Does my raw fish have to be "sushi grade" to make ceviche?
My friends having a hard time finding sushi grade fish at our local grocery stores. She should be fine using just "regular" fish, right? I don't know...I've never made ceviche.
Different fish and shellfish absorb citrus and "cook" at different rates. Tuna for ceviche is out of bounds as citrus destroys it in 30 minutes. What sort of fish/ shellfish are you contemplating? Generally one does the citrus bath with just the fish, folding them in according to a careful time line for "ceviche mixto " (the best, IMO) , and then combine with fresh pico de gallo just before it is served. Sushi grade is meaningless for this dish, just freshness.
I think she (my ceviche making friend) ended up with halibut or sea bass (?). (Honestly, I wasn't paying much attention when she was telling me as a strangely behaving racoon materialized on my deck and freaked me out just a bit).
She's made it several times before (usually with mahi-mahi) and it's absolutely delicious, but she recently read somewhere that you should use "sushi-grade" fish and was concerned. I told her we'd never been sick before...so why worry? But then she reminded me we had recently been to the borderlands of Mexico the day of a gun battle and didn't get shot...which didn't mean we would be so lucky next time.
"Sushi grade" and "sashimi grade" are marketing terms, pure and simple. They have no legal or commonly-accepted practical definition. They mean whatever the person selling you the fish thinks they mean. So you can let your friend know that the person who told her to use "sushi-grade" fish doesn't know what s/he is talking about.
You have literally been through a Mexican gun battle and have a magical rabid racoon materializing at will on your deck and you are worried about the trivial difference between sushi grade and regular fish. Oh just make sure fish is fresh and definitely smell it before you buy it. As others said sushi grade means absolutely nothing.
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For parasite safety reasons, restaurants are required by law to freeze raw-served fish to -31F/-35C for 15 hrs or -4F/-20C for 7 days, although allegedly (and unsurprisingly) some cheat according to some other Chowhound posts (and also some were closed and/or fined when found to be in violation.)
According to other posts on here, there's no hard and consistent rule (although I sure as hell wish there were) to naming conventions. You'd best check with your fishmonger.
IF sushi and/or sashimi grade meant that your particular fish seller source meant it was frozen to proper temperatures to sterilize all parasites and that it was otherwise maintained with best hygene practices (surfaces not exposed to any bacteria laden contact), I'd say go for it (you can try cutting the top layers off if u're unsure of surface quality.) Or buy your own ULT freezer to render parasites non-viable --they aren't always killed, just rendered sterile in some cases. I hacked a sterling cooler apart in order to build my own cryofreezer --I'm on a lookout for a surplus cryogenic dewar / vacuum insulated canister to home blast freeze in a solution of calcium chloride, fun fun.
*cringe* every time I hear people say lime juices "cook" the raw seafood into a sterile-safe-for-consumption state, a piece of me dies X_X --chemically denaturing does not equal cooking. LoL. < http://www.bigfishtackle.com/fishing_... >  NOTE: the temperature and safety instruction by the author in that link are woefully inadequate, 40 F or C would do nothing.
Funny note on parasites: Farmed salmon (when fed processed/ground-up fish) have minimal/no anasakis parasites (but way more PCB's --yum I <3 mutagens =P .) I've seen parasites randomly in fish at restaurants, and I eat them (after I uncurl them for fun.) =) =D
And for anyone who says nobody gets parasites, a friend of mine just had juicy tape worms removed the size of his pinky . His buddies always joked that he must have had parasites b'c he had the appetite of a stoned sumo wrester (really weird food craving at all hours.) I think I'm only one of the few people crazy enough to wonder (and want to find out) what the worms would taste like cooked and spiced up [well not HIS worms of course... that'd be a little weird...hrm... on the other hand....
Just because people been doing something for a long time or in a popular fashion _DOES NOT GUARANTEE SAFETY_ --just ask smokers or betel nut chewers.
Kids in South America get trichinosis at an much higher rate.  And Japan has a much higher rate of anisakiasis --when I heard a workmate talk about eating raw fish caught right off the boat I sure hope it was Tuna. French and Brazillian's have much higher infection rate of toxoplasmodium gondii due to eating raw mammals. Crazy cat ladies get it from their cats (can really mess up pregnant womens' fetuses) --and I wouldn't be surprised if the stray I just adopted has toxo too. We're just surrounded by fascinating things. =D
P.S., I've had an obession with parisitology since second grade; a fascination with public health with regards to toxicology since sixth grade; and a fascination with food and food gadgets since forever.
