KitchenSavvy

Getting to the Thick of Things

I have heard it said that when making pasta you should add a bit of the water from the cooked pasta to the sauce to thicken it.  Does this really work?

--Hayden

Presumably, the idea here is that starch leeches out of the pasta into the surrounding water and that this starch is what will thicken the sauce.  I think the first question I need to ask is this, "If the starch was going to make something thicker, why didn't it thicken the pasta cooking water, itself?"

"Ah, but ...," you say, "... it's the interaction with the sauce that make it thicken it."  Not likely.  For tomato sauce in particular, its main components, other than spices, fibre and water, are the acidity and sugars from the tomatoes.  Both acid and sugar inhibit the thickening action of starch, so the resulting solution would be less thick than the combination of the pasta water and the sauce , not more thick.  Cream based or other sauces would be more neutral to the starch and we are back to the original question, "Why didn't it thicken the cooking water?"

Robert Wolke, author of What Einstein Told His Cook: Kitchen Science Explained and What Einstein Told His Cook 2: The Sequel: Further Adventures in Kitchen Science, describes an analysis he did of just how much starch is dissolved in the water after cooking pasta.

"I cooked eight ounces of spaghetti in three quarts of water for the six minutes recommended on the package, fished out the spaghetti and boiled the cooking water down all the way to dryness to see how much starch was left. (The final stages of evaporation were done in a dish in a 220-degree oven.) Then I weighed the dried starch.

I found nine grams of starch in the entire three quarts of cooking water. A little calculation showed that, if you were to add a quarter-cup of this water to a pint of sauce in an attempt to thicken it, you would be adding about one-fifteenth of a teaspoon of starch.¹"

To put that in a little context, if you were making gravy, you would use around somewhere around a tablespoon and a half of wheat flour to thicken a cup of liquid.  That amount of flour would contain around 9 grams of starch, depending on type, the same amount as in the entire three quarts of water. 

Marinara sauce is around 80% water (USDA Nutrient Database), so a 3 cup recipe would have around 2.4 cups of water in it.  One-fifteenth of a teaspoon of starch would be enough to thicken around 1 teaspoon of water to the consistency of gravy.  That's about 1% of the total water in the sauce so hardly enough to make any noticeable difference.  In fact, not even enough to make a significant difference in the ¼ of water that was used to transport it from the pasta pot to the sauce! 

¹  See Wolke's article in the Washington Post here

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Due to the volume of questions received, not all can be answered.
© Lost Hobbit Enterprises 2004 onward

Difference Between Salsa and Pico de Gallo

What is the difference between salsa and Pico de Gallo?  They seem to be used interchangeably on restaurant menus.

--Denise

Salsa is the Mexican word for "sauce".  It can include both cooked salsas, like those found on supermarket shelves across North America, or "Salsa Cruda", meaning uncooked sauce.  A salsa cruda is typically prepared from fresh ingredients shortly before serving, although it will last refrigerated for several days and the flavor can become more blended and complex if it is allowed to rest for several hours before being used.

Salsa is usually made from sweet and hot peppers, onions, tomatoes and/or tomatillos, garlic, and cilantro, seasoned with salt and possibly pepper.

Pico de Gallo [pronounced Pee' Koh de Gah" Yoh] means "rooster's beak".  According to The New Food Lover's Companion, the name may refer to eating Pico de Gallo by picking it out of the bowl with thumb and fingers.  While Pico de Gallo may be made using similar ingredients to salsa, it may also include cucumbers, tropical fruits including mango or pineapple, corn, or other ingredients not typically found in other salsas.  While it may be considered a form of salsa, Pico de Gallo may also be drier than cooked or fresh salsa.

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Due to the volume of questions received, not all can be answered.
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Getting Your Juices Flowing

What is the purpose of drawing out all the juices from a piece of meat with salt just have to have them all reabsorbed again.  To me, this doesn't make any sense.

--Linda

I mention this process in the posting Salting Meat Before Cooking.  It is also part of the working of dry rubs containing salt that are used on meat.

There is some benefit from simply having the liquid reabsorbed, since it will make the meat more moist, but the real benefit is that the salt dissolved with the juices is absorbed at the same time.  The salt both seasons the meat, enhancing flavor, and causes the meat proteins to absorb more water, resulting in a juicier, more tender dish.

