nathanm
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The comments about food safety above are good, but here is my addition.
The rules of thumb about the "danger zone" are based on a mixture of good science, with a lot of well meaning safety factors and conservatism applied to make sure people don't get sick. The USDA , FDA and other health agencies are very anxious to avoid sick people, and they are aware that people have inaccurate thermometers, so they tend to oversimplify things. For example, any guide that just talks about temperature is only telling you half the story - you need to hold that temperture for a period of time to achieve food safety.
The so called food "danger zone" is not a hard and fast thing. Bacteria grow at any temperature above freezing, and they generally stop or slow down above 125F. Many experts would say that the danger zone is 30F/-2C to 130F/54C. FDA / USDA generally says 41F/5C to 140F/60C.
However, it should be noted that many very common foods are not cooked to the USDA / FDA guidelines at all. Rare beef that is "bleu" can be as low as 104F /40C, rare is usually 120F / 49C , Medium rare is 125F/52C to 130F / 54C, and so forth. Fish is cooked even less. Many chefs serve salmon mi cuit at 100F/38C to 104F/40C, while most fish is better at 113F / 45C.
If that is in the danger zone, how can that happen? How is it possible to serve food cooked at these temperature less than 140F/60C ?
There are several reasons. One is that some food is less contaminated that others. The interior of a muscle food, like beef, or even fish, is only very rarely contaminated. Ground beef is a far more serious health concern than a steak or roast as a result.
Also, because of the surface effect, the surface of a steak is much more vulnerable to contamination, but it typically is heated to a higher temperture than the interior, and held their longer (so the interior will be done). So, the FDA Food Code only requires that the exterior of a steak be brought to 145F/63C, and they don't care about the interior temperture at all (so long as the whole thing isn't held too long).
Chicken, on the other hand, is much more likely to be externally contaminated, and is more likely to have salmonella. Heston Blumenthal recommends 147F / 64C for chicken for this reason. However, the USDA (and many cookbooks following them) recommend 160F, at which point the bird is virually guaranteed to be dried out.
As the Blumenthal quote in the previous posting says, 12 minutes at 140F/60C is one standard, but there are actually a wide range of times and temperatures. Techical publications often discuss this in term of how many "log-cycles" or "D" - which means a factor of ten reduction in the bacteria. 140F/60C for 12 minutes is a 7D, or 10,000,000 factor reduction. In practice most food safety experts believe that 5D - or 100,000 fold reduction is enough, others want more.
The longer you are going to hold or store the food prior to eating, the more D you need, because during the holding time any remaining bacteria can grow back. Canned food is typically processed to 12D.
You can achieve the same results by longer time at lower temperatures, or less time at higher temperatures. Here is a table
130F 54C 112 mintues
135F 57C 35 minutes
140F 60C 12 minutes
145F 62C 4 minutes
150F 65C 1.5 minutes
165F 74C 2 seconds
Note that these are consitent with the US FDA Food Code regulations.
This shows how silly it is to give requirements in terms of temperature alone, without taking time into account. 140F is NOT SAFE if done for a very short time. It is safe done for 12 minutes. It is pointless beyond 12 minutes (unless you need more than 7D reduction).
So, if you want to cook rare beef sous vide, you need to cook until the core sits at that temperature for that long. If you use 130F/54C bath temperature, a thick fillet might well take an hour just to come up to that temperature, so that means putting it in a water bath for a total 2 1/2 - 3 hours. Then sear the outside in a pan - it is delicious this way, and the other benefit of sitting at that temperature for this long is that it will be extra tender due to collagen break down.
Meanwhile cooking below 130F for a long time period is not recommended. The highest temperature common pathogen can multiply up to 127F. However, you can still eat food cooked less than that if you don't wait too long. The flip side of cooking times/temperatures are the recommendations for holding times - i.e. if you are in the "danger zone" how long can you let it stay. The FDA recommends that in the danger zone between 41F/5C and 140F/60C, that food not spend more than 4 hours. Many souces, in an abundance of caution cut that in half to two hours, but 4 is the regulation.
