As I'm sure you already know Rob, testing for safety after-the-fact is like closing the barn door after the cows all got out. The easier and safer approach is to just use the already tested and approved recipes and instructions. And there are plenty of them available for just about everything. That way safety is assured.

But yes there are a few tests you can perform at home although none of them are recommended due to the high incidence of error. pH meter and litmus tape can be used to test pH. Done correctly and with the knowledge that pH will rise during shelf storage they are better than just guessing at the pH. But the tape is easily contaminated and the meters are both expensive and require frequent recalibration.

Density of the foods, allowing for thorough heat penetration when processing, is the other concern and more difficult to measure although equipment is available.

Still one has to compute the needed processing time required even when the pH and density are known.

Lastly how can one test for the presence of pathogenic bacteria without culturing mediums, petri plates, pipettes, a sterile growth chamber, etc.? "(e.g., for testing for salmonella, botulism, excessive bacteria, etc.)" Unfortunately we can't do it at home. We can only function under the assumption that it is there and needs to be eliminated or neutralized.

Fermentation guidelines are pretty simple and straight-forward. Use a sufficient ratio of salt to weight of food and provide adequate ambient temps and all will work well. Canning acidic foods is also pretty straight forward. It is low-acid foods that pose the safety issues for the most part.

On the off chance that you aren't already familiar with NCHFP I strongly suggest exploring it and it's many publications and instructional links.

Hope this is of help.

Dave

Here is a link that might be useful: NCHFP

Thanks for the info. I definitely agree that safe food handling is paramount...prevention is best. I also know that there are a lot of variables, so one must always use common sense when eyeballing the results. I almost always toss things that are questionable...even though things aren't questionable very often. But, in the instances that they are, I was wondering if there were ways to test for microbes/etc. on my own. As per your reply, the answer is pretty much "no".

Just to dispel any notions of a mad scientist doing weird things and breaking all the rules...here are some concrete examples.

One example, my brother recently made some smoked summer sausage but somehow forgot to add the cure. So, he had ~50 lbs. of ready-to-eat sausage...provided that bad bugs hadn't taken hold (e.g., botulism). It would have been really great if I could have taken a sample and tested it myself...rather than just following the safety-first recommendation of "just throw it out".

Another example, I like to infuse oils with various raw garden produce (e.g., herbs and garlic). I know that this can also go bad...but I also know that longer room-temperature infusions taste better. So, it would be really great if I could do a home test to see if I had went too far.

Another example...fermenting sauerkraut and cucumbers. I know the recommended salt levels and fermentation times, but sometimes I'd like to adjust things a bit to suit my tastes (e.g., less salt, longer fermentation). My nose and eyes tell me if things have obviously went bad, but what about the other cases? Am I left just assuming that things aren't safe because I didn't follow the recommended guidelines? An accurate method of testing would enable me to try these sorts of alterations with confidence.

Another example...long low-temperature drying periods with lower-salt jerky.

Another example...aged homemade cheese that are covered with "hopefully the good types of mold".

Another example...homemade wine that "smells like" it's successfully transforming into vinegar.

Another example...occassionally testing our homegrown "they seem fine" chicken eggs for salmonella.

Another example...testing raw meat of our homegrown livestock or wild game to see if putting tartare on the table tonight is safe.

Etc...

In general, I'm just trying to see what sorts of after-the-fact tests I could add to my toolkit to help in my variety of food experiments. This isn't something I'd need to do all the time (or probably even often), but sometimes "just following the rules" and eyeballing/smelling the results isn't enough. I was just wondering what tests were possible in the home.

Thanks.

-Rob

Rob-
There will never be (well, never say never, but the risk is too high) home testing kits. Each form of bacteria requires a different protocol for testing. Let's say you have a specific test for salmonella and the test comes up negative. A lot of people would automatically assume "hey, there's NOTHING bad in this jar I canned". But you didn't run the additional test for Listeria or E. coli or whatever.

You might find neogen.com an interesting site if you're into that sort of thing. The company is geared toward testing kits and equipment for the commercial food industry, but they do have an extensive library of articles and a blog, some of which is pertinent and interesting from a consumer's standpoint as well.

P.S. There is no "test kit" for botulism. If I remember correctly, an ELISA test is required to identify the toxin. Which means you need a laboratory.

