Robert Jueneman
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Posts posted by Robert Jueneman
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Has anyone outside of the MC staff prepared their starch infused French fries using an ultra-sonic bath?
I've ordered a Branson B5510DTH 2.5 gal ultrasonic cleaner and a perforated tray, and am currently waiting for it to arrive. It was about half the price of the one used in MC, and should certainly be large enough. Too bad it won't be here in time for the SuperBowl!
Meanwhile, I thought I'd ask if anyone had some particular tips. I assume the fluid used for the ultrasonic fries (which are sealed in a SV bag) is just water?
I've done Heston Blumenthal's triple-cooked Pont Neuf fries a couple of times. Next time, I will probably use the dehydrator/dryer function on my JennAir oven, rather than risk getting a lot of water vapor into the oil of my chamber vacuum.
Any other advice?
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Those of you who are interested in preparing stocks in a pressure, and particularly large quantities, and especially those who liv at higher altitudes, might be interested in my article, High Altitude Pressure Cooking and Stock Making, at http://freshmealssolutions.com/index.php?option=com_k2&view=item&id=71:high-altitude-pressure-cooking-and-stock-making&Itemid=100088. I t describes how I modified at 27-liter non-electric All-American Sterilizer 1925X made by Wisconsin Aluminum Foundry (WAFCO) for this purpose, and added a PID controller to control the temperature/pressure in combination with an electric griddle.
This is a non-venting unit with an actual pressure gauge on it. It is widely used by dentists, tattoo artists, etc. The pressure gauge is rated at 3%-2%-3%, which means 3% of the full span in the first and last quarters of the dial, and 2% for the middle 50% of the dial. The pressure relieve value releases pressure at 22 psi (+/-1 psi).
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The enzymatic tenderization of meat (muscle, not collagen) is at its peak at around 48-50C. So try cooking chuck for four hours at that temperature, then increase it to 55C and hold it there for another 20 hours or even longer, up to 48 hours, in order to both pasteurize it and gelatinize the collagen.
Isn't it dangerous to keep the meat for four hours at the ideal temperature for enzymatic pasteurization? I'm trying to get a handle on all this so I may be totally wrong, but I thought that keeping it at 48-50 C was inadvisable due to bacteria, and that over 130:F (~54.5 C) was ideal for safety concerns.
I have to say that 131F for 24 hours came out amazing, although it did take a bit of getting used to seeing that greenish hue to the exterior before searing. Once seared, though, it looked great and the taste was perfection.
The general rule is that food should be kept within the "danger zone" of 5C to 55C for no more than four hours. So cooking at an intermediate temperature for four hours, then raising it to the pasteurization temperature of 54.4C/130F or higher for a minimum of 112 minutes should be OK.
The rule for raw or undercooked whole-muscle, intact beef steak is that it may be served to a population that is not a highly susceptible population, and the steak is cooked (i.e., seared) on both the top and bottom to a surface temperature of 63C/145F and a cooked color change is achieved on all external surfaces.
For further (very detailed) reading, see the US Food Code at http://www.fda.gov/Food/FoodSafety/RetailFoodProtection/FoodCode/FoodCode2009/ucm186451.htm#part3-6.
Section 3-401.11 deals with raw animal foods, 3-402.11 deals with parasite destruction in fish, 3-501.14 deals with cooling (within 2 hours from 57C/135F to 21C/70F, and six hours total from 57C to 5C), section 3-502.12 deals with Clostridium botulinum and Listeria monocytogenes in reduced oxygen packaging (i.e., vacuum sealed).