A more precise chart of time and temperature is given here
This guideline explains why we can eat rare beef without getting sick - at 120F/49C the safe holding time (using similar criteria to FDA rules) is 5.6 hours. A steak which is taken from the refridgerator, prepped under clean conditions, then cooked, served and eaten in 30 minutes is well within that time period. Salmon mi cuit at 113F shouldn't sit more than 4.6 hours. Personally, I would not go anywhere close to those limits, but the interesting thing is that you don't have to for any food cooked to order in a home or restaurant.
Here is a good general guide to food safety- written for home chefs, but with a lot of interesting technical information.
Note that all of the above are for general conditions - if the acidity (pH), salinity or even sugar level is above certain values, then you don't need heat at all. That is why salt cod can stay at room temperature, and why maple syrup, or corn syrup also keeps a long time.
People cooking in restaurants have the additional requirement that health department inspectors and regulations may impose, which can often have very little to do with the reality and science of microbes. That is a different topic altogether.
Another point that I should make is that the above discussion is about times and temperatures for food that is to be served immediately. Storing food after it is cooked has another whole set of issues. When you store food for a long time after cooking, you give any remaining bacteria a chance to come back and grow. So you need to be much more careful.
When people talk about sous vide, sometimes they mean cooking for immediate service (that's what I generally do). Sometimes they mean cooking, chilling then reheating up to a week later. Storing the food after cooking, and also how you chill it and how fast you chill it require a higher degree of food saftey - it's another topic altogether.
OK, so that is my view.
For an officia, but hard to read, viewpoint you can plow through the US government version, the FDA regulations are called the "Food Code", and you can find it here. The full set of tables on times and tempertaures are found here.
They have a section on "reduced oxygen packaging" - i.e. sous vide, but it is mostly regulation speak without much information. Also, it is mainly about food sold at retail in vacuum packages.
I hope that helps.
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Jackal10 is correct - they excel for low temperatures. Mostly I use water baths between 45C / 113F (for fish), and 82C / 180F for confit.
They are great for cooking for a long time - up to 24 to 36 hours.
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Rational ovens are great - I have two of them. I love them and if I had to choose between them and water baths, I would keep them. But I don't have to choose, so I have both!
There is inevitably a bit of variation in the temperature of any oven. I have calibrated mine and as the heating element turns off and on to maintain temperature there are variations of plus or minus 2 degrees at least, and on some ovens as much as 5 degrees. Gas versions are worse than electric.
This is a cyclic variation - it cycles around the set point. The average temperature is correct, but over a few minute time scale it varies.
At the high end of the oven range this is not bad, because if your are at 400F, then there really is not much difference between 395 and 405.
However, if you are cooking salmon mi cuit and want it retain the raw look, then you must cook at 104F. In that case plus or minus a couple of degrees is a much bigger problem. Or for cooking red meat sous vide (beef tenderloin, rack of lamb), you want to know the temp pretty accurately so that know whether you are doing rare, medium rare. I generally do rare at 125F, medium rare at 130F. With a water bath I really know what the temperature is.
Also, note that the Rational does maintain the right temperature ON AVERAGE. For a large piece of meat that variation does not matter, because a big piece of meat (or other food) takes a long time to cook and small variations do not matter much. So, when I cook a big beef rib roast in the Rational, I use a cooking program that will hold it at 125F or 130F, with an internal tempertaure probe and it will do a great job.
But Rational themselves do not recommend using the internal probe with meat less than about 2 pounds (1 kilo) weight. The temperture cycling is one reason.
Lab water baths generally maintain tempertaure to withing 0.25 degree, many to within 0.1 degree, and some of them down to 0.01 degrees. When you plop the food into the water bath the temperature drops a bit - they can't help that, but as it returns to the proper temperature it will absolutely not overshoot by more than the amounts above.
Now, do you really need 0.1 degree accuracy? No, even for critical things like salmon mi cuit, you don't need that much. However it sure doesn't hurt.
Note that most digital thermometers used in the kitchen are only accurate to plus or minus 1 degree F, and many of them plus or minus 2 degrees F.
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Technology in the kitchen seems to evolve fairly slowly - most of the equipment we use hasn't changed in generations. One new area that has been quite exciting is the use of laboratory equipment in the kitchen. Chemical and biological laboratories follow "recipes" with even more precision that chefs do, and as a result they have some equipment that is very worthwhile in the kitchen.
