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Keep in mind that the luggage compartment isn't temperature controlled, so whatever you're bringing back should be packed to withstand temperature fluctuations, and not be spoiled by the variations.

I once had a bottle of conditioner curdle during its trip in the checked luggage. No idea what caused it, but it was fine when I left and it was cottage cheesy when I got where I was going. Not a great loss, but it was weird, and it makes me think twice about packing anything that might spoil -- and be expensive.

I've never done it when traveling to another country, but I've done it flying from state to state.

Now that I think about it, whoever inspects my luggage must think I'm a total freak. Last Thanksgiving when I was living in Arizona, I packed two massive cookie sheets in my bag because I knew my parents didn't have any and I was the one doing all of the cooking.

This past summer I was visiting my boyfriend in Alabama and I brought all kinds of food-related items in my luggage; spices, sushi rice, vinegar. I was going to cook for him and tracking down all of that stuff in the small town where he lives seemed like too much of a pain in the ass, so I just packed it all. I did have a paper in my luggage telling me that my bag had been inspected, but that was it.

It's U.S. Customs you need to be concerned with -- the TSA is only worried about whether the items in your luggage are a hazard to the flight (e.g., flammable, explosive... think terrorism, mid-air accidents, etc.).

Customs is concerned with items that are subject to duty, potential public health risks, trade banned goods, etc. In general, agricultural products are going more closely scrutinized and have tighter restrictions. This may or may not include dairy, depending on the type and its origin. Certain types of meats are never ever permitted, even if they are canned or otherwise preserved (e.g., certain hams, pates, etc.). The rules and restrictions on produce and plant materials are very tricky, and may be even more restrictive when entering through certain states (e.g., California's agricultural restrictions are stricter than most). If you actually visited a farm to obtain any of the goods, they'll want to know that, which will lead to a detailed interview, at the very least. Relates to concerns about BSE, avian flu, etc.

Definitely check with U.S. Customs before you decide what to bring. Be sure you know the origin of the items, not just the type of products.

When you get here, declare everything that might be deemed a risk or dutiable. Find out the per-person non-dutiable value of gifts, and which items will be dutied regardless of the personal exemption (sorry, but I can't remember either of these as we almost never carry gifts or souvenirs in our luggage).

Side note -- once you declare the gifts, they may not like the sounds of what you've brought, so it may result in a detailed Customs inspection. It's not likely, but be ready to deal with delays on arrival, just in case. In my experience, the vast majority of U.S. Customs agents are friendly, helpful, and are not interested in making your life miserable. But they sure do get fed up with people who don't listen, don't follow directions, and behave uncooperatively. I've got a passport full of re-entry stamps, but I've only encountered one agent who really annoyed me. Even he seemed more like a grumpy old man than anything else.

Good luck!

p.s., regarding temperature fluctuations, the biggest issue is generally sub-freezing temps for extended periods, so consider whether you have anything that shouldn't be frozen (that's probably what caused @db's conditioner to separate); extreme heat is much less likely to be a problem.

I guess it would depend on what you're bringing... I have brought in from Spain - olive oil, wine, vinegar, saffron... can't remember if anything else. I placed it all in the suitcase because of liquids limitations, not for any other reason. It was all well packed in between towels and a huge ziplock bag I took with me for this exact purpose. I didn't want any breakerage or spillage to ruin my suitcase or clothes inside.

I've also brought Dulce de Leche from Uruguay, some other different type of dulce de leche (in bars) from Guatemala, and I bring avocados and mangos all the time from Miami and sun dried tomatoes and cheeses from NY to PR - these come with me on the plane... From PR to the US is a whole different story even though we have the same Dept of Agriculture... can't explain it.

Yeah, everything Loco said.

My mom brought back some interesting stuff from Korea, all dried and hermetically sealed. She didn't get any hassle, just a lot of questions about Korean food and what she was planning on making with all that dried red pepper. Of course my mom had to go into in-depth explanation of making kimchi and then offering to send some to the inspector. Lord knows how long she held up the line.

