Sous Vide: Recipes, Techniques & Equipment (Part 4)

[jackal10]

Does no harm to texture and exceeds the FDA rules (89 mins at 55C/131F, 112mins at 130F).

I don't know the heat/time sensitivity for the bugs likely to be found in scallops, but I believe the FDA regulations are based on 10D reduction of Salmonella and Listeria, so would seem generally safe.

[DouglasBaldwin]

I'm afraid you are mistaken, those pasteurization times correspond to 6.5D reduction in Salmonella but not Listeria monocytogenes. A similar decimal reduction in Listeria at 131F (55C) would take quite a bit longer.

[jackal10]

Can I ask your source?

I was quoting CALCULATING THE TOTAL GROWTH OF BACTERIA IN COOKED FOOD USING THE FDA CODE CONTROLS by O. Peter Snyder, Jr., Ph.D Hospitality Institute of Technology and Management.

Heat Resistance of Salmonella spp., Listeria monocytogenes, Escherichia coli 0157: H7, and Listeria …

CA O'Bryan, PG Crandall, EM Martin, CL Griffis, MG … - Journal of Food Science, 2006 - Blackwell Synergy

Page 1. Vol. 71, Nr. 3, 2006—JOURNAL OF FOOD SCIENCE R23

show a D time of 43.3 mins at 55C for chicken thigh for Salmonella and 38.94 mins for L. monocytogenes, actually less for listeria.

More relevalnt, perhaps is

Journal of Food Protection, Vol. 71, No. 6, 2008, Pages 1287–1308

Supplement

Response to the Questions Posed by the Food and Drug

Administration and the National Marine Fisheries Service

Regarding Determination of Cooking Parameters for

Safe Seafood for Consumers

They give SD values for 10-12 mins for Listeria at 55C, (hence 65-78 mins for 6.5D) but point out that these values are not enough to degrade viruses, such as Hepatatis A if the shellfish has grown in contaminated water, and that the effect on parasites and parasitic protozoa is unknown, although "there is little information to suggest that parasitic protozoa are involved in seafood illnesses"

Edited July 29, 2008 by jackal10 (log)

[DouglasBaldwin]

First off, ``Calculating the Total Growth of Bacteria in Cooked Food Using the FDA Code Controls'' by O.P. Snyder discuss the cold holding of food. Snyder concluded that the FDA regulations seem to correspond to 10 generations of growth (or 2^10 ~ 10^3 increase in either Listeria or Salmonella).

I assumed that the pasteurization temperatures and times you mentioned were from the 2005 US Food Code section 3-401.11.B.2, which does indeed correspond to a 6.5D reduction in Salmonella spp (in beef and pork where D[140°F (60°C)] = 1.73 minutes and z = 10 °F {5.5°C}). In contrast, for Listeria monocytogenes in beef, D[140°F (60°C)] = 8.32 minutes and z = 10.8°F (5.98°C) [J. E. Gaze, G. D. Brown, D. E. Gaskell, and J. G. Banks, ``Heat resistance of Listeria monocytogenes in homogenates of chicken, beef steak and carrot,'' Food Microbiology 6 (1989), 251--259].

I'm afraid I do have access to either the Journal of Food Science or the Journal of Food Protection. I will certainly request those specific articles from my university library though.

[jackal10]

The 2006 review paper is available online at http://www3.interscience.wiley.com/cgi-bin...601213/PDFSTART. You may need ATHENS login, or equivalent if your institution supports it.

I should have cited

Thermal Inactivation of Salmonella and Listeria monocytogenes

in Ground Chicken Thigh/Leg Meat and Skin

RY Murphy, T Osaili, LK Duncan, and JA

Poultry Science, Vol 83, Issue 7, 1218-1225 (2004)

which is online (free) at http://ps.fass.org/cgi/reprint/83/7/1218

The FDA paper (also free) is at http://www.fsis.usda.gov/PDF/NACMCF_JFP_Ma...ipt_07-612R.pdf

I'd still like to know the shelf life (in a refrigerator) of scallops cooked sous vide at 55C for say 2 hours, and left sealed.

Edited July 29, 2008 by jackal10 (log)

[nickrey]

Thought I'd add a cooking comment just to balance the science with a more practical orientation.