One example is laboratory water baths - a very precise sort of bain marie. These have become widely used by cutting edge chefs such as Ferran Adria of El Bulli, Heston Blumenthal of The Fat Duck, and Wylie Dufresne of WD 50.
The water bath is just what it says - a thermostatically controlled bath of water in which you can immerse things to cook them. Typically they hold the temperature very accurately - to a small fraction of a degree. To cook with a water bath you must immerse the food in the bath - typically this is done by sealing the food in a vacuum packed bag (sous vide), although you can also place a pot or bowl in the water, much like a bain marie or double boiler.
This post is intended to be a chef's guide to the various sorts of water baths, and where to buy them.
There are several types of laboratory water bath that are relevant. Here is a manufacturer's web page that shows several varieties. Here is a different style
The first style is typically called an "immersion circulator" - it is a precise heating element, thermostat and pump. It is meant to be suspended in a tank or pot - generally by clamping to the side. The pump keeps the water circulating, much as the fan in a convection oven.
The good news about immersion circulators is that they are very versatile - you can use them with any deep container that holds water - a large stock pot or tank. Most kitchens have deep hotel pans or other containers that could be used.
The bad news about immersion circulators is that when you stick the unit onto the pot or tank, it is very difficult to cover the tank and ensure a good seal. This means that the water will be subject to a lot of evaporation. For some uses - keeping food warm, or quickly poaching fish, this is fine. For other uses - like doing confit in sous vide where the cooking time is 7 to 10 hours, it is a real problem. When the water level drops to a certain point the unit will turn off, leaving your food to come to room temperature, and probably to spoil. I ruined a batch of short ribs this way once.
One way to combat the evaporation is to use floating balls on the top of the water - such as a bunch of ping-pong balls. Lab supply places like CP, Fisher, VWR sell special ones, but ping pong balls work. However, it is much easier to use a water bath with a tank cover.
The second type of water bath is better for general purpose use – it is basically an immersion circulator that comes with a built in tank and cover. These are called "water baths", "circulating water baths", or something similar.
One variety only heats the water. Another variety is able to do both heat and cooling so you can keep the water at a temperature lower than the kitchen temperature. Those units are much heavier and more expensive, and for the moment there is much less call for chilled water bath than a hot water bath in the kitchen. So, I’ll restrict my comments to the heated ones.
Circulating water baths of this sort typically have inlet and outlet port which allow them to pump water through tubing to other scientific equipment. For kitchen use you will want to use a loop of tubing to connect the input to the output.
If you want a water bath for cooking, you probably want a circulating water bath – it is like a convention oven in that the pump causes the water to circulate and thus prevents cold spots. There are some less expensive units, usually called utility water baths that don’t circulate – I do not use them much myself. The only advantage they have is if you wanted to cook right in the unit, because they are easy to clean.
Some people report using home appliance slow cookers, or crock pots, as water baths. They are cheap, but they have several problems. First, they don't have accurate temperature control - usually it is "high" and "low" and neither one is calibrated properly. Second, they don't circulate the water. I do not recommend them.
There are other kinds of laboratory water baths – for example orbital or shaking water baths. These have a cage assembly inside the water tank, which shakes or vibrates via a motor in order to gently agitate containers placed in the cage. This is very important for some kinds of biological work, but it is not required for cooking, and is usually much more expensive.
All water baths and circulators come in either analog or digital form. The digital versions are generally easier to set and read, but either one will work.
There are dozens of manufacturers of water baths. To add to the confusion, there are also lots of companies that sell other people’s water baths under their own name.
The three largest scientific equipment companies are Fisher Scientific, http://www.vwr.com/index.htm ]VWR International and Cole Palmer. Each of them sell several brands of water baths, including one or more product lines under their own brand name. Note that they do not actually manufacture the baths, but it certainly can look that way because of the private label branding.
These supply houses sell to scientific labs – such as pharmaceutical companies or government research labs. As a result they are NOT cheap – this is a market where the customers are not very price sensitive. The units are generally $800 to $1500 depending on the size for a circulating water bath or immersion circulator. High end units can be $4000 or more. These are almost always well made and sturdy, but it comes at a price, especially if you buy them new.
The other way to buy is second hand. Because these units are built to high standards for scientific purposes, they generally last a long time. The two main sources there - used from dealers in used lab equipment, or on eBay.