A bit of trivia: Do you know how botulism got its name? Botulus in Latin means sausage. "Sausage poisoning" was a common cause of death in the 18th and 19th centuries. During an outbreak, a scientist first isolated the bacteria from home-cured ham and named it "botulinum".

I hadn't seen your list of examples before I posted, so I can try to address some of your questions.

One example, my brother recently made some smoked summer sausage but somehow forgot to add the cure. So, he had ~50 lbs. of ready-to-eat sausage...provided that bad bugs hadn't taken hold (e.g., botulism). It would have been really great if I could have taken a sample and tested it myself...rather than just following the safety-first recommendation of "just throw it out".

Safety depends on how it was prepared and from what meat source it was made. If it was cold-smoked for a lengthy time in a closed smokehouse (low oxygen environment), then, yes, it could have the potential of being unsafe.

Hot smoked where the sausage reached an internal temperature of 165 degrees, then frozen - I'd eat it.

Same applies to your jerky. Is this recipe no cure plus lower salt?

Another example...homemade wine that "smells like" it's successfully transforming into vinegar.
Fruit wines are acidic enough to prevent any really bad things from growing. I wouldn't worry about that. If it gets a yucky mold, your nose and taste buds will tell you.

Another example...occassionally testing our homegrown "they seem fine" chicken eggs for salmonella.
As long as you cook your eggs and don't eat them raw, there's nothing to worry about. According to the CDC, one in 10,000 eggs is contaminated, and I'd bet most are from factory farms. Folks have been eating eggs from their own chickens for a long time, so I wouldn't worry about it. I eat raw eggs from a neighbor's chickens and never give it a second thought. I don't do that with grocery store eggs from who knows where...

Another example...testing raw meat of our homegrown livestock or wild game to see if putting tartare on the table tonight is safe.
Frankly, I trust home-grown/home-harvested meat a heck of a lot more than the stuff in the grocery store. Do you butcher your own or send it out to be processed? I butcher my own game, so I know how it's been handled. And, yes, I adore tartare from my home-harvested venison.

I don't do any fermenting (we don't eat enough to justify the space it would require), so I have no opinions on that.

As you can see, food safety encompassed a lot of variables - time, temperature, methods, etc. I do try to keep up with food safety topics and I also understand why the USDA/NCHFP/Ball etc. try to make procedures 102% safe.

Hope that helps a little.

Are there any DIY kits for home food testing (e.g., for testing for salmonella, botulism, excessive bacteria, etc.)? Or any recommended places to learn more?

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TO MY KNOWLEDGE and in my opinion:

As a home consumer there is no need to do food safety tests. Simply because it is not feasible.

But if you mean safe handling, cooking, canning there is a wealth of information out there to satisfy a home consumer.
How to handle, how to cook, how to .. etc.

But if your intention is about safety in home canning, again there are enough resources out there. Basically home canning revolves around TEMPERATURE,, ACIDITY and DURATION in processing time. Acidified foods (pH 4.5 and lower, the lower the better) can be safely canned by BWB method. You bring the item to near 200F+ and hold it for a given time .... seal it . No known harful bacteria can thrive, multiply and produce toxins in acidic environment. That is the beauty and simplicity of acidification principle.

In the case of non acidic foods , pressure canner is utilized to compensate for low acidity. Most know harmful bacteria are /will be destroyed at 240F+. and once the container is sealed there is no possibility of the food going bad , in the absence of harmful bacteria. chemical decomposition and aging is a different issue.
HARMFUL BACTERIA are the key words.

250°F is necessary to kill the spores produced by the Clostridium Botulinium, the most dangerous. 10 minutes is recommended even if just 4 are necessary in laboratory conditions. Of course if the ph is inferior to 4,6 pasteurization will suffice. ( Personally i refuse lemon juice in tomato conserves as for me it totally ruins the taste of the spicy sauces i often prepare ).

The spore itself cannot contaminate as it is strictly saprophyte therefore cannot colonize and invade a living organism. But it will produce botulinum toxin, responsible for botulism, rare but often deadly. The good news however is that this toxin will be destroyed at around 200°F therefore as long as a conserve is boiled for 10 minutes' (240°F) before eating no risk of botulism.

Agree but unfortunately many home canned foods are NOT boiled prior to consuming. Tomato conserves, which are often served cold, is one example. Salsas another, canned tomatoes fresh from the jar are often served cold, and many meats as well to name just a few. So using safe canning techniques from the beginning insures a safe product whether boiled after opening or not. If you don't care for lemon juice then citric acid is available for safety purposes.