I've been cooking sous vide salmon (using nathanm's temperatures and times, thank you) and love the moistness but felt it was missing something in texture.

On opening the sous vide parcel, the skin is easily removed. The first time I did this, I just discarded the skin but felt this was perhaps removing a good part of the fish.

What I've been doing is removing the skin and frying it skin side down first to crisp it up and then turning it over so the fatty side of the skin is on the heat. Like with pork skin, the fat expands and it produces a type of salmon crackling which I then serve over the top of the fish. The crunchiness contrasts with the soft salmon to give a nice eating experience.

Edited July 30, 2008 by nickrey (log)

[DouglasBaldwin]

nickrey,

I do something very similar, except I remove the skin before bagging. I never preformed a double blind tasting, but always felt that cooking with the skin on caused too strong of a fish taste.

Jackal10,

The FDA paper was quite interesting. They also felt that a 6D reduction in Listeria would result in at least a 6D reduction in Salmonella, S. aureus, Campylobacter, and E. coli O157:H7 (see Appendix II). Based on Appendix II, they are using D[63C] = 2.8 min with z = 7.45C for Listeria monocytogenes. This results in the following pasteurization times for a 6D reduction of Listeria in a 131F (55C) water bath:

mm -- HH:MM:SS

5 -- 02:24:50

10 -- 03:26:28

15 -- 03:33:14

20 -- 03:43:01

25 -- 03:54:15

30 -- 04:08:27

35 -- 04:25:43

40 -- 04:44:48

45 -- 05:06:36

50 -- 05:31:25

55 -- 05:58:24

60 -- 06:27:37

65 -- 06:59:08

70 -- 07:32:37

and in a 141F (60.5C) water bath:

mm -- HH:MM:SS

5 -- 00:38:29

10 -- 00:42:27

15 -- 00:49:11

20 -- 00:58:35

25 -- 01:10:37

30 -- 01:24:50

35 -- 01:41:19

40 -- 01:59:40

45 -- 02:19:54

50 -- 02:41:48

55 -- 03:05:17

60 -- 03:30:12

65 -- 03:56:44

70 -- 04:24:51

However, the report felt that Salmonella should be the target organism for inactivation during cooking. They also recommended that the inactivation times provided in the 2005 FDA Food Code (D[140F] = 1.73 min with z = 10F) be used even though they are not based on data for seafood. Thus, the pasteurization times for a 6.5D reduction in Salmonella in a 131F (55C) water bath are:

mm -- HH:MM:SS

5 -- 01:31:10

10 -- 01:34:57

15 -- 01:42:09

20 -- 01:52:24

25 -- 02:04:47

30 -- 02:20:06

35 -- 02:38:34

40 -- 02:59:06

45 -- 03:22:13

50 -- 03:47:59

55 -- 04:15:46

60 -- 04:45:29

65 -- 05:17:15

70 -- 05:50:44

[jackal10]

Thanks. Are these thickness to centre or total thickness?

What value have you taken for thermal transmission?

I would expect the centre of a scallop to be reasonably sterile, but 3 hours would certainly be OK.

How long would you expect 6.5D to hold at say 4C and 20C?

FDA times again? 16 hours at 21C (room temperature) and 7 days at 4C (fridge)

From a processing and restaurant service point of viw I'd prefer to use a 55C bath for longer than a 60C bath. With a 55C there is no danger of any part over-cooking and time (above some minimum) becomes less critical. Thus if the scallops (or fish or lobster or whatever) are bagged and put in the bath at say some time betweeen 3pm and 4pm, they are good for service at any time from 7pm to midnight...

Edited July 30, 2008 by jackal10 (log)

[DouglasBaldwin]

The thickness is the total thickness. As mentioned in my guide, I use thermal diffusivity of 0.956 mm^2/sec in all calculations. I chose this thermal diffusivity to assure (with 98% confidence) that I am not underestimating the temperature of the meat. However, except for thick pieces of meat, a higher thermal diffusivity will not substantially reduce the pasteurization time.

The FDA article mentioned that ``as a general rule, the interior muscle tissue of a healthy live animal harvested from unpolluted waters is sterile'' [pp. 1291]. However, without knowing the provenance of the fish, we should not assume that it is sterile. Moreover, the FDA article states that ``bacterial and viral contamination in finfish is generally assumed to be present on the external surface, whereas in molluscan shellfish and crustaceans contamination may be internalized...'' [pp. 1293].