Water baths are so commonly used in labs that there are literally hundreds of them for sale from used equipment dealers. Here is one example site. Models that are suitable for chefs generally go for $250 to $350. eBay generally has plenty of them also, several dozen at any point in time. The price on eBay is highly variable. Some of the sellers hold out for a lot, others don’t. I recently bought one very nice 20 liter water bath for $150. Two days later a second unit of the identical model went for $220.
To find them on eBay, the best method is to go to “see all eBay categories”, then “Business and Industrial”, then “Healthcare, Lab & Life Science”, then search for water*, bath, or circ* .
Using a water bath is pretty simple – set the thermostat at the right temperature and turn it on. That is the basic set up, but there are some other details. Most digital models allow you to switch between Fahrenheit and Celsius temperature scales. In addition, there is usually an over-temperature cut off which turns the unit off if some for reason it gets past a certain temperature. On some models things like how to switch between F and C is not obvious – then you need a user’s manual. Many of the better manufacturers, like Lauda have PDF versions of their manuals on line, even for discontinued models.
If your water is very mineralized, you may get deposits on the heating element. These can be cleaned as for any sort of heating element in water. Or, you can use softened water.
The size water bath you need depends on what you are going to cook. In general, a 10 liter model is the smallest you want to use – although I have a couple 7 liter ones that I use for small batch experiments. 20 liters is better. Sometimes you can find even larger ones, but the problem then becomes the fact that the wattage may not be enough to handle that much water.
Most of these units are relatively low wattage – 1000 watts to 2000 watts. This means that it takes a while for them to come up to temperature – often 20 to 30 minutes. The larger the water tank size, the longer it will take to heat up. However, by the same token the larger the tank, the less the temperature will drop when the food goes in.
If you get a used unit you will need to clean it very thoroughly before using it. You may need to use a water scale remover on the heating element. Replace any tubing with new rubber or plastic tubing rated to take the temperature you will use.
I generally leave the water in the water bath between uses - the tanks are stainless steel, and everything seems to be fine with that. Periodically it should be emptied - and always emptied if food particles spill into the water.
Note that in all cases you are cooking with the water as a means to heat the food, but the food is not directly in the water - it is sealed in a plastic vacuum bag, or it is inside a container . In principle, you could poach directly in the water, but in that case case you would need to clean the unit very carefully afterward, because food particles could get stuck in the pump. "Utility" water baths, mentioned above, that do not have a circulation pump are easy to clean, so they could be used that way.
Most water baths are designed to go from room temperature up to 100C / 212F. A few of them have the ability to go higher if you use oil in them, however, they are not designed for use as a deep fryer – they are intended for various synthetic oils.
That should serve as a basic primer to water baths themselves. Their use in cooking depends on what you are after, of course. The sous vide thread (elsewhere on eGullet) discusses that form of cooking. Water baths with sous vide are a great way to cook.
Convention steam ovens, such as Rational, can also be used instead of a water bath for sous vide or other cooking. However, water baths have the advantage that they are generally much smaller, and cheaper. I use Rational ovens when I am doing something big, but for a small quantity, or when I want to cook something for long periods of time (like up to 36 hours for some things), it is difficult to tie up the Rational. A water bath is much more practical in that context. The temperature control is also more accurate.
You can also use water baths to keep things warm. Any deep stainless steel container can be immersed with the bottom in a water bath – much like in a steam table, but with more accurate temperature control. This lets you keep things warm without sealing in a vacuum bag. As another example, when I make a warm foam, such as warm potato foam, with the ISI foamer, I fill the units then leave them in the water bath at 140F / 60C.
This may be more than you ever wanted to know about water baths, but hopefully somebody will find it interesting.
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I am not surprised by the orange fat. When you cook things in a sous vide bag, the various aromatics you put in the bag become extremely concentrated. There is literally nowhere for the volatile flavor and smell compounds to go. In conventional braising they evaporate into the room that is what makes the smell you get in the oven, room etc.
So, one of the rules in sous vide is that you have to be very careful about aromatics and seasonings.
If you tried the same thing with orange zest in a sous vide bag with a neutral oil, for that many hours, you would get an orange oil extract. Indeed poaching oil at low temperature with zest is used in many recipes to make a citrus oil. So, thisi s what I think happened to your fat.