Dave

I want to put up maple sap (not syrup). I have tried using a bit of citric acid and doing a BWB. So far the jars look clear, not cloudy. But how would i know if they have botulism? I can't seem to find any 'recipes'.

AFAIK there are no tested and approved recipes for canning maple sap. Everyone boils it into syrup. Nor any way to determine if it is safe. Instructions exist for syrup of course but it has been extensively boiled. But not the sap.

It isn't a high demand thing that would justify testing unless you wanted to pay a lab to do it. I can't even find a pH rating for it but I suspect it would be quite alkaline since it contains so much water. Since botulism spores exist all around us it is a do-at-your-own-risk canning exercise.

Dave

How about if i use a pressure cooker to can it? The sap is great and full of nutrients. I don't want maple syrup. Thank you for your responses.

Well a pressure canner would increase the safety odds. But we'd just be guessing at the amount of time needed. Even though it is a liquid it could be anywhere from 25 to 60 minutes and still no guarantees.

Dave

Thanks, Dave. Maybe i should just invest in a freezer

and once the container is sealed there is no possibility of the food going bad , in the absence of harmful bacteria.

Just a reminder that jars can seal even with bacteria in them, and that seals do fail from time to time. That is why every single home canned jar must be inspected prior to use, and why canning instructions from NCHFP must be followed closely.

If I use my canned maple sap to make applesauce or apple cider, which cooks for a couple of hours, would that be safe?

Boiling for 10 mins will destroy any toxins that may have developed in the jar. And those toxins are the real threat. Boiling doesn't kill the spores themselves, only 240 degrees+ can do that. But it will destroy any toxins. Just be careful with handling the jars, lids, spoon, etc. that might come in contact prior to the boiling.

Freezing would be the best option.

Dave

So, next year could i boil the syrup in a pressure cooker?

Dave, i have a pressure cooker now. Do you think i could put the sap in that and get it to 240 to kill the spores, too? How long would it have to stay at 240?

Thanks,

barb

No, it isn't quite that simple. It would have to be pressure canned, not pressure cooked. Pressure cooking and pressure canning are 2 totally different processes.

Cooking would kill the spores in it while cooking it. But they are in the air and on surfaces all around us so the simple process of pouring it into jars through a funnel mixes in air and re-exposes it to contamination plus it would leave air in the jars and that air could be contaminated.

When it is instead canned under pressure not only are the spores in the liquid killed but so are all the spores on the jars, lids, etc. all air is forced out of the jar and a vacuum is created that prevents any further contamination.

Dave

Sorry, Dave. I meant canned under pressure. Would that work? If so, how long would i process it? Thanks again.

barb

Well like I said above "But we'd just be guessing at the amount of time needed. Even though it is a liquid it could be anywhere from 25 to 60 minutes and still no guarantees."

I'd sure give it 30 min at least. But do keep in mind that is just a guesstimate so the risk is still yours to take. There has never been any testing done so the time used is your choice to make.

Dave

Im new to canning and food preservation. So much information..".to trust or not to trust." Yet even though I hear the bottom line is to trust only the approved testing, I find that I still have questions and have a hard time trusting my end product simply because of the possibility of human error. I read that there is a field test similar to a home pregnancy test that they use to detect botulinum in 20 minutes. Has this been made available to the public and if not, why? It's a great business plan if someone can come up with the science behind it. And Ill buy it. Home testing might also make it possible for others to continue testing since the government quit. But while we're waiting for that, I would like for someone to clarify some information. I know botulinum is the bacteria which produce the toxin (gases) that can hurt us. The bacteria die at a certain temp for a certain time. I have heard some people suggest to boil a home-canned product thoroughly after opening/before eating it to kill the bacteria, but this seems insufficient as the toxins would still be present. It is not the live bacteria that are toxic but the gases that they produce. Also the bacteria die when exposed to oxygen. Does boiling somehow neutralize toxins? Or is this just false information? Lastly, since bacteria produce gases, is it safe to conclude that jars tainted with bacteria would definitely have some outward visible signs of contamination? I know that other bacteria can infect food, but in my short studies I have been led to believe that botulinum is the hardest to kill. But do all bacteria produce gases and therefore provide some indication that food isn't safe?