As for cold holding times, the 2005 Food Code states that food must be discarded if not served within four (4) hours of being removed from temperature control (3-501.19.B). As for cold storage, the 2005 Food Code (3-501.17.A) allows up to 7 days of storage at less than 41F (5C) or up to 4 days at less than 45F (7C). Since the food is being prepared sous vide, the 2005 Food Code (3-502.12.D.2.e) states that:

Except for frozen FOOD that is not shelf life restricted,

cooled to 5°C (41°F) in the PACKAGE or bag as specified

under § 3-501.14 and then cooled to 1°C (34°F) or less

within 48 hours of reaching 5°C (41°F), and:

(i) Held at 1°C (34°F) and consumed or discarded within

30 days after the date of preparation, or

(ii) If removed from a storage unit that maintains a 1°C

(34°F) FOOD temperature, held at 5°C (41°F) or less for

no more than 72 hours before consumption.

All that being said, it would be much easier to hold it in the water bath until it is needed (which is also allowed by the 2005 Food Code {3-501.16.A.1}). While perfectly safe, have you found that the texture is adversely affected by holding in the water bath for that many hours?

[jackal10]

I've not found the texture deteriorates for fish with extended hot hold times, but I would not go above say 12 hours. I think with long hot hold times above this you may get some oxidation that will affect flavour, despite the vacuum packing.

For meat the texture changes as the collagen denatures to gelatin. Although some chefs cook sous vide for 24 or even 48 hours, I personally don't like the texture.

I'd be interested in other's experiences

Edited July 30, 2008 by jackal10 (log)

[DouglasBaldwin]

Jackal10,

I just got the 2006 J. Food Science article by O'Bryan, et al. and found it very useful indeed. For those interested, I have updated my pasteurization tables (4.1--5.2) to reflect these more accurate D and z values. Since the review article had many D and z values at the temperatures we cook at, I took the arithmetic mean of the D and z values.

Since I am no longer extrapolating from much higher temperatures, the 6D Listeria monocytogenes pasteurization times are now inline with the 6.5D (for beef) and 7D (for poultry) Salmonella pasteurization times. So, if you printed off my guide and use the tables frequently, I would recommend printing a new copy and throwing away the old copy.

Edit: Typo

Edited July 31, 2008 by DouglasBaldwin (log)

[DouglasBaldwin]

Also had another question:

In the NYTimes Mag "Under Pressure" article, Bruno Goussault emphasizes the importance of multi-stage cooling, e.g. heating the protein to temp and then having it "cooled, successively, at room temperature, in cold water, then in ice water, before being reheated and served."

Is there some reason for multi-stage cooling? If the point  is simply to get the protein to safe holding temperature, wouldn't ice water get it to that temperature the fastest?

...

←

There is NO point to multi-stage cooling.

If you are going to store the SV product after cooking, then you should cool it to storage temp (very cold - ideally just above freezing) as soon as possible. The best way to do this is to either immerse in ice water, or use a blast freezer (like a convection oven, but with cold air not hot).

...

←

I know I'm quoting a rather old post, but I recently had an interesting discussion with a chef who uses the CS (Cuisine Solutions) system. It seems that the reason for cooling ``successively, at room temperature, in cold water, then in ice water'' is to allow the meat time to absorb some of the liquid in the bag. My initial tests seem to confirm this.

I cooked a batch of pork confit (see my guide). Then I rapidly cooled half the batch in ice water. The other half I cooled for 15 minutes at room temperature, then 15 minutes in cool tap water, then in ice water until cold. After reheating one bag of each, the slowly cooled meat was 2.4%* heavier than the rapidly cooled meat.

* [(MS+FS)/(MS+FS+LS)]/[(MR+FR)/(MR+FR+LR)] - 1 = 2.4%, where M is the weight of the meat, L is the weight of the liquid, F is the weight of the rendered fat, S is for slowly cooled, and R is for rapidly cooled.

Edited August 4, 2008 by DouglasBaldwin (log)

[Vicious Wadd]

Any difference in taste or texture?

BTW, thanks again for the emails regarding my rolled leg of lamb experiment. It came out great. I'll post pics sometime soon.

