How to keep my (deep frying) oil usable as long as possible?

Question

I have a new deep fryer. I am pleased with its results so far. I am not a 'heavy user' though - say once every 2-3 weeks. I want to re-use the oil a couple of times. The deep fryer is covered but not airtight, however.

The new deep fryer has a cold zone, which means the oil won't become dirty due to particles over-frying. I don't overheat the oil either. So, in principle, I'm frying correctly, I think.

So, how long can my oil safely sit in the deep fryer, if I ensure it's thouroughly heated next time I fry? Should I be allowing the oil to cool and store the fat in (sealed) containers instead, if there's going to be this long a gap between uses?

Edit: yes, I've seen this question and answers: http://cooking.stackexchange.com/questions/3014/frying-oil-reuse

Asked by Tobias Op Den Brouw

Answer

First thing, a cold zone doesn't prevent particulate build up, it just cuts down on the amount that will remain suspended in the oil. You should still filter if you want to keep your oil as long as possible. You can detect bad oil (meaning rancid) by a few ways, like smoke point or smell.
You should store your oil someplace dark and cool, which could be the inside of your fryer as long as you filter and clean the sides before you stick the oil back in. Another thing you can do to extend the life of your oil is switch to tallow (beef fat) or rended pigs fat (lard) as saturated fats do last a lot longer than the poly-unsaturated.

Once again, you should lose the oil when the smoke point drops, or if it is to dark, or if it develops any foul odor. And as I said before, once you use the oil once, you should NOT use it past six months under any circumstances, if you do, you are taking your gastro-intestinal tract into your own hands.

Answered by sarge_smith

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Refrigerate Cod After Cooking

Question

Is it okay to refrigerate Cod (and other kinds of fish) once cooked and eat the next day?

If so, can you reheat it before eating?

Asked by Chris Diver

Answer

Yes, it's fine to refrigerate cooked fish. Many types of fish are excellent (better, even) served cold -- shrimp and salmon are good examples. If you can eat it cold, it's hard to see how reheating would pose any additional risk.

There are some other considerations, though. It's easy to overcook fish, which leaves it dry and less than tender, and that goes double if you're reheating. Use low heat (or low power in a microwave) and be careful not to cook too long. Some sauce will help keep the fish reheat, but avoid storing the fish in a strongly acidic sauce (like lemon juice) as acid will change the fish over time even in the fridge. And avoid reheating fishy things in the microwave at work if you value your relationship with your coworkers -- the smell often lingers.

Answered by Caleb

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Can cashews go bad? If so, how do you tell?

Question

We have a tub of cashews that seems "off:" they smell a little different and taste a little different than we're used to.

They don't smell or taste rancid (to us, I don't think I've ever tried cashews that were old enough to possibly be rancid) but I'm wondering if there can be any other type of degredation in them. e.g. I've read that peanuts can get a sort of mold growing on them that's not good for you.

Asked by Ward

Answer

It is possible for mold to form on cashews - or any other nuts - but only if there has been moisture penetration into the container. If the moisture is at a safe (low) level, then mold won't grow.

See for example, Mycology and spoilage of retail cashew nuts, which refers to the maximum acceptable moisture content of 5.8% for retail storage/shipping, although if you look at their data table, it appears that you may still end up with non-trivial amounts of mold in the low 5% range (which is why you are supposed to store nuts sealed and in a cool, dry place).

Honestly, cashews are hard enough such that you would almost certainly see mold on the surface if it were present in harmful quantities. Most likely what you're smelling/tasting is simply oxidation of the fats (the process which causes rancidity) without actual full-blown rancidity. Mold requires moisture but all oxidation requires is light and maybe a little air exposure.

If you really want to be on the safe side - e.g. if your home is particularly hot or humid - then store your nuts in the refrigerator or freezer (sealed, to prevent contamination or off-odours). Although most (all?) nuts are considered shelf-stable, they do keep longer in the fridge or freezer.

Answered by Aaronut

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Is it safe to store hot tea in PET bottles?

Question

Every morning I bring with me a small PETE (from some searches it seems to be the same as PET plastic) bottle (an ex coke bottle) containing hot tea.