Parts C and D of section 3-502.12 deals with cook/chill and sous vide preparations, and are particular interesting:
C) Except for fish that is frozen before, during, and after packaging, a food establishment may not package fish using a reduced oxygen packaging method. P
D) Except as specified under ¶ © of this section, a food establishment that packages food using a cook-chill or sous vide process shall:
(1) Implement a HACCP plan that contains the information as specified under ¶ 8-201.14(D); Pf
(2) Ensure the food is:
(a) Prepared and consumed on the premises, or prepared and consumed off the premises but within the same business entity with no distribution or sale of the packaged product to another business entity or the consumer, Pf
(b) Cooked to heat all parts of the food to a temperature and for a time as specified under § 3-401.11, P
© Protected from contamination before and after cooking as specified under Parts 3-3 and 3-4, P
(d) Placed in a package with an oxygen barrier and sealed before cooking, or placed in a package and sealed immediately after cooking and before reaching a temperature below 57°C (135°F), P
(e) Cooled to 5°C (41°F) in the sealed package or bag as specified under § 3-501.14 and subsequently: P
(i) Cooled to 1°C (34°F) within 48 hours of reaching 5°C (41°F) and held at that temperature until consumed or discarded within 30 days after the date of packaging;P
(ii) Cooled to 1°C (34°F) within 48 hours of reaching 5°C (41°F), removed from refrigeration equipment that maintains a 1°C (34°F) food temperature and then held at 5°C (41°F) or less for no more than 72 hours, at which time the food must be consumed or discarded; P
(iii) Cooled to 3°C (38°F) or less within 24 hours of reaching 5°C (41°F) and held there for no more than 72 hours from packaging, at which time the food must be consumed or discarded; P or
(iv) Held frozen with no shelf life restriction while frozen until consumed or used. P
(f) Held in a refrigeration unit that is equipped with an electronic system that continuously monitors time and temperature and is visually examined for proper operation twice daily, Pf
(g) If transported off-site to a satellite location of the same business entity, equipped with verifiable electronic monitoring devices to ensure that times and temperatures are monitored during transportation, Pf and
(h) Labeled with the product name and the date packaged;Pf and
(3) Maintain the records required to confirm that cooling and cold holding refrigeration time/temperature parameters are required as part of the HACCP plan and:
(a) Make such records available to the regulatory authority upon request, Pf and
(b) Hold such records for at least 6 months; Pf and
(4) Implement written operational procedures as specified under Subparagraph (B)(5) of this section and a training program as specified under Subparagraph (B)(6) of this section.Pf
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The enzymatic tenderization of meat (muscle, not collagen) is at its peak at around 48-50C. So try cooking chuck for four hours at that temperature, then increase it to 55C and hold it there for another 20 hours or even longer, up to 48 hours, in order to both pasteurize it and gelatinize the collagen.
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One last thing -- you said the pork belly ended up puffing up; like a balloon. I'm assuming you meant the bag puffed up, and not the meat itself?
Yep, the bag. It's become second nature for me to double-seal both edges and I'm really glad I did! The bag was so tight I was worried it would pop just by being touched, but it held together and I could only detect the very faintest smell. But that was enough to know it was bad...
It also occurred to me that maybe the apple juice I used fermented, possibly given a helping hand by the slug of cheap & cheerful sherry I also added.
But despite the disappointment it has been a very valuable learning experience and I really appreciate your input.
Cheers.
I hadn't thought about the apple juice fermenting, nor the alcohol that PedroG commented on, so those were useful inputs.
In retrospect (i.e., water under the bridge), I really wish that you had opened the bag to see what it smelled like. I would think that spoilage bacteria might be one thing, fermented apple juice another, and alcohol yet another.
"The only way to avoid making mistakes is through experience. Unfortunately, the only way to gain experience is by making mistakes!"
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Anyone use their SousVide a lot more than they thought they would? My SVS no longer travels from my countertop to the cabinet it was originally supposed to be stored in. It is now a permanent fixture on my countertop and probably gets used every other day. For better or worse, I use my SVS for probably about 80% of my cooking. I don't think I intended it to be that way, I think the quality of the end result + the convenience of "cook-chill-freeze-reheat" has simply been too much to deny. The SVS with the combination of a good vacuum sealer (I use the VacMaster VP112) has really changed much of my approach to most of my meals.
Anyone else chime in on this?
Todd in Chicago
I'm real new to this but find I am using it A LOT too. I bought an external sealer and have been using ziplocs for marinated meats. That Vacmaster VP112 has been calling out to me, but how heavy/unwieldy is it? Do you find that you really have to leave it out? I wish I had enough counter space for that, but....
Just wait -- it gets worse!
I've been doing this for about four years, now, and I have two immersion circulators in use every day, and sometimes three, depending on what I'm cooking -- and that's just for the two of us! And I recently upgraded my MVS-31X chamber vacuum to the new PolyScience MV-35XP, so at present on my island countertop I have two chamber vacuums, a bottle of gaseous nitrogen for the gas fill, an Anti-Griddle, and I just ordered an Branson ultrasound unit to make starch-infused French fries. So don't complain about counter space!
