Canning "uncannable" foods

[digigirl]

Okay, I've got a bug and now I HAVE to know the answer to this question, or I'm gonna go bloomin' insane (or maybe I already have.....)!

Recently I decided that I wanted to get into canning. While researching this, I find that there are certain things that are "Not Recommended" for canning by the USDA guidelines. Namely, things like pumpkin butter, lemon curd, chocolate sauce, caramel sauce, etc. I understand why, that's not the question. I understand that commercial canners have "additives and processes that home canners do not have." Okay.

So then I got to thinking, what about all those small "gourmet" companies I see out there selling dessert sauces and lemon curds and pumpkin butters and stuff? So, I go look up a few of them online and look at their ingredient lists. No additives on the list that I can find that have anything to do with preservatives.

So then I start searching everywhere - what is the magic process used for putting these things into jars and making them shelf-safe? Is it super high heat, or what? I've been searching all afternoon.

Can't find a single thing anywhere that actually explains the process. Nothing for sale, no processors' websites hawking their services for this purpose. Nothing. I've exhausted all my ideas. Obviously, there's a way - but what is it?

So, here I am. I figure somebody here MUST know, right? How does it happen? What is the secret that makes uncannable items cannable for commercial processors, but not for us?

Please help me before I die of curiosity!

Valerie

[adegiulio]

I'm with you. After putting up some sour cherry jam last weekend, I have also caught the canning bug. Now that the garden is finally starting to produce after a cool wet spring, I'm going to have more vegetables than I know what to do with.

So, I too would like to know some secrets...

[Badiane]

I believe that you can in fact 'can' those sorts of things. Commercial purveyors would use some kind of pressure canning process, which, if you had a pressure canner at home, you could do without a problem.

I personally would not try to can meats, although my mother does it all the time and has never had an issue in 58 years of doing so.

I don't do lemon curd because I worry about the eggs, but chocolate sauce and caramel sauce, fruit sauces etc all work really well with the same method I use for jams.

I wash the jars and then heat them in the oven at 275 for at least 10 minutes - usually however long it takes me to make whatever it is I am making. I boil some water and drop the lids in as well, sterilize the funnel and all that. I fill the hot jars with the hot whatever, put the lid on and wait for them to pop. End of process.

Pumpkin butter is the same to me as apple butter, and that works, using the same process, so what the heck. I also use that same process for cooked applesauce with zero sugar and I have no issues.

I prefer to freeze my veggies, but canning those at home would require hot water processing that is very simple to do. Same with peaches and whatnot - you just have to follow the process and it works just fine.

Now back to my pickled beets that seem to be taking me all day to get in the jars.

[sazji]

I believe the issue with things like pumpkin butter is similar to that with non-acid vegetables -- you have to be *very* careful to do it right or you can get botulism going. In this sense pumpkin butter is very different from apple butter; apples have acid that preclude the growth of botulism while pumpkin does not.

[chromedome]

It is necessary to use a pressure canner to safely preserve items like meats, seafood, and non-acidic vegetables (squash, beans, peas, etc). For a good overview of how to can the most common household foods safely, you may want to consult the USDA canning guide. It's also available in downloadable .pdf format from many sites. There are also numerous books available from sources like the Rodale Press (publishers of Organic Gardening magazine) which offer more detail and a wider range of foods.

I don't know what prices run for those down in the States, but if you have the bug in a serious way it's not excessive. It can also save you a ton of freezer space.

[digigirl]

I've actually already lookd at the USDA canning guide online, as well as homecanning.com and multiple other sources.

The issue here isn't whether home canners can can (what a sentence, huh?) these items - according to the USDA, we can't. The issue is, okay, I understand I'm not supposed to - I just want to know what the pros have, that we don't!

Even with a pressure canner, pumpkin butter and chocolate sauces (and other stuff) are a no-no for home canning, according to the government. Yet, these things are for sale commercially - even by very small, home-kitchen type businesses, so obviously there is a way to make them safe.

THAT'S what I'm looking for. What are they using? Some kind of additive / preservative? A more expensive piece of equipment that home canners wouldn't buy?