It is possible that this also contributes to the waxy smell you report. Goose fat should not be a problem at all - in fact confit d'oie - confit of goose leg - is a traditional preparation in France. Personally I like it as much or better than duck confit.
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There is a duck confit thread on egullet where we have been discussing sous vide duck confit recently - look there for details. But the short answer is 82C / 180F for 10-12 hours.
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I just finished my first round of duck confit experiments sous vide.
180F for 11 hours was plenty in my test - good texture, and frankly it could have stopped sooner, at least for how I like the texture.
I tried Paula's salting ratio, 22 grams / lb of duck legs, which was fine.
I am quite skeptical about marinating with spices and aromatics (thyme, cloves, garlic etc.). Cooking with them in the sous vide bag certainly does have a result. Citrus would also have a very strong result. But very little flavor penetrates from just putting such things onto dry meat.
I also tried brining the legs - this is not traditional, but there is no reason not to do it. The action of the salt on the duck meat is the same either way. The brine that I used was a simple poultry brine - 4.5 grams salt per liter of water (16.5 grams per gallon) of diamond crystal salt, and the same amount of sugar. I let it sit for 12 hours in the brine - the same as the dry salted legs.
In retrospect, this was too long, or the brine too strong, because it is a bit too salty - not terrible but a bit too much. I will evaluate another sample in a few days. I was curious about the sugar since it is totally non-traditional, but many brines for poultry and pork have 50% to 100% (by weight) sugar to salt ratio. There was an effect on flavor, but not as strong as I would expect.
The main difference between brining and dry salting is that you would expect deeper penetration of the meat, shorter time (as I found out) and more even results.
I also did various experiments putting different aromatics in the bags. Another experiment was pure duck fat, versus other fats (duck fat with some canola oil, pure canola oil, butter). The traditional preparation may be best, but what the hell I thought I would try some variations.
but I have not opened them all, so the results will be posted later.
One post asks whether you can leave the legs in the fat and jelly in the bags. I have. There is no reason the jelly will hurt it (as long as refridegrated).
To remove from the vaccum bags, I slit the top and then pull the leg out while squeezing hard with my hand on the bag to leave the jelly and fat behind in the bag. I then take this from several bags, gently reheat to melt the fat and jelly and let it cool at which point the fat and jelly can be separated - you can do the upside down jar trick that culniary bear suggested (if you trust your jar!).
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Great - I will experiment. Come on by where??
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I have 8 muscovy duck legs marinating right now, will cook them sous vide tomorrow.
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My sample isn't here yet - probably next week.
How strongly does it hold? It can't be as strong as a single piece of meat, but can you turn the composite beef tenderloin on the grill without it falling apart? When cut with a knife does it split along the "glue" joints?
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You may want to check out the duck confit thread...
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I just ordered "cooking is fun", and also the "hip chefs hot cuisine" book. Thanks for the suggestions!
Also, thanks for the suggestion of freezing a gelee....I will try that but from previous experience I think that the right combination of gel + fat + dry matter must be achieved. Also, there is a question of which sort of gel to use - ice cream stabilizer in higher than normal concentration, or something else like sheet gelatine, micri, agar...
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Yes, I have that book.... it is very good but it does not help much on this topic.
For example it has Langostine ice cream - which is the sort of thing that I want to make.
However, the recipe they have is full of sugar:
600 grams milk
60 grams butter
40 grams egg yolk
60 grams sugar
90 grams atomized glucose
80 grams non-fat dry milk
4 grams stabilizer
130 grams Langoustine reduction (like a bisque)
Or, Pistou ice cream (pistou is French pesto - basil, garlic, pine nuts...)
600 grams milk
60 grams olive oil
40 grams egg yolk
60 grams sugar
90 grams atomized glucose
100 grams non-fat dry milk
6 grams stabilizer
6 grams salt
1 gram black pepper
40 grams pistou
Compare this to one of their recipies for vanilla ice cream
600 grams milk
60 grams butter
80 grams egg yolk
128 grams sugar
34 grams atomized glucose
50 grams non-fat dry milk
2 grams stabilizer
1.5 vanilla beans
So, the difference is that the "savory" recipes have 140 grams of sugar + glucose while the vanilla ice cream has 162 grams of sugar + glucose. Not much of a difference. Changing the ratio of sugar (i.e. sucrose) to glucose will effect sweetness, but it is clear that all of these are really quite sweet.