Hrm... maybe tell ur friend if she gets worms, she can gain the eat-unlimited-desserts-and-gain-no-weight superpower. Atypical helminthic therapy... =) .
 I had a link to a research article discussing the proper pH and temperature in cerviche necessary to assure a targetted margin of safety from botulism --I forget the exact concentration.
 I don't know if he had diphyllobothriasis (fish tapeworm infection) or if he had Taenia solium worms (pork), or T. saginata (beef worms) inside him instead.
 Trichinosis has funny freeze time rules too, but freezing only work son domestic pork. Wildboar/bear/fox have natural antifreeze and different family of trichinella --more amusing tidbits: free range pork has higher rate of trichinella infection and/or toxoplasma gondii ('cuz they get exposed to more critters.) *shrug* I don't eat raw pork anyway. Ice doesn't form intracellularly until negative -15C in some cases. The U.S. Army Engineer Research and Development Center has an informative publication on this subject < http://www.crrel.usace.army.mil/libra... >
< typo fixed, links updated >
Note: I meant to say there are areas in South America with much greater infection of neurocysticerosis not trichinosis. Neurocysticerosis from T. solium due to undercooked pork and poor adherence of hygenic handwashing procedures (those restroom signs are there for a reason!.) Trichinosis is more in N. America & Europe due to undercooked game meat, naive trust in (ineffective-for-game-meat) freezing, or food preparation/preservation procedures not adhering to FDA/USDA specified guidelines. Top restaurants create, have, and follow a HACCP (Hazard Analysis and Critical Control Point) plan --which may be superceded by ISO 22000-- to assure patron safety. The plans are refined and updated as well, like with the case of a high temperature resistant pathogen such as norovirus that struck The Fat Duck, (was ranked #1 in the world and still holds a high ranking) which now only uses oysters that have gone through an extra step to make sure they're norovirus free and additionally they verified that norovirus is immune to standard alcohol hand sanitizers.
You simply can't assume that "fresh", "natural", or "organic" _automatically_ mean healthier or safer. I love how lower rated "B" grade oysters can be safer than "A" grade oysters raised in "pristine" waters because "B" grade oysters are required to go through a depuration step. HACCP analysis is a effective way to quantify and isolate risk to the degree that is prudent.
< http://www.saferfoodscores.co.uk/News... >
If you like eating dog or just hugging them: there's Echinococcus gramdosus, a dog tapeworm that you can get also from petting infected dogs (hoo frick'n ray.) -- also a desc. about how the dwarf mouse tapeworm infects 1-2% of pop. of Southern States. 1/3 of all rats sold in pet stores (study based in Conneticut) carry H. nana.
< http://www.time.com/time/magazine/art... >
< http://en.wikipedia.org/wiki/Hymenole... >
I get a laugh out of the insidious cute disarming butt "scooting" that dogs infected with Dipylidium caninum (a flea-tapeworm) will do sometimes (not that scooting necessarily guarantees infection.) "Oh what a cute puppy --> OMG why do I have all these worms hitchhiking inside me >_<!" I still let them lick my face... I just wash after.
< http://www.peteducation.com/article.c... >
My OCD friend is strangely horrified yet entertained by all this as well...
re: Sam Salmon
Seriously, don't feed the troll ;)
Here's the short-short version --I thought the -4F for 1 week was enough info-- stick to the "safe" specific tuna or farmed salmon listed in < SashimiCevicheBroch.pdf > ( Salt Lake Valley Health Department) or freeze to -4F or less for one week (get a thermometer, try colder by a few degrees to take in account of thermometer error) and you'll generally be A O K. When working on a yearly project feeding hundreds of people day after day, we get random kitchen inspections. If anything is out of place from anyone (and we have random newbie chefs we have to monitor) we get instantly shut down, so yes, I'm kind of a slave master about safety. My motto was always (both there and when cooking for guests or for parties): "Nobody gets sick on my watch." =)
The original post is a query about food safety. The baseline diligence necessary for parasites is very clear, well tested, and documented. Hey, I'm just pointing out your seatbelt, it's up to you to put it on.
Thought provoking notes about the Tuna vs. other fish and 5min recommendation. I keep in mind to only use Tuna if I'll be chowing down on it fast and passing that info to my friend who loves to make ceviche for me. =D.
[ For those that are making shrimp ceviche ]]
My fav. (albeit old) article on the subject (b'c I liked its thoroughness in regards to proper acidity, rate of acid penetration, temperatures, and safety margins) < http://aem.asm.org/cgi/reprint/25/5/8... > [2
Short summary: pH 3.7 sauce @ 40:60 meat/sauce ratio, with immediate chilling to 10C for 24hrs.  pH botulinum growth cutoff point was determined to be 4.86 pH crab and 5.03pH shrimp [note: 5.06pH shrimp would result in botulism toxin creation.]) It lists procedures and safety levels for higher temps as well.
