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Sous Vide: Recipes, Techniques & Equipment, 2012


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Thanks for the responses. I've just found out the power was likely to have been out for about an hour, but could have been as long as 3 hours (power was restored to different parts of our neighbourhood at different time, the power company can't provide exact details). I think I'll err on the side of caution this time. Our power is generally very reliable, and I don't cook overnight very often, so this is a pretty rare event.

Edit: Just read DocDougherty's response. Thanks for the info. The core was above 60C for over 16 hours. Maybe I'll reconsider my decision. Thanks.

Thanks again.

Edited by turtleboom (log)
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Hi,

Hopefully someone can help out with a bit of a problem I have. I'm cooking short ribs for 48 hours @60C. When we went to bed at 11pm, the bath was working nicely at 60C. This morning, my wife woke up at 5:30am and discovered that we had a power outage overnight. When she woke up, power had been restored and the sous vide rig was at 60C (I use a Sous Vide Magic and rice cooker - it automatically restarts when power is restored).

We're trying to find out how long the outage was, to estimate how much the water temperature would have dropped during the blackout.

The short ribs had been in the bath for over 24 hours before the power was cut.

How can I tell if they are safe to eat? What temperature can the bath drop too before I have to throw them away?

Thanks.

Turtleboom,

Unless you need to eat them right away, I would chill them, and then measure the temperature drop if you turn off the power, vs. how long you think you were without power.

If the temperature drop over that amount of time was less than 5C, i.e., to less than 55 C, then you are absolutely OK. If it was longer than that, then the question is whether it would drop to below 55C for more than four hours.

Since I suspect that you would have known if the power had gone out for four hours or more, I think you are almost certainly fine.

If not, feel free to inscribe this on your tombstone! :-)

Good luck!

To give you an idea how fast a rice cooker will lose temperature, I show you the diagram of an open loop tuning experiment from blackp (back in 2009 Robert Jueneman and blackp and I conducted experiments to compare different cookers controlled by an SVM):

1500C_Tiger-12L_SET55_P0_openloop-tuning.jpg

This shows you that a well insulated rice cooker may lose in the range of 2.0 - 2.5 °C per hour.

So to drop the temperature from 60°C to 53°C (the upper limit of growth of Clostridium perfringens) it would have taken roughly 3 hours, and if power outage in the worst case had been 6.5 hours (11pm till 5:30am), you were less than 4 hours in the "danger zone".

Edit: I just read that your power outage was 3 hours or less, so you are definitely on the safe side.

Edited by PedroG (log)

Peter F. Gruber aka Pedro

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Has anyone here been using the Zip Loc vacuum bags for long-cook sous vide applications? I've cooked chicken breast, salmon and some tender steak cuts in them with no issues, but those all were 90 minutes or less. I have a piece of skirt steak that I want to try for 24 hours but am a little more apprehensive about trusting the "one-way valve" on the bag for this.

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I've used regular zip locs for 48 hrs with no problems

Thank you, but I'm not talking about the regular zip loc freezer bags (which I've used for 72 hour short ribs and the like), but rather the zip loc vacuum bags that have both a zip seal at the edge and a one way vacuum valve through which you can pump out air. It's that valve that I'm concerned about.

Here's the product page for what I'm talking about

http://www.ziploc.com/Products/Pages/VacuumFreezerSystem.aspx

Edited by Caruso (log)
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Does anyone know what happens to vegetables during long cook times? For reasons that are unimportant to go into right now, I'm cooking potatoes at 170F for 12 hours. What will I get at the end of it? Tender potatoes? Mush?

How did it work out? In my experience you need to cook potatoes at around 82C (180F) to get a palatable outcome. Did the longer cook at a lower temperature give a reasonable result?

Nick Reynolds, aka "nickrey"

"The Internet is full of false information." Plato
My eG Foodblog

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I suppose that SV techniques might make sense for potatoes if you wanted to keep a very specific texture (for example, if you wanted the most firm version of "completely done" you could get). Otherwise, I've had the best results by pressure-steaming potatoes for 5 minutes or so.