There is also more egg, and less powdered milk in the vanilla, but that is a different sort of change.
I have not made these recipes (but have made other things from the book). It is great ice cream, but is not the truly savory version I am looking for. Their "savory" recipes are still very sweet ice creams.
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When you know what works and what doesn't, let us know!
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All great advice - thanks. I have and use invert sugar, and the various points about the paco jet are well taken.
I have been hoping that there is a product out there that somebody has used that would be better than invert sugar.
One example would be a sugar that has NO sweet taste. Such things exist. Long chain glucose polymers have this property - once a molecule gets past a certain size, it is difficult for it to bind with taste receptors. This is why invert sugar and corn syrup are not very sweet. However, they have a certain fraction of smaller molecules which makes them somewhat sweet.
Fats are clearly a help. The suggestion to look at sugar free ice cream recipes is a good idea - they are still trying to be sweet, but they have to cope with reduced sugar.
Glycerin is a good suggestion, along the lines of what I am looking for - I will try it.
This suggests to me that lethicin would also be good. I have used it to make foams, but it may have a use here.
Gelling agents are another possibility. If you make mango sorbet in the paco jet, the pectin in the mango whips into a mousse like texture - it practically will not melt! Chocolate mousse in the paco is similar - you use gelatin, but this is pretty tricky because small changes will make it no longer a mousse, so I only rarely do this.
I have the 98/02 book, and Balaguer's book and probably every other high tech / high end cookbook. At the moment there is essentially no coverage of paco jet, as you point out. Mostly that is OK because a little trial and error works.
I do make sorbets in pacojet - they can come out perfectly if everything is balanced correctly. A little stabilizer (sevarome) does help if you hold it, particularly for some ingredients - mango certainly does not need it.
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Actually, the paco jet requires less stabilizer and less sugar than conventional ice cream / sorbet freezers. In fact, one generally makes ice cream and sorbet with no stabilizer at all in the paco jet.
The issue here is finding the right substitutes for sugar. Sugar is a major factor in the texture of ice cream and sorbet, and if you want to make a savory version you need to use something else.
The issues are actually a lot worse for a conventional machine than for paco jet, but that really does not matter compared to the big question of what to use?
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I am interested in making savory (non-dessert) ice creams and sorbets. A number of chefs have done this here and there, but there does not seem to be any systematic approach (that I am aware of anyway) as there is for sweet ice creams and sorbets.
In making a dessert ice cream or sorbet, we have rules of thumb and recipes for how much simple syrup, how much butterfat, how many egg yolks can be used for various ingredients. If you want to be careful you can even measure the sugar level in the fruit with a refractometer to fine tune to this to the ripeness of the fruit. There is some variation in the final results, which suites different chefs. But there is a body of knowledege that says hey, too much sugar and it won't freeze at all. Too little and it is hard as a rock. In the middle is where successful recipes lie.
In particular, when we make an ice cream or sorbet we rely on a number of ingredients to control the texture and body. THis includes various forms of sugar (sucrose, dextrose, invert sugar, corn syrup...) - which lower freezing point and contribute to texture. It also includes fats (butterfat and egg yolk) - at least in ice cream, but not in sorbet. It also includes things like powdered milk, and stabilizer (which is usually a form of gelatine or starch).
The most important problem for a savory ice cream is that you can't use the sugar, or anyway not very much. Some "savory" ice creams and sorbets are nearly as sweet as their dessert counterparts, and achieve the savory label by balancing the sugar with acidity. However, that is NOT what I want to do. I want to make some ice creams and sorbets that are not sweet at all, but still have the creamy texture of their dessert counterparts.
I use a paco-jet and this problem comes in the following form - you can fill the PJ beaker with anything - savory or not. But unless the feezing point is decreased a bit, and there is the right additives, you get a powdered snow, not an ice cream or sorbet. Ferran Adria at El Bulli has taken to serving these frozen powders, which is another fine dish, but it is not ice cream or sorbet.
