Sous Vide cooking. What's that about?

[Fab Foodie]

The oven idea is possible IF you have a fancy oven with very accurate temperature control at the low temps needed, which for most SV cooking is around 60C. SV machines work at very closely controlled temps 0.1C for prof kit, 0.5 to 1C for domestic kit. Ovens cycle +/- several degrees.

I seriously doubt any piece of factory kit can control to this limit of accuracy, let alone domestic machines. It may read to 0.1 but it won't even measure that accurately.

Anyhow, if I wanted to eat Sous-Vide I'd go to an average Restaurant or Hotel with a choice of dishes that seem beyond the capabilities of the 'Chefs' to eat industrially produced food ... I've no desire to fark about doing it at home. I do it for a living. I can cook a perfectly good rare steak with a very hot pan.

 

[swee'pea99]

I seriously doubt any piece of factory kit can control to this limit of accuracy, let alone domestic machines. It may read to 0.1 but it won't even measure that accurately.

Anyhow, if I wanted to eat Sous-Vide I'd go to an average Restaurant or Hotel with a choice of dishes that seem beyond the capabilities of the 'Chefs' to eat industrially produced food ... I've no desire to fark about doing it at home. I do it for a living. I can cook a perfectly good rare steak with a very hot pan.

Have to say I tend to agree on the steaks - I'm mostly intrigued by joints, having quite recently discovered the difference slow-roasting can make to a pork joint. Fish sounds potentially interesting too...salmon, eg, is so much nicer/moister when it hasn't been overcooked - and apparently with SV, you can't.

 

[slowmotion]

I seriously doubt any piece of factory kit can control to this limit of accuracy, let alone domestic machines. It may read to 0.1 but it won't even measure that accurately.

PID temperature controllers, available on Amazon for less than £20 can easily hold a waterbath to within 0.1C of a chosen set-point if you have the facility to input the PID parameters manually. I've made air ovens that hold to within 0.03C, and that's a lot harder than having the thermal mass of water on your side. Sure, the set point displayed on the controller won't be accurate but you can calibrate that out against a reference thermometer.

My guess is that you could have a pretty decent SV set up for about £150, including a vacuum bag sealer.

Vac. bag sealer £40
8 litre slow cooker £35
PID controller £20
Solid State Relay £5
Aquarium air pump as water agitator £10
PT100 control sensor £7
Bits and Bobs £20

I don't know what the steak would taste like but it would be a lot of fun hacking the gadget into shape.

As for browning the meat, I have one of these....
[media]
View: http://www.youtube.com/watch?v=7nA9cKJG8FE
[/media]

 

[slowwww]

+1 for the Sous Vide Supreme

Re standard vacuum sealer vs. chamber sealer, I couldn't justify £6-800 for a chamber sealer for home and so bought a £40 vacuum sealer with the rolls that you cut to length rather than pre-formed bags. To get a similar effect to the chamber sealer, I cut the bags longer than they need to be, put the meat and sauce/flavourings in and then hang the bag off the end of a work surface so all the sauce falls to the bottom. Switch on the vacuum sealer and then as soon as the air is out and the sauce is rushing to the top of the bag, hit the manual seal button.
The meat is not fully under vacuum, but for cuts like brisket or skirt, but I think the benefit of being cooked in the sauce overrides this.

At the risk of antagonising 3BM and his bollocks further, Polyscience Smoking Gun anybody? I'm contemplating it but don't know anyone who's used one.

 

[Fab Foodie]

PID temperature controllers, available on Amazon for less than £20 can easily hold a waterbath to within 0.1C of a chosen set-point if you have the facility to input the PID parameters manually. I've made air ovens that hold to within 0.03C, and that's a lot harder than having the thermal mass of water on your side. Sure, the set point displayed on the controller won't be accurate but you can calibrate that out against a reference thermometer.

My guess is that you could have a pretty decent SV set up for about £150, including a vacuum bag sealer.

Vac. bag sealer £40
8 litre slow cooker £35
PID controller £20
Solid State Relay £5
Aquarium air pump as water agitator £10
PT100 control sensor £7
Bits and Bobs £20

I don't know what the steak would taste like but it would be a lot of fun hacking the gadget into shape.

As for browning the meat, I have one of these....
[media]
View: http://www.youtube.com/watch?v=7nA9cKJG8FE
[/media]

What's the tolerance of a PT100? I really struggle to believe that level of accuracy is possible, though I bow to your greater experience!

 

[Fab Foodie]

Have to say I tend to agree on the steaks - I'm mostly intrigued by joints, having quite recently discovered the difference slow-roasting can make to a pork joint. Fish sounds potentially interesting too...salmon, eg, is so much nicer/moister when it hasn't been overcooked - and apparently with SV, you can't.