Anybody know? Even if it's nothing I would be able to do, I still want to know. The curiosity is killing me!

[Darcie B]

Wow, I didn't know there were so many foods that the USDA does not recommend for canning. I can understand the stuff w/eggs, but not canning caramel sauce? Sounds strange.

While searching this question (as I would like to can such things as well) I found this website with recommendations from a state extension service for canning lemon curd. It was even using a waterbath, not a pressure canner. However, they only recommended keeping it for 3-4 months. They recommend freezing for longer storage (up to 1 year). Anyway, here it is: Canning Lemon Curd. Hope this helps.

[jsolomon]

For some of those, you need some interesting stabilizers otherwise your product may break on you, just like a sauce will break or separate.

Others, you may have problems with acids, etc.

Best of luck!

[digigirl]

I found this website with recommendations from a state extension service for canning lemon curd. It was even using a waterbath, not a pressure canner. However, they only recommended keeping it for 3-4 months. They recommend freezing for longer storage (up to 1 year). Anyway, here it is: Canning Lemon Curd. Hope this helps.

←

I have a lemon curd recipe in this book too, and with the acid content of lemon curd, I'm pretty comfortable canning that. Thank goodness, 'cause that one is one I really do want to do.

Sure wish I could find something telling me how to do chocolate / caramel sauces, though. They say to put it in the freezer instead, but that seems like a much less convenient gift, to me.

Makes me wonder if some of those small home-type businesses who are selling pumpkin butters and chocolate sauces are just canning them anyway, without doing anything special, even though the USDA says not to. Hmm.... things to think about!

[Gekkani]

My sister-in-law and I have been canning together every summer for a few years now, and she on her own for several before that. We get together and make pickles (my grandma's recipe tastes great and is easy, there's no brining or cooking the pickles) all kinds of jams and jellies and canned fruits. We even made lemon curd last year. We also made a lemon jelly that included an infusion of lemon verbena, I was so upset when I realized I hadn't written that recipe down and couldn't find it again, that was a terrific jelly! I finally found it 2 weeks ago online after months of searching cookbooks and websites

Sis has a pressure canner and makes great use of it. Leftovers from a batch of green chili? Can it! She goes out of her way to make soups and such in extra large batches just so she can can the leftovers to have on hand. The pressure canner will come with a book to tell you exactly how to can the low acid/sugar items. Not one person in the years of her canning, or our grandmas for that matter, were sickened by home canned foods.

The USDA guidelines will naturally be more strict than they necessarily need to be, in part to protect themselves from lawsuits ("Well *they* said it would be ok"). I'm not saying to discount them by any means, but I do think they go above and beyond a bit. IMO they are trying to protect the public at large from harming themselves because, frankly, people are morons, lol. If they say an item would be ok as long as, and only if, you use the proper pressure someone will inevitably make it with only the inversion method and poison their whole family... With careful attention to procedure and proper equipment, I see no reason why you can't can those items yourself, we do it.

As for commercial methods, far as I know it's a matter of the high heat and pressure, 'cause there isn't any difference in the ingredient lists of their gourmet caramel sauce and my homemade one...

[bethanyhoffman]

I'm bumping up this thread because i have the same questions as the OP. I got a canning bug a few years ago and after success with jams and syrups, was really looking forward to canning my own chocolate and caramel sauces for gifts to friends and family, but could not find instructions anywhere for doing so-- and more than a few dire warnings. I've found a few recipes for cannable chocolate sauces that were made with mostly sugar and are really not the same. But very small companies sell their own sauces at local specialty shops, not to mention bigger companies, so there must be a way. Anyone know the story of how to make caramel or chocolate sauce safe for canning (even if it can't be done at home)?

[nickrey]

Classifying food for canning involves measuring its pH. Food is classified either as low-acid (pH>5.0), medium-acid (pH 4.5–5.0), acid (pH 4.5–3.7), or high-acid (pH<3.7).

