artichokes have a lot of air trapped in them. Enter the Texas Shark Cage.
My Dad and I didn’t have much in common, but we used to watch Wrestling together, back before it was fake (yeah, right). Back then, they had a novelty event called the Texas Cage Match. The contestants would be “locked” into a big cage the size of the ring, to add to the drama. It was great fun. And anybody whose ever watched the movie “Jaws” or PBS or one of those other nature channels has seen those cages that they put the divers in to protect them from the sharks. I’m not even sure that sharks are more dangerous than humans, we’ll have to ask the baby seals about that one. Anyway, this principle can be applied to our stubborn sous vide packages.
It’s great to have a rack on the bottom of the bath to prevent sous vide packages from settling down there and cooling off, which they will do. But there’s isn’t much risk of that happening if your package is determined to float. So, one day, in between cups of coffee, I had the bright idea to do this:
Big deal, I know. It works, sometimes, but it’s not completely fool proof. You may still have to put some weight on top. I started experimenting more with it, you know, putting a bunch of racks on top, putting the lid on, putting another vessel on top to squeeze everything down. Deep down, I too am a hack.
Soooo, I gathered up a bunch of vegetables, some sinkers, mostly floaters. I crammed them into the largest Lipavi rack I had, and bound the whole thing up with those little plastic ties. Then, I carefully flipped it as I lowered it into the bath, like deep sixing a lobster trap. The one rack insert in the middle eventually came out when I finished later, but it all held together for the most part.
And, yes, I put some spare racks on top, and filled the vessel as full as possible. Sometimes I fill the vessel over the fill line on the device, but I wouldn’t recommend it. The Joule seems to tolerate this practice the best. As far as I can tell, it doesn’t HAVE a max fill line.
I decided that if had some bigger ties or clips, it might work better, and I might not have to flip the cage when I put it in the vessel. It’s a work in progress.
And there’s more!
Sans vide can help with this problem. If you just don’t have the wherewithal to jump through all these hoops, you can put enough water in the bag to sink the corn, artichokes, celery, whatever. That’s not really sous vide, but you can treat the water like stock when you’re done. Your food will still benefit from being cooked at a precise temperature. It works, it’s good, I do it. Lazy, maybe. Impure, if you say so. We do what we gots to do.