--

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I've used regular zip locs for 48 hrs with no problems

Thank you, but I'm not talking about the regular zip loc freezer bags (which I've used for 72 hour short ribs and the like), but rather the zip loc vacuum bags that have both a zip seal at the edge and a one way vacuum valve through which you can pump out air. It's that valve that I'm concerned about.

Here's the product page for what I'm talking about

http://www.ziploc.com/Products/Pages/VacuumFreezerSystem.aspx

I've used these with no problems... if I'm nervous, after sucking the air out, I"ll stick a piece of duct tape over the valve.

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Duct tape - such a simple solution for piece of mind! Thanks. Only downside I suppose is that it might make it harder/impossible to reuse the bags, depending on how they handle having duct tape removed from the valve area, but for big productions probably worth it.

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Does anyone know what happens to vegetables during long cook times? For reasons that are unimportant to go into right now, I'm cooking potatoes at 170F for 12 hours. What will I get at the end of it? Tender potatoes? Mush?

How did it work out? In my experience you need to cook potatoes at around 82C (180F) to get a palatable outcome. Did the longer cook at a lower temperature give a reasonable result?

They turned out firm and slightly gritty. I imagine they would be largely indistinguishable from potatoes cooked for 30 minutes at that temp.

PS: I am a guy.

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I was given a whole salmon the other day, which I have cut up into fillets to prepare sous-vide. I don't really need them all right away, so was wondering if I could freeze them in their packages and cook as normal. Would they survive the freezing without losing texture, and if so, how much longer should they cook than normal?

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I think they will survive freezing just fine, although the FDA doesn't really recommend vacuum packaging of frozen fish unless it was received in a frozen state, and has never been thawed. Personally, I believe that is a CYA attitude to cover commercial users, but check the US Food Code for more details.

As to how much long they would need to cook - that is a difficult question to answer precisely. Douglas Baldwin and MC have some approximation tables, but the computations are technically complex.

What I would do is throw the fish in the bath, and then feel them from time to time. Once they appear to have thawed, you can use the various tables or the Sous Vide Dash app to figure out how much longer to cook them.

As a rough approximation, if you are planning dinner -- I'd add say 5 to 15 minutes, depending on the thickness.

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Thanks, Robert, your reply is pretty much what I was thinking, so I appreciate the corroboration! Just in case my guests do expire as a result of the meal, however, please do forward me your contact information so I can include you in the countersuit ;-)

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SV fish is not cooked to pasteurization temps so the entire food chain pre-cooking is important. I'd try to figure out a way to freeze the fish as rapidly as possible and thaw the fish as rapidly as possible to minimize the proliferation of pathogens.

PS: I am a guy.

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According to FDA’s bad bug book, freezing fish for at least 7 days at or below -20°C/-4°F will kill parasites like Anisakis (but not bacteria), and it should not deteriorate texture significantly; you might eventually freeze before vacuum-sealing if you use vacuum levels as high as the ones produced by chamber machines to avoid deterioration of texture.

When using Douglas Baldwin’s table for heating meat from frozen, add some safety margin, as he used a thermal diffusivity of 1.4×10-7 m2/s in contrast to the thermal diffusivity of 0.995×10-7 m2/s he used in the tables for pasteurizing fish from 5°C. For pasteurizing, first thaw, e.g. in a 0-1°C water pot in the fridge.

Peter F. Gruber aka Pedro

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I cooked some baby octopus yesterday, came out fabulous!

Used T. Keller's time and temp (170.6 degrees, 5 hours).

Bagged the trimmed up critters in some arbequina olive oil, dried oregano, couple of bay leaves, salt and pepper.

After cooking, reserved the cooking liquids and separated the olive oil.

Added the olive oil back to the octopus along with chili flakes, garlic and lemon juice and let it marinate for a couple of hours in the fridge.

Served the baby octo over a bed of shaved fennel, parsley and halved cherry tomatoes. The marinade was the salad dressing.

The octopus was meltingly tender and flavorful.

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As for the freezing of fish - I regularly purchase whole sides of different fish including salmon and portion them, vacuum pack and then freeze them. I find that the texture of the thawed product or that cooked SV from frozen to be almost indistinguishable from the fresh article.