1. Is it safe to store hot liquids, especially, tea in this type of container?
2. Is possible, under these conditions, that the bottle releases some harmful substances?

Thanks in advance.

Asked by iRubens

Answer

Live and learn, I was writing about PET causing cancer, but that's a hoax, apparently.

Some plastics can stand heat better than others, so try to be on the safe side, and let the liquid cool to 50°C (122°F) before storing it.

No, it won't release any harmful substances.

Answered by BaffledCook

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What is the danger of salmonella in 'home laid eggs' and how should I clean them?

Question

I have a question additional to this question How does salmonella get into eggs. This tells me that salmonella is mostly found on the shell of an egg. However, eggs are treated (typically washed) such that most egg shells do not contain any salmonella anymore.

I eat eggs which I get from my mother-in-law who has her own chickens, so these eggs are not 'treated'. I was wondering a few things:

• What is the risk that these eggs contain salmonella? Is this risk negligible?

• Should I use supermarket eggs to make food with raw eggs in it, for example chocolate mouse, and only use these eggs for food which is heated?

• If there is a risk, how should I clean the shells? (using hot water is not an option for eggs, of course).

A related question might be Is it safe to eat raw eggs?. The answer seem to be yes, but here it also seems that it is about 'supermarket eggs'.

Asked by Lotte Laat

Answer

The danger of bacterial contamination is much lower in home laid eggs than in commercially produced eggs exactly because of the washing process that eggs go though in the US.

See the accepted answer to this question:
How long can I keep eggs in the refrigerator?

Eggs are naturally laid with a protective coating on them that will keep out bacteria. An egg keeps for a long time in a nest after all.

Commercially produced eggs are washed- I assume for cosmetic reasons- which destroys this coating and makes the porous egg shells very susceptible to bacteria.

You should discard eggs that have damaged shells but other than that you can consider your mother-in-laws eggs much safer than any you could get at the supermarket.

Answered by Sobachatina

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Which foods generally create a problem of gas or acidity? [closed]

Question

I am found of eating various dishes. But I have a gas problem, a little heavy food will create gas. So I need to be very conscious about my eating habit. So, which cares I should take while cooking food and selecting items to cook.
One thing I would like to say is I am Indian so I will prefer Indian dishes more.

Asked by Himadri

Answer

I'm sure you already know this, being Indian, but adding a small amount of Asafoetida, which is widely used in Indian cuisine, to your dishes will work wonders. It works as a digestive aid and will reduce flatulence.

Typical causes of flatulence are beans, lentils, onions, garlic, cauliflower and a few others. Acid is typically caused by high fat foods, such as dairy products. Also fruits with a high citrus content can cause problems. The one that always gets me is coffee, I love it but it hates me.

Answered by Pulse

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Sugar for babies food [closed]

Question

Is it true that adding sugar to babies under one year food are not safe? If so what can I use instead of sugar to make healthy and tasty food for my child.

Asked by Soss

Answer

I know that one shouldn't give honey to infants because their immune systems aren't developed enough to deal with the C. botulinum spores found in it, but I've never heard that table sugar was unsafe for them. That said, some pediatricians believe that adding sugar to baby food encourages an unhealthy taste for sugar in children and should be avoided. The natural sweetness of fruits and vegetables should be enough flavor for infants, particularly because they haven't yet developed a taste for table sugar that might interfere with their enjoyment of food.

Answered by Iuls

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What method for advance prep of seitan prevents deterioration of texture and preserves flavor while protecting from spoilage?

Question

Tonight, I am hoping to cook up three to four loaves of seitan for final prep three days from now. My intent is to form the dough, simmer in stock or steam, and then refrigerate. In three days I hope to use the seitan to make sandwiches after bringing up to temp while smoking on the grill and then slicing.