Because it takes a long time for salt to penetrate, this is mostly surface phenomenon in the case of salting just before cooking.  Dry rubs may take hours or even days for the salt to fully penetrate the meat.

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Due to the volume of questions received, not all can be answered.
© Lost Hobbit Enterprises 2004 onward

Bundt Strike Out

I have a "non stick" Bundt pan but of course I grease it every time, usually spray it with baking spray until it can't take anymore, then do it again before I put the cake in.  For some reason though, the past couple times the cake has been glued to the sides of the pan and I ultimately had to scoop it out of the pan and call it a crumble cake. Is there a better way to do this?

--Abigail

I am guessing that the problem you have is a build up of dried oil on the inside of the Bundt pan that is now making it more like super-stick rather than non-stick.  I have seen this happen with cooking sprays on non-stick frying pans.

If you have ever seasoned a cast iron frying pan, you might have noticed that once the pan cools down the oil has turned from a liquid to a thick, gummy or even hard surface.  This drying effect is caused by the oxidation of specific bonds in the fatty acids that make up the oil.  This results in cross-linking of those fatty acids which in turn makes the oil either harden into a film or turn thick and gummy.

Several factors can influence the amount of oil that builds up from your spray, including the type of oil in the spray, the amount used and the temperature at which it is used.  It is recommended that only a very light layer of spray be used, as shown in the video below.  From your description, you are using quite a lot more spray than is recommended. 

Also, you need to be sure that you are using a spray that is specifically designed for baking and one that contains flour as a releasing agent.  Regular cooking spray will not work properly.

Unfortunately, once you start to get a film of oil there is probably no way to return the pan to its original non-stick condition.  Any effort to remove the extra layer will likely damage the non-stick coating underneath.  You might try using it as if it was a normal (not non-stick) pan by coating it with butter or vegetable shortening and then dusting it with flour and shaking out the excess.  If that doesn't work, the pan is likely destined for the dustbin.

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© Lost Hobbit Enterprises 2004 onward

 

Tying Roasts Together to Cook

I have 3 bottom rounds of beef that weight an average of 13 pounds each. I want to tie them together to cook. My recipe, which is for a steamship roast, is 5 minutes per pound at 500 degrees, then turn oven off for two hours then turn oven on again at 300 degrees for 45 minutes for medium to well done.

My question is do I cook them for the combined weight time or do I cook them for the time of the largest roast. If the combine weight is used, do I need to adjust this time?

I am tying the roast together for the purpose of making them fit into the oven.

I have already posted the answer to cooking two roasts at once if they are not tied together (see Cooking Two Roasts at Once), but when they are being tied the question is a lot harder to answer.

The common guideline for how much time that it takes to cook a roast is minutes per pound.  According to McGee (On Food and Cooking: The Science and Lore of the Kitchen), however, the time is more accurately proportional to the square of the thickness, or the weight raised to the ²⁄3 power.

What do these numbers mean?  Start with thickness.  If a roast of some given thickness takes, say, 1 hour to cook, then if you double the thickness, it should take 2² = 4 times as long or four hours to cook, and if you triple the thickness, it will take 3² = 9 hours. 

Now if you go by weight, what the formula tells you is that smaller roasts take more time per pound than do larger ones.  You have likely seen this if you have looked at suggested times to cook a turkey.  An unstuffed eight pound (3.61 Kg) turkey will take about 2 ³⁄4 hours, or about 20 minutes per pound (0.454 kg).  An unstuffed 24 pound (10.9 Kg) one will only take about 5 hours or 12 ¹/2 minutes per pound.

Obviously there is something wrong with these two estimates, given that in one case the time is rising wildly, while with the other it is decreasing in minutes per pound.  The reason is in part because the estimate based on thickness uses the mechanics of heat transfer and only looks at one dimension, so it ignores the heat coming in from the other sides of the roast, and also because you seldom get a roast that is twice as thick as another but measures the same in the other two dimensions.  In other words, the weight increases as something like the cube of the thickness, so on a per unit weight basis that roast that is three times as thick will weight something close to 27 times as much (3³ = 27) and the cooking time per unit weight is ⁹/27 or ¹/3 as long.