That process on fish no thicker than 10mm + freezing any fish not on the parasite-free list at -4F/-20C for a week, would leave me relatively comfortable serving it to anyone with regards to botulism and anasakiasis safety.
 It's funny how just a 0.03 pH difference was enough to allow toxin generation. You want a much lower value to give a safe margin of error.
 cite: Peter Lerke. "Evaluation of Potential Risk of Botulism from Seafood Cocktails". Applied_Microbiology (Vol. 25, No. 5) May 1973. *And I don't know why Chowhound.com keeps messing up my formatting; it insists on taking my closing bracket to the following line... >_<
 Not taking into account mercury exposure limits for particular problem prone fish that I'd have reservations giving to anyone pregnant or super young esp. in large quantities of course. And I'd prefer chilling to marinade at a much colder temperature (i.e., closer to 0C rather than 10C) to minimize growth of any other pathogens.
What about tuberculosis? I was filleting a fresh caught bluefish a few years ago (not intended for sashimi or ceviche) when I saw this disgusting growth...looked like caviar, but in the wrong place...growing in the kidney and against the spine. I took a photo before tossing the fish and sent it off to the DEC. I was told it was a granuloma, caused by tuberculosis bacteria, and that it was a good thing that I decided not to eat it....
This is from memory, I'll try to put in the reference articles later.
Short-short versions: no pre-treatment for raw. Cooking to pasturization temps listed in Douglas Baldwin's table should render it reasonably safe provided there's not gross infection. Cooking to baseline 62.8C @ 30Min+ is better, but it's not gonna taste too good. Fishmongers are supposed to throw out gnarly fish so buy good quality fish from them.
*Note: this is assuming Lysteria is more temp. tolerant than Mycobacterium Tuberculosis/Marium/piscium/et al. strains. pref. not from a tank that has ones with eaten fins and rotting fuzzy spots. Fish consuming dead infected fish are super fast contagion route. The stuff is a royal pain to clean out and generally there's no cure for the fish rather than severe cleanup (there are some antibiotics that work for aquarium owners.)
As far as I know there's no pretreatment for raw fish to prevent it, but rates are low. Like 168 cases / yr US(?) --anisakiasis is even lower at 10/yr now due to better safety awareness. The cases are more often due to swimming in unclorinated bodies of water, acquarium cleaning, fishmongers, anglers, and oyster shuckers (hand protection is recommended in all cases.)
There's lots of types of Mycobacterium in fish, but the most often reported one is M. marinum of which there are two strains. One fast (fish) killing one that is human infectious and one slow acting one that isn't listed explicitely so. They attack extremeties due to favoring colder growth temps. Mainly risky for the immunocompromised (transplant, AIDS, blood disorders) but healthy people _can_ get it and the antibiotic treatment is a biatch (like 6 months or somethings and often is misdiagnosed due to rarity and similarity to other illnesses. But I couldn't find info confirming whether or not you can get it from consumption as you can get Milk Tuberculosis (which used to have 10x rate of pasteurized vs. non pasturized area infection in London ages back before we effectively minimized infected cows and consistent pasturization.)
Both Tuberculosis and Listeria monocytogenes had the same listed pasteurization temp listed at 62.8C for 30min (that was extrapolated to be like 4 hrs at 55C (for thin items, 9 hrs for higher widths.) But in tests 4 major main types of foodborn versions were killed in milk at the LTLT (low temp + long time) pasturization procedure, although other Mycobacteria managed to survive (also proper quick chill procedures need to be followed unless food is served immediately.)
There's a sous vide iphone app. that lists different types of fish and holding temps. Although according to cookingissues.com the most tastey temps are lower than pasturization temp., so you'll have to take your chances at less than that (the chances aren't too bad to be honest, buy good quality fish as recommended by others here [I suggest freezing non-Tuna, but it's true slow freezing will quite possibly hurt quality vs flash frozen or totally fresh.)
The pasturization procedures listed are only for modest contamination rates (like in milk or otherwise healthy fish.) The huge # of Mycobacterium camped on in the macrophages in the granulomas are not necessarily made safe with default procedures. FDA and/or USDA recommends not serving any fish with obvious illness, if you cook it to extra high temps or an extended period of time, it'd likely be safe but it'd taste like proverbial cardboard.
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