It's basically the fluctuation in pressure. And perhaps over-packing. That leads to siphoning (venting of liquid from jars).

This is a learning curve, understanding your stove. Electric ranges are most challenging. It's very important to maintain a consistent pressure to avoid the kinds of problems you describe. Over-packing just exacerbates the problem.

Carol

Also, the apple type needs to remain firm when exposed to the heat of the canner. As ReadingLady has mentioned, the canner needs to be watched carefully and controlling the heat is very important. Most of the time its best to have all the jars filled with very hot contents when they go in the canner. In another thread, I mentioned Macoun apples as being one type that seems to hold up very well to the heat of cooking. Please don't expect these apple slices to be as firm as commercially made store bought, but at least you have made them your way.

I would be inclined to lay most of the blame in this case on over packing. The size of slices vs. puree or liquid would usually call for more headspace in most recipes - 1" minimum - OR for a better ratio of slices to liquid - less slices and more liquid.

Then the pressure changes only compounded the problems. We have all been there and done that ;) so rack it up to another learning experience.

Dave

PS: I find it really helps to have/use the weights rather then the gauge. They get your attention much faster than the gauge does. What brand of PC are you using and are weights available for it?

It may be better to can the apple slices in a BWB instead. Adding enough sugar, and/or acid will help to keep them from any possible contamination. When a canning recipe calls for water, I usually don't add much. Instead, for things like jellies, I use fruit juices, and for pickles, I use all vinegar, with very little, to none, of water. If your concerned about the more headspace, you can always do these in quart jars instead.

Truly a nightmare experience. If I were you, I'd go back to the tried and true BWB as well, but I have to tell you that I pressure my apple slices and have never (thankfully) had such a bad time. The worst that happens is that the apples shrink, leaving me wit a not-so-pretty jar.

So I made a few mistakes: 1) I tried to cram too many into the jars; 2) I allowed the pressure to fluctuate too much; 3) Headspace?

1) I'll get the temp. fluctuation part better next time now that I know this new canning element heats hotter than the old element.
2.How do I know how many slices are "too many?" My only reference point is with canning pears, and I always end up with jars that seem to have less fruit in them than they could have...
3. Headspace...not sure what I should have done differently - the recipe said 1/2 inch, so after I put in the slices, I added syrup so it (and the slices) came up to the 1/2 inch (bottom of the threads).

Thanks again for the help.

.How do I know how many slices are "too many?"

You want the individual slices to be lightly surrounded with liquid or for it to at least be able to get in between them a bit.

The goal isn't so much to get as much fruit as possible packed into each jar but to get a safe balance of both slices and liquid. It is the liquid that conducts the heat of the processing and if the fruit is packed TOO tightly you end up with cold spots in the center of the jar where the temp doesn't get as hot as needed. So better too little slices and too much liquid than the other way around. ;)

So as I asked above - what type of canner and are weights available for it?

As too headspace - you can always increase it up to an inch max safely, you just can't reduce it from what is called for and when it says 1/2" it means a liberal 1/2", not a "maybe" 1/2" ;).

Dave

Also, you did hot pack these, right? So some syrup was going into the jar at the same time as the slices.

Store bought apple slices are about 3/16 to 1/4 inch thick each. The core is cut out, but I have seen skins left on. The store bought are a deep red color too, which is probably a coloring added as well as spices.

Sorry to forget the canner. It's a Presto - I can fit 7 quarts on one layer, and apparently, I can stack pints on top - though I've never done it that way. I don't know if weights are available - would I use those instead of the dial gauge, or would I replace the single weight with the measuring one??

As I stated earlier, I was following a recipe from the NCHFP. It says to use approximately 19 # of apples for 7 quarts. After packing the slices fairly loosely, I had, at a minimum, 1/3 of the slices remaining. I thought I was packing too loosely, so I pressed down and added more! The recipe also recommends 1 pint of fluid for every 5 # of apples. That wasn't even close to enough liquid for all those apples, esp. if they were packed loosely. To be honest, I am feeling a bit deceived by the recipe. Maybe someone could help me understand? For the record, again, I'm an experienced and trained cook, and although new to pressure canning, I do know how to follow instructions and recipes, and how to render 'slice,' 'small dice,' 'chop,' 'mince,' etc., including '1/2 inch headspace.' I'm not displaying attitude, just frustration at a recipe that seems grossly out of proportion.

Again, thanks for all your help. I have all these really beautiful apples and I'd love to can slices, but if I don't know what I did wrong last time, I'll be more likely to sauce 'em!