Estimated cooking time depends, of course, on a large number of other factors.  These might include how accurate the oven thermostat is, what material the roasting pan is made from and what color it is, the internal temperature of the meat when you start roasting it, and so on.

To make matters even more complicated, your recipe isn't at constant heat.  The two hours rest in the oven with the heat off is completely unpredictable in terms of how much the oven will cool down during that time.  There is simply no way to predict accurately how long it will take, since the amount of time depends on the shape of the roasts and how you end up tying them together.  I would suggest using the recipe as stated as if you were cooking a 40 pound roast, but use a meat thermometer to see how well done the tied together roast is getting, and be prepared to eat a lot earlier or later than you planned.

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Due to the volume of questions received, not all can be answered.
© Lost Hobbit Enterprises 2004 onward

 

Defrosting Frozen Turkey

How long does it take to defrost a frozen turkey?

--Andy

The length of time it takes to defrost a frozen turkey depends on a few things, most importantly the weight of the bird and the method used.  The length of time will also be affected by the temperature at which it is being defrosted.

There are two generally accepted ways of defrosting a turkey that are considered safe.  The best way is to place the whole bird in your fridge and defrost it slowly.  Using this method, it will take about 5 hours per pound, or 10 hours per kilogram.  The exact length of time may be a bit shorter or longer, depending also on the temperature of the frozen bird and the temperature of the refrigerator.  Since the thawed bird can remain in the fridge for a day or two after it is defrosted, it is better to give yourself some extra time, if possible, rather than not thaw it long enough.  It is recommended that you place a large pan under the bird so that any juices that leak out are caught in the pan rather than dripping onto any food on a lower shelf.

Alternately, if you are short of time, or if the turkey hasn't completely defrosted in the fridge, you can try defrosting it in a bath of cold water.  The water must be kept at or below 40°F (4°C), and the bird must be completely submerged.  Run cold water into a large basin or sink and place the bird, still in its packaging into the water.  If you have a probe thermometer, you may be able to use it to be sure the water remains cold.  Because water is a better heat conductor than air, this method is somewhat faster than using the fridge.  Depending on the size of the basin or sink, defrosting should take about 30 minutes per pound or one hour per kilogram.

Methods that are not recommended are thawing the turkey in your microwave, assuming you have one that is big enough, or thawing at room temperature.  Both of these methods increase the risk of food borne illness.

To read about how long to cook the turkey, see Roast Turkey Temperature.

To read about keeping leftovers, see How Long will Leftover Turkey Keep in the Fridge.

And to read about food safety for stuffing, read Dis-dressed Turkey.

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Due to the volume of questions received, not all can be answered.
© Lost Hobbit Enterprises 2004 onward

 

Weighing In

My new kitchen scale has a button labeled "Tare".  I'm not sure what it is for or how to use it.  Can you help?

--Tandi

The 'Tare' button, sometimes labeled as a 'Zero' button, is used to reset the scale to zero.  It can be used in a number of ways.  The simplest is to make sure that the scale is actually reading zero.  When you turn on your scale to use it, it will sometimes not read exactly zero.  Pressing the 'Tare' or 'Zero' button will set it to zero.

Now, suppose you want to weigh an ingredient, maybe a piece of chicken breast or the amount of pie filling you have.  Obviously for health or clean up reasons you don't want to put it directly on the platform of the scale.  Instead you might put a measuring cup or a bowl onto the scale to keep it clean.  Now the scale shows the weight of the container.  Rather than having to do the math by hand, if you press the 'Tare' button the scale will read zero again, having subtracted the weight of the empty bowl from the reading, and you can go ahead and weigh the ingredient.

For some recipes, like making bread using Baker's Percentages, you want to weigh a number of ingredients in succession into the same container.  In that case, you can weigh the first ingredient, press 'Tare' to set the scale to zero again before weighing the second, press 'Tare' again, and so on until all of the ingredients have been added.

Another use for 'Tare' is when you are measuring something off of a larger chunk.  Suppose, for example, that you need 4 ounces by weight of grated cheese.  You could try to guess how big a four ounce piece would be and cut it off the larger block before grating it.  Or, you could grate some cheese, put it into a bowl on the scale to see if you have enough and keep going back and forth until you have the four ounces you want. 