(BTW, if anyone lives within 150 miles of Taos, NM and needs a chamber vacuum, I'll make you a deal on my MVS-31X. Just PM me.)
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Its unclear to me that there is much to be gained from making meat stock using low temperature sous vide techniques. Quite the opposite, really. There is plenty to be gained from using high temperature techniques (i.e., pressure cooking). The only time it makes sense to use LT/LT sous vide techniques is when making a stock or broth where higher temperatures would be detrimental (i.e., kombu broth, certain vegetable stocks, etc.).
As I mentioned, the main reasoning behind it is more because I don't own a pressure cooker or a very large stockpot. I don't really expect any benefits from using the PID controller.
You might like to look at an article I posted on PID control of a pressure cooker for high altitude pressure cooking and stock making, at http://freshmealssolutions.com/index.php?option=com_k2&view=item&id=71:high-altitude-pressure-cooking-and-stock-making&Itemid=10088.
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I had my first sous vide fail today, which has given me a bit of thinking to do. I've always thought I was pretty careful with hygiene but a pork belly that was in the bath for 3 days ended up puffing up like a balloon, and I have no doubt that if the bag had burst the smell would have been horrid.
I've made several pork bellies before and they've been great, I thought I had my technique down pat. I'm trying to figure out where the meat got contaminated and why it wasn't pasteurised. I'm wondering if it was during the brining? I use an equilibrium brine (from MC, 3.168) and leave the meat in there for a few days. The other potential culprits are the flavourings I added - the only ones I can definitely remember adding are sherry, soy sauce and apple juice, but I might have thrown a few herbs in there too.
This is what I've been doing:
- Firstly I measure out the brine solution. I don't boil the brine or otherwise pasteurise it (which might be a mistake).
- I blanch the meat in boiling water. I've mentioned on the forum before that I copy the
.- I leave the meat to brine for a few days (in the fridge). I always use the weaker equilibrium brine (total concentration of 1% salt, .4% sugar) - not sure if this would help or hinder any bacteria.
- Then I sear the meat on all sides in a hot pan. Again - I would assume that this kills any surface bacteria.
- It's into a vacuum bag with a small amount of flavourings, and cooked for 3 days (72 hours) at 58 degrees C.
I've done a number of pork bellies this way and they've all been awesome- they've all been pretty small, around 500g, so it's not like I have a huge chunk of meat that takes hours to come up to temperature. I was really shocked to see the bloated bag this morning, especially as I think it only started to blow up 2 days into the cooking. I have two digital thermometers that agree with the temperature of the water bath (just a simple rice cooker / temp controller combo), so although it's a budget setup it's accurate. I don't think it's a true PID but the temperature swings are only about 1 degree either way- basically I'm not worried about a problem with my rig.
The main things that worries me is that I thought that 58 degrees would be hot enough to pasteurise the meat but I'm obviously wrong, and also that I didn't see anything wrong for 2 days. I'd like to think that if I got hungry after 48 hours instead of waiting for 72 I would've noticed a bad smell, but I hate the thought of eating something unsafe.
Here's some of my thoughts -
- I should boil the brine (and cool it) before soaking the meat in it.
- I should blanch the meat again after brining.
- any flavourings that I add to the bag should also be boiled & cooled first.
How have others reacted to results that are obviously unsafe to eat?
I'd appreciate any input and advice on what could have gone wrong or what I can do better...
-Chris
Chris, I'm not an expert in food safety, but here is my understanding. Maybe Douglas Baldwin can add something.
First of all, 58C is certainly enough to pasteurize the meat. 55C is enough, assuming an accurate thermometer. But although pasteurization kills all of the potentially deadly pathogens, my understanding is that it doesn't necessarily kill all SPOILAGE bacteria! So even if the bag swelled up, and smelled absolutely horrible, it wouldn't necessarily have been unsafe to eat, although I don't think any of us would be brave enough to find out. (BTW, I had a similar problem once with beef cheeks.)
Now, where could any spoilage bacteria have come from?
Well, potentially it could have come from the pork belly itself. There is a lot we don't know about the sterility of the interior of meat -- it is generally assumed to be sterile, but if the animal was sick, or a dirty knife was used to slaughter it, some nasties could have potentially gotten in the blood and circulated, however briefly. It obviously doesn't happen often.
The brining step is another possibility, especially if you added dry spices that haven't been pasteurized. So adding all of the ingredients to the brine and then boiling it before using it would be a good precaution.