Here is a link that might be useful: Here's the recipe link:

I don't think anyone here thinks you're showing "attitude" in expressing a natural frustration.

One of the issues in canning is variations in yield which can occur for a number of reasons. I routinely find I need to prepare extra syrup/brine for certain recipes and take meticulous notes so I am prepared the next season.

Some recipes are right on target as to yield but others aren't. Just a question - the 19 pounds is apples before preparation not the yield sans skins, cores, etc. Is that how you measured? It would be somewhat less of prepped apple slices.

The Presto can be fitted with a three-piece 5-10-15 pound weight and then you can use the gauge as a backup. That's highly recommended.

Carol

I definitely agree with Carol - your frustration is totally understood. ;) As I said, we have all been there and are sympathetic. Unfortunately so much of canning knowledge is only acquired only over time and lots and lots of practice rather than explained in recipes.

Some of the problem will hopefully be eliminated soon as more and more recipes are being converted to accurate measurements rather than "pounds" of product or "use 2 large".

In the mean time, when working with a recipe that is vague, it helps to post here up front as many of us can give you conversion measurements and tips such as the always make at least 1/2 again or more syrup/liquid than called for. ;)

And please believe that pressure canning is one of those "takes practice" things in life regardless of how long one might have been doing other types of canning. ;) Wife and I have a good 80 years at it between us and we still learn new things every year.

The 3 weight set that is available for the Presto canner is a definite must have - easier and safer. Costs about $12+ and is available several places. You'll find many discussions here about the advantages of using the weights vs. the gauge as well as links to where to buy.

The reason I asked about hot pack is while that recipe - we have used it several times - allows for raw pack, it also discourages doing it. It says "Raw packs make poor quality products." It also says "syrup per 5 pounds of sliced apples." So you have to re-weigh the slices before making the syrup. Makes a big difference but 1 pint of syrup for 5 pounds of slices still isn't going to be near enough and you are right - it would be really nice if the recipe pointed that out. ;)

That recipe also doesn't tell you how to slice the apples - vertically or horizontally. That too makes a big difference in the packing and the amount of syrup needed.

The headspace thing is optional within reason and the only reason I brought it up is because we have learned over the years that when it comes to pressure canning more headspace is often better because it allows for the bit of fluctuations in pressure that you sometimes can't control.

Sure the recipe calls for 1/2" but that doesn't mean that you MUST use 1/2". Fruit floats, horizontal fruit slices float more than vertical slices, slices float more in light syrup than in heavy syrup, etc. SO horizontal slices in light or medium syrup will pose less problems if you use 3/4 to 1" of headspace. Just a tip - it's your choice. ;)

So cut yourself some slack, relax and hang in there. Do the rest of your apples. You are doing great! ;)

Dave

Apple size, its density, and overall texture can give variable results when they are canned. To add a syrup, it would be great to simply boil down apple cider to an almost gel point. That way, the sweetness is concentrated and also gives the syrup some 'body'. Not everyone can successfully can in a pressure canner each and every time. Suggest that you try different apple types to see which will hold up to heat well. Macoun is a late apple and is great for cooking and baking. Apples like Granny Smiths, Macs, and Cortlands tend to get very soft very quickly. Another issue is how fresh the apples are. Even if stored for a couple of weeks, they tend to lose moisture and start to get mealy and dry. When I decided to plant apple trees here, I figured in several factors. Disease resistants, then the ability to withstand cooking and baking heat. I chose two types and both have shown their worth when it came to making apple pie filling.
The Presto site below lists several pressere canner models and also offer the weights, as well as other parts and gaskets if they are needed.

Here is a link that might be useful: Presto link

Thanks again everyone.

SO, when I try sliced apples again, now that both the pressure canner and I have cooled off ;-), i will try the following:
1. I will still use vertical slices, because I use a very light syrup ( just 50% water and 50% apple juice);
2. I will add the slices to the boiling syrup in small batches, making sure they come to a boil before loading the jars. I'm thinking about 2 jars' worth at a time...
3. I'll pack the slices quite loosely into the jars. I'll probably stop the slices at the 'shoulder' of the jar, and then fill with syrup to the headspace level.
4. I'll use a one inch headspace.

How does that sound?

