The transference conjecture

November 8, 2011 8:08 AM

I'm curious if cooking sous-vide could improve on being lazy and well fed, but discussing the technique with my gf she asked reasonable questions I can't find the answer to.

Specifically, she wondered if it's not possible to use a water bath in the oven to achieve the same effect (it seems to be, only less convenient) or why not forgo the water bath and just use a grill bag — such as these — and pop the thing into the oven at low temperature?

I'm not sure about the latter scenario. My oven goes down to 50°C which seems usable for some sous-vide cooking, but I have a feeling that it's the difference between convection and radiation that makes the difference. Am I an the right track? Also, would a convection oven work better, and would it be good enough for sous-vide-style cooking?

For what it's worth, in my specifik case I'd only be cooking vegan food so the practicality of running the oven for 72h ribs is less important than getting crisp asparagus.

posted by monocultured to food & drink (21 answers total)

It's a lot less work to cook veggies in a pan than it is to rig some rube goldberg sous vide setup to poach asparagus.
posted by foodgeek at 8:10 AM on November 8, 2011 [4 favorites]

Sous-vide cooking is an open invitation to horrible, horrible D&V bugs if you get the temperature just a little bit wrong as I understand things.

Hence the importance of an accurate thermometer & a water bath that can consistently maintain the appropriate temperature. I guess if you have a decent oven thermometer you could stick it in a water bath in your oven & check it every ten minutes or so, adjusting the oven as necessary but that sounds like a lot of hassle to me.
posted by pharm at 8:12 AM on November 8, 2011 [1 favorite]

Sous-vide is not going to get you crisp asparagus. Never. Sous-vide, for meat eaters, gets the steak up to the perfect med-rare throughout, but it still needs to be thrown on the flattop for color on the outside. You want the exact opposite: high heat for a short time. Roasted veg >> slow-cooked veg.

Beyond that, ovens cycle too widely, or at least much wider than purpose-built sous-vide contraptions. They're also much less accurate in their temperature readings, especially at the low end.
posted by supercres at 8:17 AM on November 8, 2011

Sorry if this is a derail, but...

While it isn't as flexible as sous-vide, a slow cooker/crock pot is a lot easier to deal with. If your main issue is that you're too lazy to spend time cooking, then I suggest getting a good slow cooker recipe book and going to town. I've got this book, and it's great because the recipes are super simple (as the title suggests, they have only 5 ingredients each) and there is a wide range of things, from soups and appetizers to entrees, desserts, and even a few alcoholic drinks.

This will be easier than rigging up a homemade water bath and they is more room for error.
posted by asnider at 8:19 AM on November 8, 2011 [4 favorites]

If your oven can keep a constant temp (it probably does not keep it that close, but you should check. Ovens cycle pretty widely) then yes, a bag in a water bath in the oven would work.

That said as a vegan? No this is a waste of your time. veggies sous-vide aren't so good, and don't take very long to cook well via traditional methods. The one interesting thing for veg is playing with texture via a chamber vacuum sealer, but those are quite expensive.
posted by JPD at 8:21 AM on November 8, 2011

*there* is more room for error
posted by asnider at 8:23 AM on November 8, 2011

Ok, so using asparagus as an example was a poor choice, but I was thinking more about consistant results rather than a gathering and/or party in my mouth. But the theme seems to be that vegan food doesn't benefit greatly from the technique. Noted and I'll bump this down my priority list.

I'm still curious what the difference is between using a grill bag without water bath in a regular or convection oven, versus sous-vide cooking in water. Is it as simple as temperature control at low ranges?

(I've heard the term "crock pot" put never looked it up. It's not a common appliance here; It looks like a rice cooker though, and I have one of those and use it for lazy cooking occasionally, same idea?)
posted by monocultured at 8:30 AM on November 8, 2011

Maybe you could use this hack? Frankly, it sounds like WAY more trouble than it's worth for vegetables, though.
posted by WorkingMyWayHome at 8:30 AM on November 8, 2011

the difference between a grill bag and proper sous-vide - is as you stated the difference between conduction and radiation. Additionally water has more thermal mass so its easier to control temp.

A crockpot is like a really simple underpowered rice cooker. They can just barely reach a boil, but can hold very low temps for hours. They usually have a heavy ceramic insert for thermal mass and meant to be used for stews and other liquidy dishes.
posted by JPD at 8:35 AM on November 8, 2011

er not conduction and radiation so much as heat transfer via water vs heat transfer via air
posted by JPD at 8:36 AM on November 8, 2011

Minor differences in crockpot and rice cooker would most likely be that the rice cooker has some predetermined setting calculated on cold water/rice being cooked through and then shifting to 'warm' setting (I too have used rice cooker rather than crockpot but seen it used for stews adn soups and casseroles etc) while a crockpot permits setting number of hours to 'cook' like 6 or 8 or whatever

Crockpot or Rice Cooker Best for Sous Vide?
posted by infini at 8:38 AM on November 8, 2011

This is an old thread about finding a crock pot in Sweden but there's some links toward the end that might be helpful.

But I don't think it's necessarily the thing you need. Like sous vide, a slow cooker is largely for proteins that can stand a long run.
posted by Lyn Never at 8:42 AM on November 8, 2011

Agreed that the cycling off and on of a low oven would cause too many dips in the temp. Water would hold it's temp far better. I've not heard of people making sous vide setups in ovens, but I have heard of crock pots with temperature regulators and even insulated coolers filled with hot water and refilled every few hours.
posted by Gilbert at 8:55 AM on November 8, 2011

Asparagus?

Microwave.
posted by flabdablet at 9:09 AM on November 8, 2011

Asparagus? Poach in 2 inches water, drain, drizzle olive oil, salt and roast in 350 oven for 1/2 hour.
posted by thinkpiece at 9:16 AM on November 8, 2011 [1 favorite]

Asparagus? Drizzle with olive oil; Salt, pepper; Throw them on the grill.
posted by banshee at 9:32 AM on November 8, 2011 [1 favorite]

Asparagus: just boiled and dipped in butter sauce, as it should be
posted by infini at 9:39 AM on November 8, 2011

I always steam asparagus, which is easy as hell and lets you pick exactly how crisp you want it.
posted by Ignatius J. Reilly at 9:57 AM on November 8, 2011

IME, sous vide provides little to no benefit for vegetables. Seafood and meat is where it's at.
posted by wongcorgi at 11:29 AM on November 8, 2011

I own a Sous Vide Supreme. The reason it's so fancy and expensive is that it can hold water at a specific temperature, to the nearest 1 degree F (0.5C). Meat and eggs change texture based on exact temperatures of when proteins denature, so precise control like that is valuable. I can't imagine how a sous vide cooker would be very useful to preparing most vegan meals.

There are various do-it-yourself sous video cooker options. A styrofoam container for the water + an immersion heater and thermometer is the basic setup, or a modified crockpot. The key thing is switching the heat source off and on in response to very precise temperature readings. A traditional oven thermostat or crockpot isn't going to do it.
posted by Nelson at 5:39 PM on November 8, 2011

a slow cooker is largely for proteins that can stand a long run.

True, but I've made plenty of vegetarian (though not necessarily vegan) dishes in a slow cooker. Stews, soups, and chilis tend to do the best when cooking veg in a slow cooker, but it is possible to make a good vegetarian meal that doesn't turn to mush.
posted by asnider at 7:39 AM on November 9, 2011