I am traveling and would like to take frozen chestnuts on a trip about 11 hours long. They will thaw and not be cooked for a week so is it safe to re freeze them after the trip?
Hopefully someone with stronger background in Food Safe can chime in here, I'm just working from experience and traditional based knowledge. I would love to hear what modern science has to say on the topic.
Are you thawing raw chestnuts then cooking them then freezing them again? Or thawing from cooked, keeping out for a week then refreezing?
For the latter I would say most probably not safe. Protein and starches can grow some pretty nasty invisible beasties once they have been cooked, and freezing doesn't kill much of them, just slows down their growth. Having cooked chestnuts out of the freezer for a week, then refreeze would make me uncomfortable (and I eat miso paste that is two years past it's best before date).
Raw chestnuts on the other hand, I would personally feel comfortable thawing them, keeping them out for a week, then cooking them just (ie a couple of days) before refreezing.
I don't know what cooking resources you have on your trip, but perhaps something can be made from the excess of chestnuts?
I think what you are saying is taking raw, frozen chestnuts and then re-freezing when you arrive and then cooking a week later. It may affect the texture, but there isn't a safety issue to re-freezing them that I know of.
I just noticed they are cooked and frozen. Again, while the texture may be affected, I think safety wise, it's fine.
foodsafety.gov's general advice about vegetables is that if they've been briefly defrosted but kept cold, you can refreeze them safely, expecting possible texture changes. Once they've spent more than 6 hours above 40°F, they recommend tossing.
That sounds right to me. I know with a lot of starchy foods, like rice, pasta, chestnuts (which are considered a high starch food like potatos http://ucfoodsafety.ucdavis.edu/files/44384.pdf), there are some pretty nasty things that wake up when the food has been cooked and are not killed by reheating/freezing. In Traditional cultures, these foods can be stored at room temperature for long periods of time (like years) safely, however it usually requires addition of enzymes (like are found in fermented foods). Using rice as an example, traditional cultures would use koji mold for long term (more than a month, upto 10 years) fermenting/storage of cooked rice, or umeboshi (pickled plum) for short term (24 hours) room temp storage. See this BBC article for an introduction on high-starch food safety issues: http://www.bbc.com/news/magazine-25154046
In my experience on the farm, chestnuts are the fastest spoiling and most sensitive of all nuts. They go moldy or rancid if you look at them wrong, especially once out of their spiky cloak (chestnuts grow in clusters within a spiniferous sphere). But then again, that's home handled nuts. I forgot to ask the OP if these were commercially prepared chestnuts.
Commercially prepared chestnuts are often treated with gasses (which may or may not need to be labeled, depending on where you are in the world, but most places not as the gas is considered 'used up' in the processing). These gasses can arrest many bacteria and molds that would otherwise have a field day on cooked chestnuts.
Then again, most cooked chestnut packages I've seen say 'eat within 24 hours after opening/thawing, or store in fridge up to 3 days' (paraphrased).
In conclusion, there are food safety issues here which are good to be aware of. But how serious these issues are? I'm not qualified to say.
I have re-frozen uncooked, peeled chestnuts before that my family had picked up fresh from the farm and peeled it ourselves. It's not as fresh and there are organoleptic differences (as expected) such as being a little drier than before, but in terms of safety uncooked ones should be okay. I'm not too sure about the cooked ones though...
I want to thank each responder to my question about chestnuts. I have the already peeled and cooked chestnuts frozen for a trip across the country by plane. If they go in a suitcase that is checked and put in the luggage compartment perhaps they will remain frozen. I am nervous about them going rancid or getting people Ill though so I guess I will search for fresh ones when I land.
Why not put them in a small cooler inside your checked luggage. My husband used to do that to haul frozen foods from WI to NJ and they always frozen. I don't think I would do this if it was summer or you were traveling to or from somewhere really warm, but if you are going from one relatively cold place to another during the winter you should be fine.