You are already being quite conservative, with the blanching, and then the pre-searing. I would have certainly thought that the searing would be sufficient to kill even any spoilage bacteria, UNLESS the brining carried it deeper into the meat, somehow.
Leaving the meat in the brine for several days seems somewhat suspect, to me. Is such a long time really necessary? I'm assuming it was just sitting in a pan, as opposed to having been bagged, so it's possible that some spoilage bacteria might have been circulating in your fridge.
Did you chill the meat after searing it, before bagging it? If not, the hot juices could cause the bag to swell, at least enough to float.
Finally, although you say that you are comfortable with your SV setup, I've seen temperature probes fail, even on commercial rigs. I would suggest that your fire it up and check the temperature, and if you can stand to let it go for 72 hours, check it again.
One last thing -- you said the pork belly ended up puffing up; like a balloon. I'm assuming you meant the bag puffed up, and not the meat itself?
Bob
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According to http://sousvide.wikia.com/wiki/Find_out_how_strong_a_vacuum_your_machine_produces, a boiling point of 7.1C (about 0.4C lower than I tested), corresponds to a vapor pressure of 10 mbar, or 99.0%, as opposed to the 2 mbar that Busch claims.
Now, is a 99.0% vacuum all that terrible? No, not for most applications, I think. However, if it is an indication that something is wrong, or at least less than optimum, that is a different matter.
I suspect that it indicates that the exhaust filter is clogged with oil, and should be replaced.
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Busch is premier vac pump manufacturer, so that's what you want anyway.
Google "Chamber Vacuum Pump shipped without oil" or "Vacuum pump shipped no oil" and you'll see that universaly, oil vacuum pumps are drained before shipping.
At the very least, I'd insist on the warranty being extended, in writing.
My understanding is that PolyScience has repeatedly requested MiniPack to ship units without oil in them, as the MVS-31X was. All I can imagine is that perhaps MiniPack is trying to save the consumer a bit of an initial headache. The Busch Installation and Operations manual make it very clear that the vacuum pump should not be lifted, much less shipped, when full of oil.
The unit seems to be working OK for now -- at least it is no longer spraying oil all over everything, and it doesn't appear that anything is broken. However, trying to boil chilled water indicates that I am far from the 2 mbar absolute vacuum the pump should be capable of. 11C boils just fine, 5C won't boil, and 7.5C seems to just simmer.
With a 2 mbar vacuum, it should be capable of boiling at 0C.
I suspect that the exhaust filter is oil-soaked, and in addition the fact that the sight glass doesn't line up with the hole in the back indicates some possible freight damage -- maybe the unit got tipped over, somehow, and the pump slid a bit.
I want to make it very clear that I am not blaming PolyScience in the least, as they have been very helpful and supportive. If the problem was due to shipping damage, they ought to file a claim against FedEx.
But rather than go through the hassle of returning the unit, I have suggested that they send me a new exhaust filter, and we'll see if that solves the problem.
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I took the back off of the MV-35XP and checked the pump label. First of all, the pump manufacturer is Busch, not Bosch. The type is a KB 0010E 3Z0, which according to the label and the manual, should be able to reach an absolute pressure of 2 hPa (=mbar). So that gives me something that I can test with the water boiling method. If it won't get close to 2 mbar, I will request a new exhaust filter and seal.
PolyScience is sending me the liquid tray, which was supposed to have been included. And they are working with MiniPack in California, to try to resolve some of the other issues.
Bob
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My kit is here and its already cooking my first batch of chicken thighs!
Would the sv dash cooking time be different with more bags of chicken inside vengroff?
As long as water circulates around each bag the cooking time is the same regardless of the number of bags.
That's true, assuming the water bath temperature remains constant.
Obviously, if you throw six bags of cold chicken in a small pot, the temperature of the bath will decrease, and then it is a question of how quickly the water bath reheats.
A good rule of thumb is that the amount of water should be on the order of six times the volume of the food you are cooking.
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Vengroff, the new Sous Vide Dash 3.0 looks fantastic!
When will it be available, and can I help beta test it for you?
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My MV-35XP chamber vacuum arrived a couple of days ago. It is made by MiniPack-Torre in Italy, and is sold exclusively by PolyScience or a PolyScience dealer. There is no online user manual, and the description on the PolyScience website is rather terse, so I thought I would provide some details about its features and operation. I will compare it to the MVS-31X that I've had for a year or more.