Somewhat easier and a lot more convenient is to weigh the whole block of cheese and then press the 'Tare' button.  The scale will read zero, and when you take the cheese off, it will show the weight again, but this time with a minus sign ('-').

Now go ahead and grate the cheese,  When you think you may be getting close to the amount you need, put the whole block back on the scale.  The weight shown will be the amount that you have removed from the block, again with a minus sign in front.  If necessary, grate some more and reweigh  until the scale reads minus four ounces.  This is easier since you don't need to stop to move grated cheese from the work surface to a container.  You will likely also get fewer dishes or utensils dirty that you then need to clean afterward. 

Note that if the number shown when you weigh the block is less than 4 (ignoring the minus sign), you need to grate more.  If it is larger than 4, you have grated too much.  The first few times you use this method, you may need to think it through before it makes immediate sense, but it works.

The only challenge with the last use for the 'Tare' button is that most electronic scales have a time-out which turns the scale if if it is not used in a minute or two.  You need to be faster than the time out, or just put the block back onto the scale to reset the time-out timer.  Worst case is it times out and you either need to remember how much you started with and do the math by hand or you need to weigh the final amount of grated cheese.

For those who are incurably curious, the word 'tare' comes from an old Italian word 'tara' which in turn came from the Arabic 'tarha' meaning 'that which is removed'.

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Due to the volume of questions received, not all can be answered.
© Lost Hobbit Enterprises 2004 onward

Give It a Rest

Why should you rest meat after cooking it?

-- Darren

Resting meat serves three purposes.  First, it allows the meat to finish cooking through,  Straight out of the oven, or off the fire, the outside of a piece of meat is hotter than the middle.  The difference in temperature can be quite large.  During resting, the heat from the outside penetrates to the middle, finishing the cooking of the interior.  That is why many recipes call for taking a roast or whole bird out of the oven when the temperature read on a thermometer stuck into the middle of the meat is actually a few degrees lower than what is desired.  The meat finishes cooking outside of the oven because of the carry over cooking.

Second, allowing meat to cool allows the collagen and connective tissue to firm back up again, making slicing easier.  See the posting Slicing Roast Beef, where this was discussed.

Finally, according to Harold McGee in On Food and Cooking , as the meat cools, its water-holding capacity increases, meaning that less juices will be lost during cooking or drain out of the meat once it is on the plate.

The length of time that the meat should rest depends on the type of meat and its thickness.  For smaller pieces of meat 5 to 10 minutes may be enough.  Large roasts may be rested 1/2 hour to a full hour, or sometimes even longer for very large pieces.

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Due to the volume of questions received, not all can be answered.
© Lost Hobbit Enterprises 2004 onward

Blowing Smoke Rings

When I barbecue meat, there is a layer just under the surface that doesn't look like it got cooked, even though the middle looks done.  What causes that?

-- Dean

What you are seeing is called the smoke ring.  It is an area of meat that, although it is cooked, hasn't turned the greyish brown we associate with cooked meat.  There are actually two different causes for meat to still be red, despite being cooked, both of which relate to the oxygen carrying protein myoglobin found in meat.

When you barbecue, the burning wood, charcoal or gas produces trace quantities of nitrogen dioxide (NO₂) as one of the combustion byproducts.  The nitrogen dioxide combines with water molecules to a form mild acid called nitrous acid (HNO₂).  The water molecules may be on the surface of the meat, in the air surrounding the meat, or as another byproduct from the burning of the fuel,  In any case, the nitrous acid that comes into contact with the meat slowly penetrates the surface to a depth of up to ½ inch (12 mm) or so, where it comes into contact with the myoglobin, replacing the oxygen atom that is attached to it with nitric oxide (NO).  The effect is the same as using nitrates to make sausage or other preserved meats.  The red color of the myoglobin is locked in, causing the pink color to remain.