I have seen storage options including freezing, refrigerating wrapped in cling wrap, refrigerating while submersed in the simmering liquid, and a few variations in between. Three days is long enough that I would be concerned about spoilage, as well as picking up stray odors (I will be doing a bunch of bulk cooking of different foods). It is at once short enough that I don't think the texture would necessarily be compromised, but definitely see it as possible if stored in liquid. Likewise, flavor will last fine, but if it is in a simmering liquid, that is soy based, I am concerned it would leech every drop of saltiness and end up as some decaying, more-spongiform-than-usual, briny bread.

So I am looking for three possible things and the benefits/drawbacks of any methods;

• What advance cooking method will work for a batch that will be reheated by smoking (low heat for about an hour or two)?
• What storage method will preserve texture, maintain flavor, and lock out nasties?
• What steps can I take when re-heating to preserve all of the above effort?

Essentially, what is the prep/storage/plate combo that will save me from turning a few pounds of simmered vital wheat gluten into cloudy clods?

Asked by mfg

Answer

hmm....

my thoughts:

1) biologists use stock as a medium for growing bacteria. therefore, anything stored in stock; I generally like to boil/heat up a lot first before eating

2)the seitan should stay just fine; kept dry in the fridge in an airtight container

3) have you tried making steamed seitan, ala seitan of greatness from lachesis?

4) have you tried making "dry" seitan in a water bath (bain marie) in the oven: this is how it is done in the rfd (real food daily) cookbook. I make this a lot; both the "chicken" and "basic" (which reminds me of turkey)

Answered by Jill Renee

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leaving oil on a frying pan for use later

Question

I live alone, so I cook for myself. And often times I cook steaks/burgers on a pan, and later in the same day would return to use the same pan/oil without washing/using new oil.

Is this safe, or should one wash and use a new pan before cooking every steak/burger patties? I've actually done this for more than a day once (cooked burgers in the morning, steaks later that afternoon, and then burgers for the next morning).

Asked by kamziro

Answer

If you preheat the pan then you should be perfectly safe as the high heat should kill anything 'dangerous' before you add your meat for the second meal.

That said, I would point out that those oils left out are likely to begin to degrade immediately, causing your steak to take on some potentially undesirable FLAVORS.

Answered by Cos Callis

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Is it safe to eat sprouted onions?

Question

I opened my onion rack lately to find onions that had sprouted several-inch-long green roots... It made me extremely queasy and I threw them out. But I was wondering - would it be safe to eat them / cook with them?

Asked by clueless

Answer

Sure, but the rest of the onion gets mushy and unpalatable after they've grown for a bit. Some people eat the sprouts; they have a lot of protein, so they're popular with vegans and other protein challenged groups.

Answered by Satanicpuppy

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Does microwaving eggs kill salmonella?

Question

If eggs are thoroughly washed and of course beaten before microwaving, and after the process I can find no liquid, is there a possibility that salmonella is still there, or does it die from high temperatures?

Asked by Septagram

Answer

Microwaves do not kill bacteria, heat kills bacteria. The higher the temperature, the faster those bacteria will die off.

"Instant death" for most bacteria (including salmonella) is about 160° F (71° C). You only need a few seconds at this temperature. The notoriously strict USDA recommends 160° F for egg dishes but is considerably more lax about whole eggs and just says to cook until firm. Very few eggs are contaminated in the whites or yolks, so the risk is very low.

Pasteurization begins around 57° C (135° F), so many bacteria are killed before the egg coagulates (at 63° C / 145° F), which is why the USDA is not very strict about it; if an egg by itself is "firm" then it's generally already been hot enough for long enough to ensure safety.

Unfortunately, microwaves tend to heat (a) quickly and (b) unevenly, so if you are concerned about food safety and insist on making eggs in the microwave (not recommended), be sure to use short bursts and stir several times, otherwise you might end up with a combination of uncooked and overcooked parts, which is bad for food safety and for general taste and texture.

Note that there is not only a possibility but actually a certainty that some salmonella is still there, assuming that there was any to begin with. Cooking is equivalent to pasteurization and that does not kill every single bacterium, nor is it meant to; it just kills about 99.9999% of them which makes the cooked item safe enough to consume.

Answered by Aaronut

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Can I boil eggs in the same pot I'm boling something else?