I'm also checking the local hardware store for the weights...
Thanks for your patience. Pressure canning does seem to have a steep learning curve that is disturbingly well-related to 'luck,' given that it's a science... I made some Annie's Salsa last night, and was able to keep the pressure to exactly 11 pounds the entire processing time. How disappointing, after following the proper cooldown procedure, to find that they had siphoned liquid - leaving too much headspace in the jars. Since they sealed very well, and my garage storage area is quite cool, I'll just put them to the front. But still, frustration continues!

It may be that the cool down is done too quickly if there is still siphoning going on. I would think that horizontal slices of apple would make a better fit in the jars. As to a syrup, I hate adding water to something like this as its just not as flavorful, plus water dilutes the acid level. Don't forget the ascorbic acid to prevent them from turning brown! If you don't have a manual for your pressure canner, suggest that you read up on the whole process by going to the Presto site and download or print out the manual for there models (typically 23 quart one). At least it can cover the basics and could tell you something to help correct the loss of the liquids inside the jars. For me, the tightness of rings screwed on is firm, but not overly wrenched on, and not too loose that you could unscrew them with just 2-3 fingers and thumb.
Keep it up, your get to that 'magic spot' soon..

Heat off, pressure to zero, wait an additional 10 mins. then crack the lid, wait a min. and remove it keeping it turned away from you. Check the jars, is the liquid still bubbling in the jars? You'll see the small air bubbles rising in the liquid.

If so, let them sit a bit longer. It usually only takes a couple of mins for it to stop. Then carefully remove the jars.

Link below is to the 8 causes of siphoning chart at NCHFP. Check it out for more tips and causes. Good luck and be patient. You've done what? 3 or 4 PC things so far? How many practice runs with just jars of water? That's the way to learn the quirks without wasting produce. Just like driving - you didn't just get in a car and take off down the street right? ;)

And don't expect perfection till you have oh, say 20-30 batches under your belt. ;)

Dave

PS: I'm with Ken on the syrup - too watery.

Well, as I said, I followed the proper cool-down procedures (I always have.)
I use the correct headspace exactly (and always have).
I have had trouble with getting the pressure to stay on target and not increase by a few pounds, but I think I've got it now.
I've been using ascorbic acid for a few years - that is an improvement over lemon juice, IMHO.

As you wrote earlier, Dave, there are no notes in the recipe re: horizontal vs. vertical slices, or how closely to pack the apples in the jar. (My engineer husband thinks I'm in the kitchen practicing voodoo as I hunch over the computer searching for clarity, and hover over the pressure canner, adjusting the heat every couple of minutes...)

Finally, it does drive me a bit crazy when, on many threads here I read that the headspace in the recipe must be followed exactly, but later find that: "Sure the recipe calls for 1/2" but that doesn't mean that you MUST use 1/2". Hmmmmm. Very difficult to learn about how that might work by just filling up jars with water and heating them up in the canner for practice...

As for the juice mixed with water -- I don't eat much sugar, so commercially prepared juices are very sweet to me, and I water them down. The recipe states "Place drained slices in large saucepan and add 1 pint water or very light, light, or medium syrup," so I shouldn't have to worry about acidity, correct?

But again, thanks very much for all the suggestions, even if I still don't know how tight to pack the slices, or which direction to slice them, or how much headspace to use... ;-) I don't give up, ever, so I'll try again later this week, if anybody wants to give me a definite answer on any of those topics (definite as in "here's what we do in our house with apple slices") Cheers!

Finally, it does drive me a bit crazy when, on many threads here I read that the headspace in the recipe must be followed exactly, but later find that: "Sure the recipe calls for 1/2" but that doesn't mean that you MUST use 1/2". Hmmmmm.

On the headspace issue - you are talking about 2 very different things. ;) Yes, you must follow the recipe when it comes to MINIMUM headspace left. If it says 1/2" then yes there must be a minimum of 1/2" and no LESS. But it is safe and allowed to increase head space slightly if needed. If it says 1/2" then you can safely INCREASE it. Not to 2 or 3" obviously but to 3/4-1" instead of the 1/2".

We have found this to be very helpful over the years when dealing with very thick products such as salsa and apple pie filling. And you will find many approved recipes for salsa which stipulate 1" headspace so with that particular thing there is an approved range.

Very difficult to learn about how that might work by just filling up jars with water and heating them up in the canner for practice...

It is a very beneficial practice as many will tell you and is a standard practice recommended in many canning classes. Not only does it let you learn control of the heat and pressure stability but it teaches you about siphoning causes and how to prevent it.

