Sous Vide

How to Use Glass, Not Plastic, to Sous Vide Food

July 20, 2017

For many people, the words “sous vide” are linked closely with plastic bags—but it doesn’t need to be. The technique got its name because the original chefs used vacuum sealing bags, effectively letting the food bathe in a water bath at a stable temperature without actually touching or mixing with the water. It’s more about maintaining a consistent temperature than using a vacuum.

Some chefs are using glass containers like canning jars or pyrex casserole dishes as vessels and getting the same results, because the power of the method depends upon the precise temperature delivered by the water bath. Some still call this glass container method “sous vide”—“under vacuum” in French—even though there’s no vacuum or bags involved; others have adopted terms like “precision cooking” to be more accurate.

Glass containers with no vacuum may seem like a radical shift, a change that abandons all of the past traditions, but that’s not so. The point is still to bring food to very precise temperature, and switching to glass has some advantages.

The first and most obvious is that glass can be reused easily. Cleaning and reusing glass saves the cost and time of buying new plastic, while reducing the carbon footprint and saving space in the landfill.

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Top Comment:
“I did use plastic bags, but I ran across a recipe for creme brulee made in glass jars in a sous vide. They looked delicious! I love the idea of doing sous vide eggs in little jars. I'll have to try it!”
— Julie
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Using glass also relieves some of the anxiety about cooking in plastics. It’s difficult to generalize about the effects that the cooking container can have on our health, but some worry that plastic releases harmful chemicals. Of course, glass is not perfect either, but it has a well-known and long history of being stable under a wide range of temperatures.

You can use jars for sous vide eggs, salmon, and more. Photo by Julia Gartland

Many aspects of using glass aren’t that different from using plastic bags, but after a few months of experimenting, I can report that there are some differences to keep in mind:

Pay Attention to the Air

Plastic bag users don’t need to worry about the air expanding as it warms up, because the sous vide technique usually removes the air. That’s what the vacuum (vide) in the name is all about. But glass is different. Home canners know not to tighten the lids of the jars until the water is hot, but non-canners need to be reminded to leave some slack so the air can escape.

Jars Can Float

I often let canning jars float in the hot water, something that usually works well, even if the jars are relatively full with food. This lets the water circulate along the bottom too, creating better thermal stability.

Glass Has Thermal Mass

When you take it out of the cooker, it will retain some heat, much longer than plastic bags. If you’re not careful you may get burned.

Glass Is Also An Insulator

Glass doesn’t convey heat very quickly. It’s not like metal. Cooking in glass just requires more time.

Most of my experiments with a well-insulated water bath show that the food reaches the right temperature within 30-45 minutes. Your results will vary. A big chunk of meat from the refrigerator or freezer will take much longer than one that is already room temperature. If your vessel isn’t well insulated, the heater will need to work harder to maintain the temperature, because the sous vide water heaters only put out a fixed amount of heat.

Contact with the Glass Is Important

The main reason cooks suck the air out of the bags is to increase the contact with the water bath. Since the heat takes longer to pass through the glass to the food, cooking something like a rib roast is tricky because the glass vessel is more like an oven. The heat doesn’t move through conduction, but through hot air. The casserole dish in a sous vide water bath becomes a small oven with natural convection.

Liquid Sauces Can Help

Some recipes, like Coq au Vin, lend themselves naturally to the medium. The liquid carries the heat to the meat.

Air Can Encourage Drying Out and Oxidation

I’ve cooked venison in a jar with some of its own juices. The meat below the liquid line stayed red, while the meat above turned brown and began to dry out. Pay attention to the liquid level.

But Drying Out May Be What You’re After...

Many sous vide recipes concentrate on marinades and sauces because they work well in bags, but some food like baked potatoes or simple roasted meats may be better dry. Unlike sealed bags, unsealed glass allows some of the liquid to evaporate, an effect you might want.

Closed Tops Matter

If some of the glass vessel protrudes above the water line, the temperature of the air will affect the process. This is why I use an insulated “cooler” with a tightly fitting lid. This keeps the air around the same temperature as the water and it reduces the amount of energy that’s wasted.

Canning Jars Could Be Sterile

Although I’ve eaten everything I’ve cooked immediately, some friends use small canning jars to make egg dishes once a week so they can grab one on the way out the door to work. Using glass jars in hot water isn’t very different from canning vegetables. A regular canning lid will form a vacuum seal as it cools. It may be a mistake, though, to assume that the food can be stored on an unrefrigerated shelf, because the sous vide temperatures are much lower than traditional canning with boiling water. For this reason, my friend refrigerates his sous vide eggs.

Have you tried using glass in your sous vide adventures? Let us know in the comments!

See what other Food52 readers are saying.

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Peter Wayner is the author of more than a dozen books and a frequent contributor to publications like the New York TImes, InfoWorld, Wired, Technology Review and more. He lives in Baltimore with his wife and two hungry children.