Question

I know cooking the eggs kills the salmonella and that the risk is small even for raw eggs. However, I stopped boiling the eggs in the same pot I'm boiling something else, like potatoes, when I learnt the salmonella is in the shell.

Obviously, I'm not eating the shell and the eggs are washed. I wonder if I can boil everything in the same pot or not.

Asked by Julio

Answer

I personally reckon it's fine.

Couple of points I like to make here are:

1. Hygiene of eggs: Make sure you wash your eggs before you cook as surface of egg can be very dirty
2. Maybe put the eggs in with cold water, otherwise, put the eggs when the water is hot may crack the eggs

Answered by Foodrules

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Safety of coffee in thermal flask, long periods of time

Question

How long is it safe to hold coffee in a thermal flask? Is coffee (prepared in a cezve, Turkish method, no sugar) carried in a thermal flask for 24 or 48 hours still safe?

I'm asking because black tea, for example, goes really bad in just a few hours.

Asked by Mischa Arefiev

Answer

Coffee in a container is approximately as safe as boiled water in a container. While it may be unpleasant tasting, the water in coffee and tea is almost universally boiled, and the scalding liquid is placed directly on the grounds/tea leaves. There is a little nutritional value in coffee and tea extracts, providing some support for new microbes introduced after the boiling, but not much.

There is no reason to be wary of coffee kept in a clean, sealed container for a day.

Answered by Myrddin Emrys

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Does grenadine need to be refrigerated?

Question

I've been looking for a bottle of Rose's Grenadine for quite a while without luck, so when I saw a big ol' liter of Llord's at the liquor store, I grabbed it. I'm not sure I want to allocate that much fridge space to it though. Can I keep it behind the bar instead?

Sugar is a preservative and there's a little bit of alcohol in it too, so my guess is it's ok on the shelf.

Asked by adambox

Answer

I'm not sure about other types of grenadine, but assuming they're the same as Rose's, they do not need to be refrigerated.

It's not just that they contain sugar - they're practically nothing but sugar, water, and a couple of "chemicals." There's really nothing in there that can spoil, unless you put something else into the bottle that wasn't there originally.

Unless you accidentally dropped a piece of chicken in there, definitely don't worry about refrigeration. It can sit on the shelf.

Answered by Aaronut

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How long can eggs be unrefrigerated before becoming unsafe to eat?

Question

A friend of mine accidentally left a carton of eggs on her counter, unrefrigerated, for three days. The eggs had been previously refrigerated both at the store and at home. Now she's planning to do some more cooking which requires eggs, and is wondering if it's still safe to use them for baking. I believe she is planning on baking cookies with them, so they would be baked at fairly high temperatures for probably at least 10 minutes. Would this be safe, or are eggs left unrefrigerated for that long not safe for consumption?

Asked by nhinkle

Answer

The FDA, generally on the very safe but a bit paranoid end of the spectrum, says:

After eggs are refrigerated, they need to stay that way. A cold egg left out at room temperature can sweat, facilitating the movement of bacteria into the egg and increasing the growth of bacteria. Refrigerated eggs should not be left out more than 2 hours.

(They also say some very sad things about Easter egg hunts.)

So if you're being strict, three days would be way too long. In reality, you'd probably be okay. The chances of getting salmonella are definitely higher, but are presumably still small (though I can't say exactly how small, of course). Personally, given the price of a dozen eggs, I'd probably play it safe.

Another answer mentions that in the UK eggs are stored at room temperature. That's true in quite a lot of places, but I'm guessing that they've avoided the large temperature swing issue mentioned by the FDA, so if your friend's eggs were refrigerated in the store, the situation's not quite the same as in the UK.

Answered by Jefromi

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Cooked whole chicken has congealed blood around joints and bones, should I worry?

Question

So I just roasted a whole chicken and finished carving/cleaning the carcass today. I discovered a great deal of congealed red matter surrounding many of the joints and bones. Looks like congealed blood. Normally, I wouldn't worry about it, except that there's a lot more of it than there usually is. And it's a brighter red, as opposed to the dark reddish brown I'm used to. Should I be worried? Did I undercook the chicken? Was this chicken just not as well drained as ones I've gotten previously?