Do t get me wrong, SV is a great technology that's been around industrially IIRC 20 odd years or so from memory. It means I get can get great food at average eating establishments and probably most chain hotels I stay in. There are also great high quality SV products in the supermarkets too. I guess it's not something I want to do at home.

 

[PK99]

Have to say I tend to agree on the steaks - I'm mostly intrigued by joints, having quite recently discovered the difference slow-roasting can make to a pork joint. Fish sounds potentially interesting too...salmon, eg, is so much nicer/moister when it hasn't been overcooked - and apparently with SV, you can't.

Fish is different..... With meat you are trying to do two things, for tender cuts you are looking to just cook to the right temperature and within reason you can hold for some considerable time. An hour or so beyond target temp is no problem. With tough cuts, you are looking to break down the collagen, that takes a long time and there is little difference between 36 and 48 hours.

With fish however you are simply seeking to set the proteins. With say, salmon, there are a range of temperatures that produce markedly different results, but at any of them holding for too long turns the fish to mush. 5/10 mins on a 30 minute cook can be significant. Unlike say lamb which is great medium rare but equally good well done as in Gigot de Sept Heures.

But SV salmon is fantastic.ditto cod.

 

[PK99]

+1 for the Sous Vide Supreme

Re standard vacuum sealer vs. chamber sealer, I couldn't justify £6-800 for a chamber sealer for home and so bought a £40 vacuum sealer with the rolls that you cut to length rather than pre-formed bags. To get a similar effect to the chamber sealer, I cut the bags longer than they need to be, put the meat and sauce/flavourings in and then hang the bag off the end of a work surface so all the sauce falls to the bottom. Switch on the vacuum sealer and then as soon as the air is out and the sauce is rushing to the top of the bag, hit the manual seal button.
The meat is not fully under vacuum, but for cuts like brisket or skirt, but I think the benefit of being cooked in the sauce overrides this.

At the risk of antagonising 3BM and his bollocks further, Polyscience Smoking Gun anybody? I'm contemplating it but don't know anyone who's used one.

Nice tip re the searing for liquids.... I will try that. In some cases I have frozen the whole bag before sealing.

I too am tempted by the smoke gun.... My wife is horrified by the geekiness!

 

[slowmotion]

Oh no, its all gone technogeeky

Sorry. I can't help it.

 

[slowmotion]

What's the tolerance of a PT100? I really struggle to believe that level of accuracy is possible, though I bow to your greater experience!

<geek mode on>
It depends how much you want to spend.
http://www.omega.co.uk/temperature/pdf/pt100_tolerance.pdf
You don't need a high accuracy PT100 as a control sensor. A £4 Class B will do. All you are trying to do is hold the temperature steady. In order to set the temperature accurately you use a reference thermometer like a Heraeus and calibrate out any offset. It's a quartz crystal oscillator which has a linear temperature coefficient and has an absolute accuracy of 0.02C or better. Ours was calibrated by the National Physical Laboratory so it's probably OK for cooking steak.
<geek mode off>

 

[Fab Foodie]

Remind me to ask you what it is you do sometime. I shall look forward to not understanding the answer.

That'll make 2 of us then!

 

[AndyRM]

<geek mode on>
It depends how much you want to spend.
http://www.omega.co.uk/temperature/pdf/pt100_tolerance.pdf
You don't need a high accuracy PT100 as a control sensor. A £4 Class B will do. All you are trying to do is hold the temperature steady. In order to set the temperature accurately you use a reference thermometer like a Heraeus and calibrate out any offset. It's a quartz crystal oscillator which has a linear temperature coefficient and has an absolute accuracy of 0.02C or better. Ours was calibrated by the National Physical Laboratory so it's probably OK for cooking steak.
<geek mode off>

Some geek you are if you've not used correct HTML tags

 

[slowmotion]

This guy has just the right attitude to cooking...
[media]
View: http://www.youtube.com/watch?v=16aLzIRHycw
[/media]

Deep joy...geek heaven...

 

[vernon]

This guy has just the right attitude to cooking...
[media]
View: http://www.youtube.com/watch?v=16aLzIRHycw
[/media]

Deep joy...geek heaven...

Ooohhh, I'm coming over all funny

That was a rehash of a chem eng/control engineering lecture that I attended in my second year at Leeds University. I wouldn't have had to do a re-sit if the course had been taught through the medium of food instead of fractionating columns and heat exchangers.

 

[slowmotion]

I have been on ebay and Amazon. Total expenditure so far about £17. A £5 PT100 temperature sensor, a £5 solid state relay, and a £7 1500 watt immersion heater that looks absolutely deadly but should make the system pretty fast-response.
This is fun.

Look at this beauty.
http://www.amazon.co.uk/Immersion-H...59321&sr=8-1&keywords=1500+w+immersion+heater