So, if we can't add sugar, what can we add to get texture of the sort that we expect from a dessert ice cream or sorbet?
I have been using, or have considered:
Cream
Butterfat
Egg yolks & cream (i.e. like creme anglais without sugar)
Egg whites
Stabilizer (commercial ice cream or sorbet stabilizer)
Gelling substances (agar, Micri, pectin, gelatin)
There are other things that could in priniciple work. Salt could, for example, depress freezing point, but by the time there is enough salt to do that, you don't want to eat it. We tolerate a lot of surgar a lot better than we tolerate salt.
A long chain sugar molecule of some sort might have the texture properties of sugar, without being tasted as sugar. Corn syrup is very close to this, but it still is fairly sweet.
Anyway, of the things I have tried, some of them work, and some don't. I don't have enough successes at this point to claim that I have any general methods that work.
I am curious as to whether other people have tried these things, and if there is either any trick I am missing, or anything new I can try...
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So, what was the final timing? It was 10.5 hours, then a "couple" hours more. So, does that mean 12 hours or 14 or ??
This is consistent with what I would guess. Increasing the temperature a little bit might help get the texture better. It may also shorten the time, although this dish is never going to be fast food!
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I was told by the Ajinomoto sales rep that shelf life is 6 months if you vacuum pack and keep in freezer.
It is $75 per kilo for one form, and $50 per kilo for another form. However, since you use much less than 1% Activa to the meat or shrimp or whatever, then this works out to be pretty cheap. 100 kilos of meat costs a lot more than $75 ....
Anyway, I have some coming, and will experiment with it. Hopefully others will too...
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You don't need to thank me - its my pleasure to contribute...
As you say, the ability to cook precisely in temperature without being precise about timing and without fear of overcooking is one of the attractions of sous vide. It is great alternative for things that otherwise have to be cooked to the second.
Most high heat things I now cook slowly via sous vide, then quickly sear the surface at even higher heat than I would normally use. Fois gras, for example, is excellent this way - particularly if you want to cook a whole fois gras. You can make the inside perfect, then sear the outside... Cooking only by searing in a pan requires much more precise timing. Fish, shrimp and lobster are all great this way - you can avoid overcooking without worrying about timing.
The other class of items that are good done sous vide are preparations like confit, or braised dishes, that even in conventional cooking have long slow cook times.
With confit in particular, it lets you use a much smaller amount of fat and makes clean up easy.
As soon as I can pick up some ducks I'll give it a shot and verify the times and temperatures...
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Most of my experience with making confit of pork (shoulder, butt, belly) and lamb (shanks). In general I cook these at between 170F (77C) and 180F (82C) for between 8 - 12 hours. The results are very much like duck confit.
This temperature, along with ample fat (rendered lard, duck fat, olive oil) gives you a texture that is very similar to duck confit. I have been served sous vide duck confit in restaurants and I believe that the numbers would be similar.
At lower temperatures, or for shorter times, it does not turn out like confit at all. So, I think that this was part of your problem.
Recall that the original recipe posted in this thread by Culinary Bear was 90C for 12 to 14 hours. Sous vide does not speed up the cooking, so I would expect the times to be similar.
As a base line for duck confit I would suggest 180F (82C) and letting it go for at least 8 hours. Package the legs invidually, 1 to a vacuum bag - that way you can sample them at invtervals. You might want to try more like 2 -3 tablespoons fat per leg.
Take one out at 8 hours, and then periodically up to 12 hours. If that does not work, then try longer time periods - up to 14 or even a bit more. It is possible that you would need to go higher temp - to 200F (90C) - but I doubt that. My experiments with pork suggest that you are better off at 80C to 82C.
In general, sous vide lets you cook at a lower temperature for longer - for example many people braise short for as long as 36 hours sous vide, but at lower temperatures than normal braising (60C to 66 C - 140F to 150F).
The marination should proceed conventionally. There is no reason to suppose that sous vide cooking would change the marination process for confit. That may be part of the issue with your approach. So, if I am brining pork, I do it conventionally, then cook it sous vide. The same should be true for duck confit - follow the conventional recipe up to the point of cooking, then seal the legs in the bags with fat..
There are vacuum systems for doing marination, using vacuum marinators and tumblers - I have one of those too, but it is VERY different than sous vide.