Because the single biggest difference between X models and the XP models is the label printer, let me begin by describing what you can include in a label.
The first line is the manufacturer, restaurant name, or owner's name. The second line contains the primary description. The third line is the most flexible and it can contain the ingredients, and you can modify that to say anything you want — there is about six lines available.
The next line is a packaging date and time, followed by an expiration date, the operator’s code or initials, a batch number, and item number within the batch, and then the percentage of vacuum and the percentage of gas, to comply with applicable HAACP regulations. So in my case a sample label looks like this:
****************************
R. Jueneman
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Beef
Rib-eye 35mm 1:37@52.0°C
Pack.: 01/26/2012 11:20
Exp.: 01/26/2013
Op.: RRJ0
Batch: AA0000
Num.: 0004
Vacuum: 100.0% Gas: 00%
****************************
Now, this may be fine for a restaurant, but if you were operating a grocery store or butcher shop, it probably doesn’t go far enough. In particular there is no provision for a bar code, everything is in the same typeface and font size, and for many ingredients there may not be a sufficient amount of space.
Some of the more typical types of products and ingredients are available under the menu selection, but you can still edit the “ingredients” as you wish, one character at a time.
I had hoped that the unit had 100 programs available, but this was apparently a misunderstanding on my part. Only ten programs are available, but for each program you can alter the percentage of vacuum, extra time, gas fill, and the item description. I'll probably keep one program for just generic applications, and develop others for steaks, chicken breasts, corn on the cob, and other vegetables—the things I cook most often.
My understanding is that PolyScience is working with MiniPack, and hopefully they will be able to come up with an interface that is little bit more user-friendly, one that is computer-based, and can offer more extensive features. Hopefully it will be possible to obtain a retrofit kit to update my current unit.
Now, on to the rest of the features:
The interior chamber of the MV-35XP is very similar to that of the 31X, and the seal bar is interchangeable between the two machines. However I was pleased to find that the seal bar that came with the 35XP had a 4 mm seal strip, and a cut off wire, as opposed to the two 3mm strips on my 31X. I find the cutoff wire to be very convenient. If you slop a little bit of food near the edge, the cutoff strip allows you to peel off that portion very neatly, so that it doesn't contaminate your sous vide circulator or whatever.
The overall size of the unit is somewhat larger than the 31X, but that is probably because it uses a Bosch pump instead of the DVP that the 31X uses. It is actually lighter than the 31X.
Unlike the 31X, which has a start button on the front panel, the 35XP starts when you close the lid. Now this might be very handy if you were bagging lots and lots of product at one time, but in my case is a bit of a nuisance, because I have to turn off the machine before I can close the lid just for sanitary reasons.
The 35XP has a soft air release with four different settings, and a gas-fill option at extra cost. I'm in the process of ordering that, because I like that feature on the 31X.
The 35XP also has provision for an external vacuum hose. I had been given to understand that the new unit used a ¼” NPT-thread that you could screw in a hose barb, however, I can only get about one or maybe two threads with my existing barb, so perhaps it is some kind of a metric thread—TBD. If you're using the external vacuum hose, you have to set a parameter on the menu so that you can select START, instead of closing the lid.
The unit was shipped on a wooden pallet, but FedEx refused to bring the unit into the house, despite charging me an extra ninety dollars for residential delivery! Upon unpacking it, I was surprised to see a significant amount of oil in the chamber—perhaps 15ml. It is not clear where this came from, and I am surprised that they shipped it with oil in it. As it was I spent an hour or more running it on the conditioning program, and wiping out the chamber after each use. Somehow oil was being sprayed all over the plastic bag inside the chamber at the end of the cycle. All I can imagine is that there was some oil in the vacuum line, and during the hard air return, the oil was being blown out into the chamber. It is possible that somehow the unit was tipped on its side during transport, but that seems somewhat unlikely. Another possibility, which seem smore likely, is that back-pressure on the oil forced some of the oil into the vacuum line, as the unit was transitioning from essentially sea level to my 7000 foot elevation.
Another problem that has yet to be resolved is how to calibrate the unit for my altitude. There is a calibration menu item included, but the instructions say to let the vacuum run until it reaches 000mbar, and then press Stop. In my case, however, it never goes below 192mbar, so I don't know whether it is properly calibrated not. I guess I'll have to try pulling vacuum on some water at various temperatures commonly in order to determine the absolute level of vacuum that is being achieved.