For canning, one of the main concerns is Clostridium botulinum, which does not grow at pH less than 4.5. Taking the opposite view, you need to be concerned about Clostridium botulinum growing at pH levels above 4.5.

For acid or high acid foods, you can use an open water canner (immersing the cans, bringing the water to boiling and leaving the temperature at this level for the recommended time).

The lower acid foods you are talking about require a higher temperature than can be achieved boiling water. The only way to do this at home is to use a pressure process. This same process is used in autoclaves for sterilisation of medical equipment.

You will thus need a pressure canner, or pressure cooker (which does the same thing). The times taken are determined by the nature of the food itself and the temperature used. Details of this are too complicated to put into this reply. Suffice it to say that safety requirements for low acidic foods require longer periods of exposure to high temperatures.

Bear in mind that heating the foodstuff to these high temperatures will cook it at high heat, hence you could end up with a bacteria free but taste and texture spoiled product.

In summary, if you want to do low acid foods, you need to be able to heat to temperatures higher than the temperature of boiling water. At home this can only be achieved in a pressure canner/pressure cooker. If the food will be spoiled for eating if heated to high temperatures, you can't really do it and be safe.

[deltadoc]

Just so everyone gets this completely straight: You cannot use a pressure cooker to do what a pressure canner can do.

Got this straight from Presto in Wisconsin. Largest manufacturers of pressure cookers, pressure canners and pressure cookers/canners.

We've been canning all sorts of things for over 35 years. Only thing to watch out for is loss of vacuum usually due to a small chip on the sealing surface. You must check carefully for these, because sometimes the process of opening a canned canning jar can chip the sealing edge.

Also, if the color changes or it smells bad, throw it out. On the other hand botulism leaves no smell or taste. That makes it a sneaky bugger to watch out for.

doc

[jackal10]

Its a little more complex than just heat.

You want to ensure the food and the jar are sterile, sealed and do not contain spore forming bacteria (like Clostridium- botulism) that are hard to destroy with just heat without spoiling the food.

At home you heat the jar in a canner for long and hot enough to achieve the desired pastaurisation. The problem is for tightly packed food you have to heat the jar long enough so the centre achieves the desired temperature, and this can overcook the food.

Commercally this can be done outside the jar - flash pastaurised, for example, and the food then handled and packed aseptically. Hard to do at home, or without the specialist machinery.

[nickrey]

Just so everyone gets this completely straight:  You cannot use a pressure cooker to do what a pressure canner can do. 

Got this straight from Presto in Wisconsin.  Largest manufacturers of pressure cookers, pressure canners and pressure cookers/canners.

We've been canning all sorts of things for over 35 years.  Only thing to watch out for is loss of vacuum usually due to a small chip on the sealing surface.  You must check carefully for these, because sometimes the process of opening a canned canning jar can chip the sealing edge.

Also, if the color changes or it smells bad, throw it out.  On the other hand botulism leaves no smell or taste.  That makes it a sneaky bugger to watch out for.

doc

←

Presto was reiterating the USDA recommendation not to use pressure cookers for canning. This is based on differences in size and thermal properties of the cookers/canners, particularly in terms of times for heat up and cool down, which are included in the processing times given. Because of these differences, the timings for a pressure canner cannot be used on a pressure cooker while maintaining the safety margin.

I do use a pressure cooker for canning stocks (I have more shelf space for jars than freezer space so canning is necessary if I am to use home-made stocks with convenience). These are left under pressure for times that give a conservative safety margin. The timings are calculated from food processing tables rather than from manufacturer's booklets.

In my earlier reply I stated that the details of timings are too complicated to put into a reply here. Safety in food processing is not an art, it is a science. Basically you need to know the Fo values appropriate to the food, which is the total integrated lethal effect (lethal to bacteria, not to humans) required to deal with the bacteria typically found in that type of food. Also involved is consideration of heat applied, thermal conductivity of the material, and the size of the container. The maths is typically something that should not be tried at home and requires access to scientifically derived lethality tables.

Sorry if I didn't make this clear earlier. This is a safety issue we are talking about here. If you intend canning food regularly, follow delta doc's recommendation and get yourself the proper instrument, which is a pressure canner. Then follow their directions to the letter.