There is one caveat to this though. I get all my fish from a place that supplies top end restaurants. The main reason for this is that they are very careful that all their fish is "dry processed" - that is that once the fish flesh is exposed no water or ice comes into contact with it. If the fish flesh had been wet or even sitting on a bed of ice as is common in fish retailers the flesh tends to absorb water and apart from the potential contamination issue if you freeze that fish the water crystals will break the fish down as it freezes.

So to cut a long story short freezing fresh fish works fine - so long as the fish flesh is kept scrupulously dry.

Regards,

Peter.

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I have 2 pieces of pork cooking at 82c right now for 12 hours. I also have some chicken wings and some chicken thighs that I would like to cook on the mean time. Sous vide dash was helpful with the thighs at this temperature, but is there a way that I could cook the wings as well?

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I have 2 pieces of pork cooking at 82c right now for 12 hours. I also have some chicken wings and some chicken thighs that I would like to cook on the mean time. Sous vide dash was helpful with the thighs at this temperature, but is there a way that I could cook the wings as well?

82C is very high for pork. What cut are you using?

I like chicken wings cooked in a 62C bath for 12 hours, then fried. I tend to do legs and thighs in a 64C bath for 1.5 hours.

Andrew Vaserfirer aka avaserfi

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I have 2 pieces of pork cooking at 82c right now for 12 hours. I also have some chicken wings and some chicken thighs that I would like to cook on the mean time. Sous vide dash was helpful with the thighs at this temperature, but is there a way that I could cook the wings as well?

82C is very high for pork. What cut are you using?

I like chicken wings cooked in a 62C bath for 12 hours, then fried. I tend to do legs and thighs in a 64C bath for 1.5 hours.

Chicken wings at 60C for 24 hours is incredible - you can actually slide the bones out afterwards,making a boneless wing. Just be careful, the meat is really delicate!

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I have 2 pieces of pork cooking at 82c right now for 12 hours. I also have some chicken wings and some chicken thighs that I would like to cook on the mean time. Sous vide dash was helpful with the thighs at this temperature, but is there a way that I could cook the wings as well?

82C is very high for pork. What cut are you using?

I like chicken wings cooked in a 62C bath for 12 hours, then fried. I tend to do legs and thighs in a 64C bath for 1.5 hours.

Its 1 piece from the shoulder and 1 piece of belly.

I wanted to experiment with this: http://egullet.org/p1672174

Keller is doing his at 82.2 for 12h

Edited by Toufas (log)
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I have 2 pieces of pork cooking at 82c right now for 12 hours. I also have some chicken wings and some chicken thighs that I would like to cook on the mean time. Sous vide dash was helpful with the thighs at this temperature, but is there a way that I could cook the wings as well?

82C is very high for pork. What cut are you using?

I like chicken wings cooked in a 62C bath for 12 hours, then fried. I tend to do legs and thighs in a 64C bath for 1.5 hours.

Its 1 piece from the shoulder and 1 piece of belly.

I wanted to experiment with this: http://egullet.org/p1672174

Keller is doing his at 82.2 for 12h

The shoulder has a number of muscles. I probably wouldn't run any as high as 82C, but would adjust temperature depending on which muscle I was using.

I prefer belly done at 60C for 40 hours.

IMG_1101%2520edit%25202%2520edit.jpg

Pork belly confit and rillets. Both were done at 60C for 40 hours. I just whipped the scraps after I squared off the piece of belly.

Andrew Vaserfirer aka avaserfi

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After 12 hours, the belly came out nice but it wasn't a great piece to begin with. I made it into rilettes. The shoulder did not come out good. I am not blaming the method as it is, but the bad butchering (somebody else bought it for me) and that there was a hole at the seal, and there was water inside. I resealed it with some duck fat but it ended up a bit dry. I will probably use it as a base for something else.

Wings are in @ 60c till tomorrow

Now any recommendations for a rolled lamb breast? I've done 85@12h 72@24h, both good but maybe for something closer to medium?

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