According to the PolyScience web site, unit is supposed to include a slanted shelf for use with liquids, but none was included in the package. I'm still trying to resolve this.
All in all, despite some initial familiarization problems, I think I'm going to be very happy with the unit.
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Not only does it work well, it's easier than hooking up the hose. You'll have to experiment with different vacuum levels to find the correct on for a particular container, since full vacuum will cause it to collapse.
I cancelled my order for the hose when I discovered this.
I wasn't talking about FoodSaver-style plastic containers, but about professional GreenVac stainless steel containers (a special kind of GastroNorm containers). Most of those wouldn't even fit into a Boxer 42.
My FoodSaver 2.3 L square container just barely fits in my MVS-31X, and so far hasn't shown any signs of collapsing. However, the tall canister is 20 mm high by 17 mm in diameter, and won't fit into any chamber vacuum I know of.
The GreenVac system looks like what I've been looking for. Does anyone know of a US distributor? The Salvis AG site out of Switzerland is very confusing -- I can't figure out what lids to order with what.
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I've ordered the MiniPack MVS-35XP from PolyScience, and it should arrive in a couple of days.
At least here in the US, they got a special deal from MiniPack to offer it as an exclusive, so you can only get it from PolyScience or a PolyScience dealer. I don't know about the EU or Australia, however.
I carefully considered the Henckleman units, particularly the new Lynks series, but by the time you added the H2O sensor, the vacuum sensor, and the printer, the price was over $4000, whereas the 35XP was closer to $3000 with shipping.
The 35XP uses a Bosch pump, unlike the MVS-31X, which uses an Italian-made DVP. It will be interesting to see what level of absolute vacuum I can achieve with the new unit.
The 35XP offers 100 different programs and includes a printer, which should help avoid the UFO (Unidentified Freezer Objects) problem, as well as dating the product. So each time I prepare something new, I can add that food type to the program, and thereby reduce the effort the next time around. Obviously this would be very handy in a restaurant, or even in a butcher shop -- Cids grocery store here in Taos uses a 45XP in that manner, to package liver slices and other speciality frozen items.
You can check the dimensions on line, but it is slightly larger than the MVS-31X. And wonder of wonders, they have moved away from their odd-ball proprietary thread on the vacuum port, to a standard 1/4" NPT thread, so it is easy to find a threaded barb that will fit in there. I used the same threaded barb on the MSV-31X -- it fit, but just barely -- and then coupled that hose to one that came with my FoodSaver. I put a some teflon tape around the little stud on the FoodSaver hose, and inserted it into the larger hose connected to the barb, and and plug the other end into a FoodSaver container, and it holds vacuum just fine. So you can just screw in the barb and run the unit with the lid open, then unscrew it afterwards. It would be a good idea to set up a program that cuts the seal time to 0, so that you don't risk melting the hose. The advantage is that you can put dry goods (crackers, etc.) in one of the FoodSaver containers, and pull a vacuum on it, without crushing the contents --unlike using a bag. You can also use it to quickly marinate something in one of the square FoodSaver marinade containers, although you can also do that in a bag, using the slanted tray to keep the liquid from running everywhere. Finally, since the FoodSaver containers have a one-way valve, you can use this set-up to hold something like a meringue under vacuum for an extended period of time, although I haven't tried that yet. I'm still looking for a vacuum lid for a Gastronorm hotel pan, as seen in MC, but I haven't found one yet. That might be handy for marinating large pieces of meat, or a whole lot of veggies.
Once the unit arrives and I get to play around with it a bit, I will probably order the gas fill adapter kit, since I already have a regulator and nitrogen tank, and I use the gas fill on my MVS-31X a lot, to preserve bread, etc.
I think the PolyScience MVS-35XP unit comes with the standard two 3mm seal bars, but I think I would rather have a 6mm plus a cut-off strip. Doug at Doug Care told me that I don't need to buy a new seal bar, but instead simply buy the appropriate heating strips and some Teflon tape, and rebuild it myself. I'll think about that, although the seal bars aren't THAT expensive, and it might be nice to be able to switch back and forth.
More feedback next week.
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Lead-weighted 35mm film clips would be ideal, but they are very hard to find in the digital era.
You might want to try sealing some marbles or ceramic pie weights or even lead wheel weights in a small bag, and then use a bag clip to hold the two bags together.