31 Comments

frostysuzy December 16, 2021
Hello, do you recommend a particular cookbook that concentrates on using glass jars vs. plastic? Just beginning this endeavor!
 
Carroll B. October 30, 2019
I just bought some very small glass canning jars to sous vide eggs and was very pleased with outcome. But it is a bit pricey to change out lids with every use, so I wondered how many times I could use the canning lids. I have used them twice so far. What do you think?
 
littlecottage January 4, 2020
you are not actually canning with these jars so you can reuse the lids as often as you want but make sure that you watch the rubber seals and that there are no lifted edges if the rubber gets thin you might get leakage
 
Coral May 5, 2019
What would happen if you sucked the air out of a mason jar and tried to cook (sous vide) in an airless glass jar? Are you risking broken glass? Will the airless environment make the process more like using plastic or silicone?
 
Valerie December 19, 2018
If you use Pyrex glass containers, what lid do you use?
 
Peter W. December 20, 2018
The usual baking ware. If they don't have a snug fitting top -- and many don't -- I just let it float on top of the water. The temperature is still pretty constant.
 
Elaine May 30, 2022
Can you elaborate on this more? I want to use glass but I'm confused as far as using a lid. Most of them are plastic so it seems to defeat the purpose of using glass. What do you mean you "just let it float on top of the water?"
 
Peter W. May 30, 2022
Yes, some have plastic lids but there are some with glass lids too. Canning jars tend to have metal lids and that often means a coating of plastic.

Floating just means that it's not necessary to keep them submerged. It's all about making sure the temperature is constant.
 
Elaine May 30, 2022
Can you point me to where I can get a glass container with a glass lid that would be big enough for a steak (or even a roast)? I have searched all over and haven't even found small glass containers with glass lids.
 
Peter W. May 30, 2022
Not immediately. But many pyrex roasting dishes have glass lids. They may not seal completely and so you don't want to fully immerse them.

In cases like this it helps to use a pretty sealed sous vide rig. Mine is a converted cooler normally used to hold drinks in the summer. This prevents much of the heat from escaping and keeps the interior about the same temperature.
 
Peter W. May 30, 2022
BTW, when I cook meat lately, I use a MagicChef pressure cooker with a sous vide option. The model I use has a temperature control circuit with one degree (F) precision. I don't use any water and just put the meat in the stainless steel insert. The temperature control is pretty good, although I've experienced issues at time.
 
Elaine June 7, 2022
I took your advice and bought a MagicChef with the sous vide option. You don't use any water? Can you tell me how the meat turns out compared to sous vide the normal way in water?
 
Peter W. June 7, 2022
Well, I'm curious to hear your experience. I just plop the meat in like it's a stainless steel roasting pan that might be going in the oven. Sometimes I add some pearl onions or mushrooms. But instead of putting it in the oven, I put in in the MagicChef and wait. I tend to set beef and venison to 132. Then I give it a bit longer than most because the heat doesn't flow very quickly when there's not a big thermal difference. You can experiment with time.

I've also learned that I need to flip the meat every 2-3 hours because the system is not really designed for cooking sous vide without water. So a thermal gradient develops and it's just a bit cooler toward the top of the chamber.

I've had good luck with chuck roasts set to 132 degrees over several hours. You can use a thermometer to make sure that the inside of the meat reaches 130-135 degrees. (Higher, I guess, if you don't want medium rare.)

Pork and chicken are a different story. Generally pork at 140 is firm and 150 is more shredable. Chicken is still a mystery for me. My wife likes to use the pressure cooking feature and be done with it.

You asked how it compares. I would like to believe that the thermal process is the same. But I also don't think that the waterless process has the same thermal precision. The water has a large thermal mass and that just keeps the temperatures more stable.

A deeper question is whether the vacuum and the plastic bag push any marinades and seasonings into the meat. That doesn't happen at the same rate, I'm sure. But your results might depend upon the recipe. I'm very focused on getting the temperature right for the meat, not putting together the whole package.

Let me know your experiences either here or to my direct email.
 
Elaine June 9, 2022
OK my experiment is on today. I have a 1# Strip steak that will be my test in the Magic Chef. I like my meat medium so (according to directions) that would be 135º but I'm unsure of how long of time this will take. One recipe in their book says 45 minutes...hummmm? I'm new to Sous Vide anyway so this is just a real learning experience in all ways. If there was just a really SAFE container to do it in, that would solve everything. So based on your experiences, what time frame should I be looking at?
 
Peter W. June 9, 2022
I would use a thermometer as the ultimate judge. For steaks about an inch or so thick, I've found that two or so hours may be enough for the middle to reach the desired temperature with one or two flips in the middle. The starting temperature makes a big difference. If you're going from the freezer, it will take much, much longer. If you've let it come to room temperature for a few hours, it could be shorter. Test often with the thermometer, and you'll start to get a feel. It took me a bit of time to get the hang of it.

For roasts and things like pork loins, I often leave them in for 12-25 hours. This sometimes starts breaking down the proteins in other ways.