Don't forget for your return from the states to consider shipping anything heavy and/or potentially problematic (instead of packing it in luggage). Especially good for anything that might send your baggage to the overweight zone.

The US Postal Service actually offers very well-priced and reliable international shipping options. I recently shipped a 7 or 8 pound box of homemade cookies and other goodies to Bangkok for less than $50, and that was using the Express Mail option. All arrived in perfect condition on the day promised (in time for hubby's bday), and would have been double or treble the cost via FedEx or UPS.

Enjoy your visit to NYC (Central Park is easy, trust me), and check in with us when you get here. Be sure to let us know what you decide to bring and how it goes!

If the places you're buying from deal with tourists a lot, they'll probably have a good idea what you can take with and how it should be handled. And chances are, they'll probably also have ways to pack and ship the goods for you, so you don't have to bother. Of course, it's more expensive, but if you buy from a place like that once, you've made a connection for further shipments.

This reminds me of the story of somebody who bought some sort of huge sausage that couldn't be taken from there to here. Can't recall what the sausage was, but it was something special and fully edible as-is. So the person simply started cutting it up and eating it and sharing it with anyone who wanted some. It was either that, or hand it over to customs, or throw it away. Better to share.

Like everyone said, look it up. A friend of ours tried bringing back some sausages from a country that you don't need shots or a visa to visit, but they were confiscated and he was questioned. It was odd.

I work for an airlines and sometimes work in Customs and Immigration to assist passengers coming in, and I've seen all kinds of stuff that people try to bring through that are confiscated. Raw eggs, wormy apples, grape vine cuttings, dried meats.... and too often it's a little old lady who doesn't understand English or why her foods are all being taken away.

To be safe, I'd say no beef products or raw vegetables, but fish products are ok! I brought home 3 packs of barbecued eel and several cans of scallops just yesterday.
Also, if you are in doubt, declare it! You're a lot more likely to be fined for trying to hide something, than admitting you're carrying it. Although it still will be confiscated.

@Bella--
Fellow cigar enjoyer! My OH managed to get some cigars that originated there awhile back. He kinda just opens the box and smells them every once in awhile, so I've yet to try one. Soon!

Declare, declare, declare. False Customs reports are no joke. After that, follow the rules.

However, that said, in the past I have brought back (over the course of a few trips) cases of wine, cheese preserved in olive oil, jars of honey (although Customs had to make sure there was no honeycomb or bee parts in it - both are prohibited), olives cryopacked in oil, cured cryopacked meats, jarred duck confit and pate (the word "conservee" appeared to be the magic one on the label), olive oil, walnut oil, tapenade, tea, cookies, Jamaican Coca-Cola (made with real sugar!) and an assortment of cordials.

I highly recommend bringing neoprene bags (like the "Built" brand totes) to pack wine and other breakable liquids, as well as ziploc bags. I often put wine bottles into ziplocs and then pack into the neoprene totes. In fact, if I know that I will be bringing food home from anywhere (foreign or domestic), I usually pack an entire box of gallon ziplocs on the way out and load all clothing possible into the ziploc bags on the way back. Clothing that does not fit in a ziploc goes into a separate garment bag. This protects the clothes from spills and leaks and allows me to pack most food items into clear bags. Saves time if someone wants to inspect and keeps strangers' hands off of my unmentionables!

We recently came back from Paris into the US.
We were told that if the items were in vacuum packed sealed containers than it was fine to pack in our bags as well as carry on luggage.

We had a problem with the duck rillettes, only because I checked them, and when xrayed they looked like bombs because they had metal handles on the glass jars!!!!

We were asked down to security and had to open our luggage and go thru security 3 times at Orly. They were very kind and let us carry on the jars of duck! US customs has never said a word to me, and I always bring in pate and treats in my luggage.
Maybe I've been lucky!

No meat or meat derived products are allowed into the US from overseas. I bring back tea, chocolate, cookies and non-perishible food from Europe.

I for one, declare all food on the Customs form. For the persons that think they can get away without declaring foods, I have to say that I've seen dogs sniffing around luggage after passengers have collected it from the carousels so one can get caught.