Just make sure that whatever you use doesn't interfere with circulation around the food bag.
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I know very little about the safety of potatoes cooked and then stored in an anerobic environment. I am a big chicken as far as food safety goes so I wouldn't store them for more than 24 hours before reheating and serving.
If you want to store them for longer once cooked chill in an ice bath and then keep well refrigerated (3C or lower) and use within 30 days. Cooking at 80C or above for more than an hour will kill of most of the bugs but not the spores of Clostridium botulinum that can lead to botulisum but if you keep it below 3C then they can't grow and produce toxin. Also even if there were some toxin present if then heating to 80C or above and holding for 10 minutes or more will destroy any toxin and so make it safe to eat. (Lower temps for longer can do the same but botulisum is not something to take risks with so make sure they are from a reputable source. Since we're talking SV I'd time it so core temp was at the given temp for the required duration.
Thanks for the input. All excellent advice but given a home fridge even though I can set it to be 3C, I cannot stop the door being opened and closed multiple times a day and thus affecting the temperature. I am happy to live in my super safe, obsessive-compulsive state and not take chances. There are much braver souls out there and their MMV. Again, thanks for the link.
Anna, even if the fridge door is opened and closed many times, that isn't going to significantly affect the temperature of any chilled food -- even if the air temperature goes up by 5 degrees C or so briefly, because the mass of the food greatly exceeds the mass of the air., and air is a very inefficient way to transfer heat. And although botulism isn't something to take chances with, the difference in growth rates between an average temperature of 3C and 5C would be miniscule. And if you want to hold the potatoes for longer than a week, you could always freeze them.
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a great way to make Creme Freche in your SV, seems very easy and certainly economical, I'll have to try this soon!
I posted this earlier, but it seems to have been lost.
Great post, but the link to SV Kitchen blog was even more interesting-- some of the most exciting SV recipes I have come across, despite owning many, many recent cookbooks.
After reading a number of the recipes, I went down to Whole Foods in Santa Fe with my most exotic shopping list ever, including monkfish (special ordered), jamon (had to get it at the Spanish Table), truffle salt (who knew such a thing existed!), canned poquillo peppers,Tuscan kale AKA "Dino" kale, fennel seed, pork loin, Calvados (got some for drinking, but also some Applejack for cooking the pork loin with apples recipe), dried porchini mushrooms, dried buttermilk, ahi tuna.
Thanks, Whole Foods!
Great find! I'll be visiting that site often!
Bob
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Eleven Madison Park was fantastic, but expensive. See my review on Travelocity.
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Yes, but only with distilled water at 14.5C.
And when I mention the issue to Doug Care, he said that he had never seen meat "boiling" either.
Maybe it depends on what side of the street you live? :
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I was talking to Doug at Doug Care (where I bought my MVS-31X) and learned something new.
First of all, occasionally running the machine on 99.9%+30 seconds (a couple of times a day, for example) will help to get rid of any water bubbles that might have gotten into the oil, perhaps because you were cooking Heston Blumenthal's triple-cooked french fries.
Second, if for some recipes you need to hold a vacuum for an extended amount of time, you can run the 99.9%+30 second program, and when it gets close to the 30 second mark, simply turn off the machine. It will probably hold a decent vacuum (and you will be unable to open the lid) for 20 minutes or so.
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GlowingGhoul, I've come to the same conclusion.
This morning, I went through the MVS chamber calibration procedure again. You put the machine into calibration mode, run it until the numbers stop incrementing, then do it again and hit reset wthen the number is one below the maximum reached on the previous run. But this is pretty obviously calibrating the vacuum setting against the maximum vacuum it is capable of producing, rather than an absolute setting.
So I went back to PedroG's chart at http://sousvide.wikia.com/wiki/Find_out_how_strong_a_vacuum_your_machine_produces, and tried to boil water.
First, I filled a coffee cup with crushed ice and distilled water, and measured the temperature as 0.01C. I saw tiny bubbles at that point, but certainly not a roiling boil.
Then it occurred to me that what I might be seeing was merely outgassing of the crushed ice, so I scooped out the ice and tried again. No boil.
To make a long story short, I had to go all the way up to 14.5C before I saw a reasonable amount of bubbles forming, so that was a true vacuum percentage of about 98.4%, as opposed to an indicated 99.9%.
Now, what could be the problem?