It does not matter all that much whether you increase the temperature gradually or not. In fact, I would recommend not. As it stands, sous vide is pretty gentle cooking. Just use a water bath at 180F (82C) for the whole time.
What you are trying to do with confit is raise the temperature of the meat to the desired level, then let it sit there for an extented period of time while some parts of the meat break down - collagen to gelatin, fat rendering etc. The quicker the interior reaches the critical temperature, the more time that it will spend doing the conversion process.
In normal cooking you are using a flame or other heat source that is WAY hotter than you want the meat to be, so you have to be careful and time it carefully. Here you are using a medium (water in a water bath, or steam in a steam oven) that is the same temperature as you want the meat to be.
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A photo would be great...
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Thanks for the information on piping etc - it will be interesting to try and make shrimp "pasta".
I have had faux-pastas of paramesan cheese done by Ferran Adria, and also by Marc Veyrat. Veyrat's version was much better - it was a bit more delicate, and instantly melted in your mouth. Adria's version was a bit stiffer - more al dente, and slighly rubbery. I assume that the difference is the gelling agent they used.
I wonder what texture the shrimp pasta tastes like.
I've eaten at WD50, but alas the shrimp pasta wasn't on the menu at the time - will have to go back! Everything else I had there was wildly inventive.
I don't see why you couldn't make rare beef "pasta" - at that point it won't look much like pasta anymore but why not....
Can't wait to get my samples of Activa....
Anything else cool like that lurking out there?
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Replying to several posts...
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The water temperature in the water bath is the external temperature - the heat soaks into the food and ultimately it all comes into equilibrium at the same temperature. However, that takes a while, depending on the thickness, and on the temperature conductivity of the food. A piece of styrofoam would take longer for the center to come into equilibrium than a block of copper, because copper is an excellent conductor of heat, and styrofoam is a very poor conductor (i.e. a good insulator). Meat is somewhere in between in conductivity.
You can do the same thing in an oven - I use a water bath because most ovens are not accurate at low temperatures.
A slow cooker filled with water would be another sort of water bath. Slow cookers are not that accurate either, and generally don't have much temperature control. The manufacturers are scared about somebody getting sick from slow-cooked food at too low a temperature and suing them, so they generally make the lowest tempertaure like 200F. This would work for confit, but you generally get better texture at a somewhat lower temperature. The higher you go the more the risk is of overdoing it, and being left with mush. The time would be less than at 180F.
Some cooking is aimed at bringing the food to an internal temperature and then you stop as soon as it does - say, in cooking a steak. Confit, and most forms of braising, are about bringing it to a temperature, then letting it sit there for a period of time to allow a chemical conversion to take place - like collagen denaturing into gelatin, fat melting etc. Those changes are what makes confit what it is in terms of texture and taste. The rate of the changes depends a bit on temperature - you can speed it up or slow it down a bit. However the unique aspcets of confit depend on long slow cooking.
So, the long time cooking time is partly because it takes a while for the heat to soak in - but that is probably not more than an hour or two of the cooking time. The rest is letting the meat sit at temperature to change.
In my experiment last night I did boneless pork butt confit, and lamb shank confit. I tried it at both 9 hours and 12 hours at 180F. The 9 hour version was fine, the 12 hour was a bit more tender. Either one would be acceptible. Depending on the meat, and the thickness, you might be able to cut it down lower than 9 hours, or even less if move the temperature up a bit. However, ultimately you risk moving into somethnig that is not confit like.
Duck legs are significantly thinner than a lamb shank (say have to a third less) that should cut an hour or so off the time right there.
Note that none of these parameters are super critical - the difference between one extra or one less hour is only a 10% effect. As long as your temperature does not way out of whack it is hard to over or under cook this unless you are off by many hours.
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Flavor would presumably develop during aging the same way in a vacuum bag as the traditional way. Part of the point of preserving meat this way is that the layer of fat sealed out oxygen - that is also what the vacuum bag accomplishes.
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I store the food as I cook it - i.e. if it is on the bone when I cook it, I leave it on the bone for storage.
Sous Vide: Recipes, Techniques & Equipment (Part 1)
in Cooking
Posted
FYI - I just started a thread on laboratory water baths for sous vide. Also quite a bit of information on food safety.