Asked by Daniel Bingham

Answer

This exact thing happened to me about a month ago - roast whole chicken, bright red leaky blood around the bones and joints.

I looked it up back then. I didn't find a truly authoritative source like the USDA, but I did find several instances of people saying that this happened even with highly overcooked chicken. I also found several links similar to this one:

Bloody Chicken

The author (a Ph.D according to that page) did a number of experiments where he cooked a chicken and checked the internal temperature everywhere, ensuring that it was in fact pasteurized and thus free of any bacteria, and parts of it were still bloody on the inside.

According to him (and a few other sources I found), it's because the chickens are very young and their bones have not hardened properly; when you cook them, the marrow seeps out and ends up looking as you describe.

If you're using a meat thermometer to test the chicken for doneness, and you are certain that it got hot enough, then don't worry about the blood. It's not appetizing, but it's not harmful either.

FWIW, I ate the chicken when it happened to me, and did not get the slightest bit sick.

Answered by Aaronut

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How long can hard cheeses last in a refrigerator?

Question

I had chunks of various hard cheeses, mostly parmesan, in my refrigerator for varying lengths of time. Some as long as 3+ months.

I've never seen any obvious signs of spoilage and have never been struck down by food poisoning after using said cheese. But my wife is very suspicious when using any food that has been in the fridge for longer than a week.

Is there a generally accepted length of time to keep these types of hard cheese?

Asked by rageear

Answer

Hard cheeses (e.g. parmesan) will typically last several months in the refrigerator once removed from the packaging. The larger the chunk, the longer it will last. If mold forms on the outside, simply cut it off and continue using. There is no reason to throw-away good parmesan.

Answered by Jonathan

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Reconciling Food Safety Tips: Food vs Water

Question

I've never understood why water found in the wild should reach a temperature of about 200 to be safe, but food leftovers only need to reach 165 to be considered safe. Does someone know the reason for this difference?

Asked by Myrddin Emrys

Answer

165F will kill many things and leave meat proteins very tasty. That is why it is the recommendation for meat.

Water doesn't burn when heated past 165F. And if heated to boiling (212F) not only will it kill more things faster but it is easier to tell when you get there. Who carries a thermometer with them when they go hiking?

Answered by Sobachatina

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Are there health issues with sous-vide cooking?

Question

As I understand the technique, you put a food item in a plastic bag and dump it into warm water for some amount of time.

What happens to bacteria growth inside the bag?

Asked by BaffledCook

Answer

If you do it properly, no there are no health issues.

A combination of two things are required to kill beasties: heat and time. The higher the heat you expose them to, the faster they die. Generally any temperature above 130 F is enough to kill most beasties, it just requires a significantly larger amount of time compared to a higher temperature.

I go into a lot of detail regarding Salmonella in this answer of mine:

http://cooking.stackexchange.com/questions/4292/is-it-safe-to-eat-a-cooked-steak-that-briefly-touched-the-plate-that-was-holdin/4307#4307

I have several tables there to show exact timings, etc.

_{If you think I should copy/paste that here, then let me know in a comment}

Answered by hobodave

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Are chilies in olive oil dangerous?

Question

In Portugal, chilies in olive oil are a very typical form of spicy sauce, in both commercial and artisan forms. Different types, amounts, and mixes of chillies result in different flavours and it can be very nice.

However, I worry about botulism. I have googled for this and find many warnings against preserving garlic or other spices in oil, but nothing related to chilies in particular.

Are chilies different?

Or are the commercial chili olive oils prepared in a way that makes them safe? Any way to achieve the same at home or should I just stick to the industrially prepared products?

Asked by luispedro

Answer

There's nothing magical about garlic that causes it to be especially prone to botulism - it's just commonly found as an example because it's commonly used to prepare flavoured oils.

All low-acid foods must be acidified or pressure-canned before long-term storage. Storage in oil creates an anaerobic environment which further promotes botulism, and room-temperature storage is even more risky.

Chili peppers are low acid, like all peppers, so yes, they're a risk.

Answered by Aaronut

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