One possibility might be a leaking seal -- I see that the seal does not go all around the lid in on continuous piece, but is apparently cut and formed around it. I suppose I might be able to fill that tiny crack with some sort of soft glue.
Another possibility might be if I had water bubbles in the oil, perhaps from cooking Heston's triple-cooked French fries.
Or maybe there is a leak in the tubing or valve that lets the air back in at the end of the cycle.
I'm going ask blackp, who owns a Henkleman and who has also never seen meat boil, to check his absolute vacuum level with this procedure, as well as Douglas Baldwin, who has an MVS-31X.
In the meantime, I would ask anyone else on this list with a chamber vacuum to repeat these same tests. Maybe we can conclude something, finally.
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Although it doesn't appear that there's been any scientific study of the subject, you can easily demonstrate the drying effect of applying too high a vacuum to meat.
Thoroughly dry a piece of red meat, then seal it at 99% vacuum.
Watch the meat carefully as vacuum is applied, and, depending on temperature (but certainly by 96%), you'll see liquid boiling out of the meat.
Although the colder the meat is the lesser the effect, this will occur even if near frozen.
Open the package, and your once dry meat is now soaking wet with liquid on the surface. Leave it in the package for several hours, and the quantity of liquid removed from the meat will be much higher.
In the meat packaging industry, this is known as "drip loss" (though drip loss can be caused by other factors as well as vacuum). This is controlled by meat packers vacuuming to a lower percentage then heat shrinking the bags make them skin tight, rather than using very high vacuum. Freeze drying uses vacuum to intentionally accomplish the same effect, but to a much higher degree of course.
Most of the time, the H20 sensor stops vacuum at between 84% and 92%, before any boil off is visible.
Simply lowering the vacuum to 85% would probably avoid this problem in most cases, but because I do a lot of long cooks where the bag has a tendency to puff up (due to phase change) I like being able to maximize vacuum to keep the bag as tight as possible.
Other changes happen to meat in high vacuum as well. Large pores develop, changing the structure and texture of the meat (for the worse or better I'm not certain yet). There are food industry studies on line documenting this pore development effect.
For storage I want to keep the meat and it's liquids intact as far as possible, but...
I am experimenting with beef brisket at the moment, intentionally removing moisture post smoking at 99% vacuum (controlled by varying the "hold time" after 99% is reached), then opening the bag, pouring out the liquid, drying the meat, and rebagging for sous vide. Thus far I've found the beef flavor intensified, texture improved (in the traditional BBQ brisket falling apart sense), but required cooking time increased by 10% or so (lower heat conductivity within the meat perhaps?).
Buy a chamber vacuum, become a mad kitchen scientist
There is something very strange going on here. I routinely use a 99% vacuum on rib eye steaks, etc., and I have NEVER seen the boiling effect that you (and Dave Arnold) have reported. I don't think Nathan has seen it, either. I am vacuuming beef that has generally been in the fridge, so it's down around 5C or so, maybe less, as opposed to being at room temperature.
I have calibrated my unit in accordance with the instructions, to take into account that I live at 7000 ft. But it occurs to me that perhaps BECAUSE of that fact, the meat has already been subjected to a partial vacuum, at least compared to sea level. Could that cause the difference?
Hmmh. Yesterday I packed up eight Angus rib-eye steaks, all freshly cut at the same time from the same grocery store. Seven were packaged at 99%, as I usually do, but one I set for 99% plus 30 seconds. I didn't see any visible boiling, but today when I took the package out of the freezer, I noticed some ice crystals inside the package, and the bag didn't seem tightly sealed. The others didn't show that. So perhaps there was some extra liquid extracted, if not immediately than some time later?? I didn't see any kind of a leak in the seal.
The only other explanation I can think of is that you are using a Henkleman machine and I am using the MVS-31X, and perhaps the calibration procedure is somehow different -- maybe mine isn't pulling a true 99%. Then again, blackp has a Henkleman as well, and I don't think he has seen this effect, either. Maybe we both need to boil some ice water to check the calibration better.
Or maybe there are differences in the type of beef?
Sous Vide: Recipes, Techniques & Equipment, 2012
in Cooking
Posted
I've never had a problem with any kind of toughness or stringiness with brisket cooked at 55C for 72 hours.
There are differences (minor) in connective tissue -- see Harold McGee. But sufficient time will break down almost anything (except bone) at pasteurization temperatures.