[deltadoc]

Just so everyone gets this completely This is a safety issue we are talking about here. If you intend canning food regularly, follow delta doc's recommendation and get yourself the proper instrument, which is a pressure canner. Then follow their directions to the letter.

←

Hoy Hoy, Nickrey!

[andiesenji]

I will add my caution to the above posts. Use a pressure canner - they range in size from modest to huge - I have both a smallish one 21 qt., and the huge - 41 qt., (All-American) which holds 19 quarts or 32 pint jars. (I use it on the burner that came with my turkey fryer, which is low enough that I can lift the rack easily from the vessel)

Even the smaller ones are awkward to use on a regular stovetop unless one is fairly tall.

You may see "steam canners" advertised and these are okay for high-acid foods, jams, and etc., but not for meats, fish, beans or any other low-acid foods.

[Carrie TZ]

Are there any more answers to this topic since 2006? I saw the opening question posted by digigirl the other day when I was doing a google search looking for the same answer! And still, I've found nothing! I've read all the posts about acidity etc. but, I'm curious what commercial processors do to can things like lemon curd and salad dressing and other such foods. I have a small green grocer in Dar es Salaam, Tanzania and I want to start offering items such as these to my customers. I've found the automatic lid-sealing machines sold from China, but, I still don't "get" what is done to make the ingredients safe. Just buying the commercial bottles and lids and a machine won't help me with the process. Most processed items here of high quality are imported! Can anyone help?

Thanks

[Emily_R]

While I don't know this for sure, I think a good guess for what manufacturers have would be machines that operate at much higher pressure than home pressure canners. Higher pressure would equal hotter internal temperatures... Hotter temperatures are likely to either be able to penetrate into thick stuff (like pumpkin puree), or allow for shorter canning times to kill the botulism spores -- thus reducing the degradation of the product that might come with long cookin.

[Emily_R]

Ok, and here's a book on Amazon that appears to get into the process of commercial canning...

http://www.amazon.com/Essentials-Thermal-Processing-Gary-Tucker/dp/1405190582

(It looks like much of the book may be scanned on Google Books, so also check there)

[Carrie TZ]

Thanks Emily for the quick response. The machine that puts the lids on the bottles is just a conveyor belt with a large piece that comes down and attaches the lid. So, the product isn't in a heated space from the looks of it. I've asked the company in China and they don't care to respond... they just want to sell their machines. Also, what about things like salad dressing? wouldn't the heat destroy the product?

[Carrie TZ]

I'll check the book out... and Amazon ships to Tanzania! Yippy

[Carrie TZ]

I've looked at just the cover of the book you mentioned, but this looks like its for HUGE commercial processing. I want to make small batches for my tiny shop, of 100-200 bottle runs. If I could use a pressure canner to process the products, I would, but I don't know if this works for the commercial bottles with metel lids. Any ideas on how I might do this affordably?

[Emily_R]

Sorry Carrie -- no idea on small scale implementation. My posts were mostly just responding to the initial question of 'what is it they can do at the factory that we can't do at home.'

To that initial question -- apparently the show How Its Made on the discovery channel has covered a range of products that seem like they'd be of interest... Season 10 episode 1 looks at commercial salad dressing, and Season 10 episode 3 looks at mayonnaise...

[pastrygirl]

Carrie, I think jackal has the answer, commercial products are pasteurized/sterilized before going into the can, and the process leaves no room for contamination. Good luck with your business.

You want to ensure the food and the jar are sterile, sealed and do not contain spore forming bacteria (like Clostridium- botulism) that are hard to destroy with just heat without spoiling the food.

At home you heat the jar in a canner for long and hot enough to achieve the desired pastaurisation. The problem is for tightly packed food you have to heat the jar long enough so the centre achieves the desired temperature, and this can overcook the food.

Commercally this can be done outside the jar - flash pastaurised, for example, and the food then handled and packed aseptically. Hard to do at home, or without the specialist machinery.