Currently, I have a "deconstructed osso buco" cooking in a 135 degree water bath. It will be consumed at the 26-27 hour mark this evening.

Best,

- VW

[jackal10]

Col. Kenny Herbert’s Chicken Curry

(Heavily adapted from Culinary Jottings for Madras 1891)

4 generous portions with rice

Spice paste

1 clove garlic

1 tsp/2.5g turmeric

1 tsp/2.5g coriander

1 tsp/2.5g poppy seed

1 tsp/2.5g black pepper

2 chillies (or more, depends how hot they are and how hot you like it)

1 tsp/2.5g sugar

1 tsp/2.5 g salt

1 tsp/2.5g grated green ginger

1 Tbs/15ml oil

Whiz together into a paste

2 peeled and chopped onions softened in 50g/2 oz butter

Stir in spice paste and fry for one minute

Add 10 ml redcurrant jelly, 20ml wine vinegar or lime juice

Add 50ml coconut cream, 50ml chicken stock

I bay leaf

Put into bag with

500g boneless and skinless chicken pieces (can leave bones in thigh)

Seal, cook sousvide at 60C for 3 hours minimum, 12 hours or overnight for preference

Edited August 4, 2008 by jackal10 (log)

[adey73]

sous vide chicken curry!

Make sure the posters on the Indian forum don't see this they'll be after you for being none desi!

have to try it, did the chicken absorb the flavour of the curry broth & did you blow torch the chicken after?

[alwang]

I've not found the texture deteriorates for fish with extended hot hold times, but I would not go above say 12 hours. I think with long hot hold times above this you may get some oxidation that will affect flavour, despite the vacuum packing.

For meat the texture changes as the collagen denatures to gelatin. Although some chefs cook sous vide for 24 or even 48 hours, I personally don't like the texture.

I'd be interested in other's experiences

←

My experience is that the texture of fish deteriorates even with smaller increases of hot holding time, at least at 50C (which is my default temperature for fish). Once you get past 60 minutes, the structure of the fish starts falling apart, and there is a cottony texture, for lack of a better descriptor. I've never tried scallops at these longer cooking times.

[jackal10]

skinless chicken pieces...no searing or blowtorch

[DouglasBaldwin]

the slowly cooled meat was 2.4%* heavier than the rapidly cooled meat.

Any difference in taste or texture?

...

←

I didn't notice a significant difference between the two. But, that doesn't mean there might not be a significant difference in taste or texture in another recipe. Either way, it is certainly interesting and runs counter to one of our long held assumptions.

[MikeTMD]

Does anyone have any opinion, or experience with SV eel? It's a lot more "dense" than most fish, and has a healthy amount of fat - which I would like to render out.

Suggestions, please!

[MikeTMD]

Well, I am happy to answer my own question now:

Yellow River Eel cooked @ 55C for 2.5 hours - perfect results, meat turned out to be very tender, falling off the bone. Skin peeled off quite easily, flesh retained moisture and gelationous texture.

[jackal10]

Another recipe adapted from CUlinay Jottings for Madras By "Wyvern" (Col. Kenny Herbert) 1891.

LAMB QUOORMA

Kenny Herbert ("Wyvern") said:

The QUOORMA, if well made, is undoubtedly an excellent curry. It used, I believe, to be one of the best at the Madras Club, in the days when curries commanded closer attention than they do now....

This, it will be perceived is a curry of rich yet mild description. The total absence of chilli constitutes, in the opinion of many, its chief attraction. "

(JL note: You can add some chopped fresh chilli if you want it hotter, but I would not)

For 4 good portions

Mix:

500g cubed boneless lamb

15g peeled ginger whizzed with 10g salt

Leave to marinate from 2 to 24 hours covered in fridge.

Spice mix (can be made in bulk):

2.5g coriander

2.5g ground Black Pepper

1g ground cloves

2.5g turmeric

2.5g cardamom

Sauce

Soften 2 onions peeled and cut into rings in 50g butter

Add 2 cloves crushed garlic

Add 11g spice mix, fry for 3 mins

Add 125ml light stock or water, simmer for 5 mins

Stir in 200g coconut cream. Let cool.