The formation of a smoke ring can be enhanced in several ways:

1. Keep the temperature as low as is safely possible, around 200°F(93°C).  This will keep the surface of the meat from drying out, thus providing more moisture for the above reactions and keeping the outside tender so that the nitrous acid can penetrate.  It also slows down the rate at which myoglobin denatures from heat and can no longer react with the nitric oxide.
2. Add moisture to the cooking environment by placing a pan of water in the barbecue.  This has two advantages, one being more moisture for the reaction and the other that the water acts as a bit of a heat regulator, keeping the temperature close to the boiling point of water.
3. Don't dry out the surface of the meat before cooking.  Most recipes are looking to have the surface dry so as to encourage the Maillard reaction (see Browning Meat for Slow Cooker).  In this case you want to leave the moisture on.
4. Where you would usually allow meat to warm to room temperature before cooking, going straight from fridge to fire will lengthen the amount of time it takes for the myoglobin to become denatured.
5. Finally, the nitrogen dioxide is a result of poor combustion.  I don't recommend fiddling with your gas barbecue, but if you are using wood, you want lots of smoke.  Not only does this help flavor, it also increased the amount of NO₂ produced.

A similar effect to smoke ring is caused by slow cooking where the temperature is low enough that the other proteins in the meat, except for the myoglobin, denature first.  Once the myoglobin starts to denature, there is nothing left for it to react with and the color stays.  This is why confit of duck legs remain pink inside after long slow cooking, or why the meat in stews can sometimes remain red.

Finally, there is a way to fake a smoke ring, by sprinkling the surface of the meat with a small amount of a tenderizer or meat preservative that contains nitrates and leaving it for an hour or so before rinsing and cooking.  Morton's Tender Quick is frequently mentioned for this less authentic method.  Barbecue aficionados are divided on whether this constitutes cheating.

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Due to the volume of questions received, not all can be answered.
© Lost Hobbit Enterprises 2004 onward

When to Correct Temparture for Altitude

I have read your earlier post on high altitude cooking, but was wondering whether I should always correct the temperature for the altitude that I'm at, or just in some circumstances?  Do I cook a holiday turkey to the same temperature or correct it for altitude?

--Shoshana

As noted in the post on High Altitude Cooking, the boiling point of water drops by about 2°F (1°C) for every 1,000 feet (300 meters) increase in altitude, above sea level.  For those dishes where there is some direct relationship to the boiling point of water, for example in cooking sugar to make syrups or candies, the temperature at which events occur happen sooner because water boils at a lower temperature.  In candy making, a recipe might call for cooking to the 'hard crack' stage, which occurs at between 300°F (149°C) and 310°F (154°C).  At 2,000 feet altitude, that same stage is achieved about 4°F or 2°C lower, so the range is 296°F (147°C) and 306°F (152°C).

However, when making a custard or cooking meat, the temperatures relate more to  those at which certain reactions occur with proteins.  These temperatures are independent of the boiling point of water where you are.  When making custards and sauces, the protein molecules will start to denature and begin to bond with each other somewhere around 120°F (50°C).  This process will continue up until about 180°F (82°C), at which point the proteins will become overcooked and the dish will curdle.  These temperatures will vary depending on what other ingredients are used. 

If you use a bain-marie, it takes longer for a cheesecake to cook at higher altitude than it does at sea level because the water in the surrounding water bath evaporates at a lower temperature.  This in turn means that the cheesecake is cooked at a lower temperature and therefore takes longer to heat through enough for the eggs in it to set.

When cooking your holiday turkey, the temperature you are looking for is the balance between food safety, killing any nasty bacteria that can make you sick, and cooking the meat to the point where the connective tissue breaks down, proteins haven't started to over cook and collagen melts.  The minimum temperature for that is 165°F (74°C), regardless of altitude.

For that holiday turkey, you need to cook to the recipe directions, regardless of altitude.  The same applies to any roasted meats, whether turkey, chicken, beef, pork or anything else.

Where all of this gets really tricky, though, is in baking where some of the reactions depend on the boiling point of water and others don't.  If you look at altitude corrections for baking, they typically decrease the amount of sugar and increase the amount of water in order to allow the other reactions, gelatinization of starches and coagulation of proteins, time to occur.  Typically, they also decrease the amounts of leavening (baking powder or soda) so as not to have the product over-inflate. 

So, baking whether cakes, custards, cheesecakes, and so on, require special attention and can take longer at higher altitudes. Recipes where sugar in cooked such as in making candy, need to be corrected for the affect of altitude on temperatures, but for roasting you should still aim for the same temperature as at sea level.

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Due to the volume of questions received, not all can be answered.
© Lost Hobbit Enterprises 2004 onward