The key thing is the temperature.

Let me know how it goes.
 
Elaine June 10, 2022
Well the steak came out wonderful! I put it in for 2 hours like you suggested. I then seared it in a cast iron skillet to get the brownness. My mistake (because I was gone) was not checking the temperature a few times before the end of the cooking time to see when it hit the goal temp. First of all, Sous Vide is new to me and then trying it in the Magic Chef is really new to me so I'm trying to figure it all out. My main reason for trying Sous Vide is because I could never get a steak cooked right - it was either overdone or under done...So if I had to put one term on the benefit of Sous vide, it would be "keeping the temperature/doneness at a certain point" - correct? I am now going to try a beef roast and check the temp more often. Do you place the meat on the rack or right on the bottom of the pan?
 
Peter W. June 10, 2022
Glad to hear that it went smoothly. One of the nice things about precision cooking and sous vide technology is that you don't have to be as careful with the cooking time. Certainly cooking a steak on a hot grill can be frustrating. Take it off too soon and it's rare. Wait too long and it's lost. Since the chamber is set at, say 135 degrees, adding an extra 20-30 minutes shouldn't make a difference.

That being said, I've done some very long pork roasts and time can affect things. But it's not as nerve racking as cooking over a hot grill.
 
Elaine June 10, 2022
Wondering though - do you put the meat on the rack that comes with the appliance or do you put it on the bottom of the pan?
 
Peter W. June 10, 2022
I try to have as much contact with the bottom as possible for heat transfer. The chamber doesn't seem to have as uniform a temperature as I would like. But it works pretty well.
 
Elaine June 15, 2022
Well, I tried a roast too, specifically an Angus London Broil, 1 ½ pounds and it came out really good! It reached goal temperature in a little over an hour which really surprised me. I've had it in my head that cooking this way takes a long time but it appears that it doesn't, at least not by this method. So I think I'm sold on the MagicChef but when it comes to the Sous Vide feature, I would tend to use it more for steaks. That's always been my problem - either overcooking or undercooking steaks. Roasts I really like in a slow cooker so I may stick to that. The Magic Chef cost me $100 and has 9 features. The Sous Vide appliance cost me $130 and it only does one thing plus I don't like the plastic bags. Any comments about any of my comments are always appreciated!
 
Peter W. June 15, 2022
The temperature is always the first goal because it determines the character of the meat. I've found that the start temperature and the shape of the cut make a big difference.

Some people vary the amount of time at the goal temperature because the proteins can break down a bit more. I haven't experimented with them enough to be certain, but I'm sure that much of it depends upon individual taste.
 
Elaine June 15, 2022
Thank you for all your help and recommendations - I would have never known about the Magic Chef for sous vide if it weren't for you!
 
Cookies July 1, 2022
Rubbermaid now makes a “brilliance” collection of oven and freezer safe glass dishes with glass lids. I just bought some at Kroger that hold a little over 4 cups each.
 
Cynthia February 26, 2018
Will preheating the glass in the sous vide water before adding the ingredients help achieve penetration more quickly?
 
Peter W. February 26, 2018
Penetration of what? The heat? The flavors? If it's heat, it will speed things along a bit. But it will probably make the glass a bit harder to handle because it will be between warm and hot.
 
Julie July 21, 2017
I just opened up my Anova yesterday and made chicken and eggs by sous vide for the first time! I did use plastic bags, but I ran across a recipe for creme brulee made in glass jars in a sous vide. They looked delicious! I love the idea of doing sous vide eggs in little jars. I'll have to try it!
 
Alexis A. July 21, 2017
thanks for the article! i'm always intrigued by sous vide cooking, but have not undertaken the endeavor yet myself. I've never considered using glass, as like with many other, i associate the cooking in plastic vacuum sealed bags. But then i think about the glass egg coddlers i see and it's essentially the same thing. i think this technique works for the smaller stuff, but cooking a rib roast this way seems too akin to cooking in a convection oven that i doubt i would bother.
 
Peter W. July 23, 2017
Yes. The one advantage is that the water baths are usually more precise than the standard convection oven. That may change when some of the new ovens appear with better temperature controls.
 
Bob July 21, 2017
I've used glass jars to make an ice cream base containing eggs, then cooled the mixture and put it in my ice cream maker. I didn't have to worry about raw eggs or curdled ones.
 
Ollie W. July 20, 2017
Very interesting, especially for braises that fill the container. For something like a steak, though, I personally find it too much of a fuss; I use silicone bags, the brand of which shall go unmentioned - reusable, eco-friendly and dishwasher-safe. Anyone have experiences regarding even cooking at higher temperatures considering the higher specific heat capacity of glass?
 
Peter W. July 23, 2017
The glass should eventually reach the temperature of the water bath. It just can change a bit slower than a plastic bag. But it won't exceed the temperature. So you should be able to set the bath for your braising temperature and let the glass pass along the temperature of the water.