(For added richness can add 100g crème fraiche or yogurt)

For added heat add 2 sliced green chillis

This sauce can be made in advance, frozen or bagged and sterilised

Assembly and cooking

Bag sauce and lamb. Sous vide for 12hours or more at 58C

Serve with rice and fresh chutneys, dahl, chapatti etc

Tomato chutney:

2 or 3 ripe tomatoes, peeled, seeded and chopped with quarter of their bulk of onion

Season with a bit of salt, two green chillis chopped small, a bit of chopped celery a dust of black pepper and moisten with a teaspoon of vinegar

Cucumber chutney

Cu the cucumber into thin strips and inch long, say two or three heaped tablespoons. Mix with a teaspoonful of chopped spring onion, one of chilli, and one of parsley.

Moisten with a dessert-spoon of vinegar in which a pinch of sugar has been dissolved, a dessertspoon of oil, salt and pepper at discretion

Mint leaves or Mango or Apple Chutney

As cucumber. Apple and Mint is particularly good.

Edited August 10, 2008 by jackal10 (log)

[nickrey]

If anyone wants a copy of Wyvern's Culinary Jottings cookbook, here's a link to an e-version of it.

http://www.archive.org/details/culinaryjottings00kenn

[e_monster]

Has anyone done Tri-Tip sous-vide? Would this be a case where a long-cook would help tenderize it? I find tri-tip to be flavorful but also easy to turn into leather if one grills it too fast.

I would love to hear temp/time from anyone that has had success.

Or, perhaps this is a cut where sous-vide doesn't make a huge difference?

[KennethT]

quick question for anyone who has confit/sous vide experience... I did a bunch of moulard legs confit sous vide at 82.3degC for about 7 hours (experimenting using Paula Wolfert's expert advice regarding salting, etc.)... I tasted one straight out of the circulator and it was very tasty, and then cooled the other couple (bagged separately), and have kept them in the refrigerator (whose temperature is on the cusp of freezing) for quite a while to age - now over a month old...

My question is regarding botulism... would storing standard (non sous vide) confit be considered a reduced oxygen environment? I'd assume so since the meat is surrounded by cold, hard fat... but yet, it can be stored for months without botulism concerns...

Am I risking certain illness by trying some of that confit that eyes me every day? I would assume that there wouldn't have been much bacteria in there to multiply since it was salted for 12 hours (thereby reducing the Aw) and cooked at 180degF for so long thereby pasteurising it...

Also, note that the bags have not changed in appearance at all - no gases inflating the bag, etc... and the fat looks like it is surrounding the meat nicely...

I'd appreciate anyone's thougts on the topic...

Thanks!

[DouglasBaldwin]

To quote my guide:

While keeping the food sealed in plastic pouch prevents recontamination after cooking, spores of Clostridium botulinum, Clostridium perfringens and Bacillus cereus can all survive the mild heat treatment of pasteurization. Therefore, the food must either be served immediately or rapidly cooled and refrigerated at

1. below 36.5°F (2.5°C) for up to 90 days,

2. below 38°F (3.3°C) for less than 31 days,

3. below 41°F (5°C) for less than 10 days, or

4. below 50°F (10°C) for less than 5 days

to prevent non-proteolytic C. botulinum from outgrowing and multiplying to hazardous levels [Pec97].

....

A few sous vide recipes, such as duck, pork and turkey confit, use temperature-time combinations which can reduce non-proteolytic C. botulinum to a safe level; specifically, a 6D reduction in non-proteolytic C. botulinum requires 363 minutes (6 hours and 3 minutes) at 176°F (80°C) or 36 minutes at 185°F (85°C) [Pec97]. The food may then be stored at below 50°F (10°C) indefinitely (the minimum temperature at which proteolytic C. botulinum and C. perfringens can grow). If the food was vacuum sealed using a clamp style vacuum sealer, then there is sufficient air left in the package for B. cereus to grow and the food should be stored at below 39°F (4°C) [RR01].

So, if the bags were kept at `the cusp of freezing' then your duck confit should remain safe indefinitely. (Since if there was any non-proteolytic C. botulinum {which is unlikely, since it is usually only present in fish}, you reduced it to a safe level during cooking.)

Traditionally prepared confits also have botulism concerns, but are also fine if they are stored at below 50F (10C) in a reduced oxygen environment (e.g., covered with fat).