A few runs with jars of water filled to the 1/2" mark but that come out with more headspace when finished shows that you either aren't stabilizing pressure as well as you think, aren't screwing the bands on enough, or have an imperfect seal before processing. Granted you can't learn about the removing all the air from the jar before capping cause or the starch foods cause, etc. but it does help.

I forgot to post the link above. Sorry.

Most of the rest just comes with practice over time as there are just many variables - in this case variety of apples, syrup density, your stove, how strong your twist on the bands, etc. - to control or predict them all.

So, for what it is worth, we use Granny Smith and Sungold apples because that is what our trees are, we slice vertically because we find it is easier to fill the jars, we use a 1 c measuring cup to dip out and to fill with slices and syrup (we use the standard fruit medium syrup recipe) at the same time to the shoulder of the jar then remove all the air bubbles and top off the jar with syrup only to the bottom thread, check for air bubbles again, wipe the tops, screw on the lids and bands to finger-tight, and process. We bring the heat up slowly till the PC has vented well for 10 minutes then put on the 10# weight. Once it begins to rock we slowly reduce the heat in micro-amounts until it is just doing its minimum rocking motion (our gauge reds slightly over 10# at that point), and begin the timing. When the timmer goes off, we turn off the heat and let the canner sit till zero.

We wait an additional 10 mins. then crack the lid, wait a min. or so and remove it keeping it turned away. We check the jars to see if they are still bubbling. If so we let them sit until they stop and then remove them carefully. We have minimal if any siphoning problems but then wife and I have been doing this for more years than many have been alive. ;)

Dave

Here is a link that might be useful: NCHFP Causes of siphoning

Thank DAve, I really appreciate the detail, and I know it takes some time on your part to document it online. You do a couple of things differentyl than I did - I put all the apples in, then added syrup, while you add them both at the same time. I keep the canner on at a near-boil as I load the jars, and keep it high until it has vented for 10 minutes, then turn it down quickly - if I do it incrementally, the pressure goes up too high. I make incremental changes after that point and can now hold it where I want to hold it. Sooo, I'll load the slices differently, and I'll try bringing up the heat more slowly. Thanks again.

Lemon juice and ascorbic acid are NOT interchangable. Lemon juice (bottled) is added to bring acidity up in the canned product. Ascorbic acid is not going to bring up acidity, and is used ONLY for preventing oxidation and darkening of the canned product. Electric stoves can go crazy when it comes to heat regulation. Keep in mind its metal thats heating up, not a big flame under a pot. Remove the flame and it cools down quite fast. Shut off the electricty and metal burner still holds onto a lot of heat. Start at a low setting for electric and wait at least a minute or two before moving it up a little more in heat. Try to anticipate its higher heat setting when it starts to reach the ideal setting. Some people don't know that there are several settings for electric burners, and crank them up to high to get things cooking, which will usually burn some things. The ONLY way to get pressure to remain at a proper amount is with the weights. If you are using a dial guage and depend only on that for the pressure readings, it could be off by several pounds. Say you want 10 pounds, and the gauge is not accurate (after many uses), it could be showing 10 pounds when its actually beyond 15, or worse, below 10.Thats the reason that dial gauges are always a big concern. Todays canners have both types of pressure reading devices, but the weights do ALL the controlling of pressure, where a dial with a pointer is used only to see if its above zero. A few have had gauges calibrated, but its not going to hold up to accuracy. Calibration is ONLY a conversion chart where a dial reading would equal an actual pressure. Some are not linear and once they go above 10 pounds, can be off by 2-5 more pounds, even if the pointer is just above the 10 pound mark. In my opinion, calibration of a very cheap dial gauge on a pressure canner is a useless option, as these cheap gauges have no interal part that can be adjusted to be more accurate. For the headspace, a 1/2 inch is usually minimum, and you can go up to an inch in some cases. Any spices added?

Using jars filled with just water as a 'dry run' can help. The water inside the jars would be colored with a little food coloring. If the water in the PC becomes that same color afer a process is completed, its obvious that the jars leaked or siphoned some out. Also, the level inside the jars drops. Snug tightening is necessary and any pressure build up will still push its way out of capped jars, provided they are not wrenched in very tight. My dad used really wrench down, and even he couldn't open some after they were done! Imagine giving some canned goods away and not even being able to open the jar...?

Here, I can't usually have sugar at all. Instead, I will use a frozen juice concentrate, or Splenda. If its too sweet at the beginning, I will use an acid blend to bring up acidity as well as food safety. Apple rings in a water based liquid is low acid (due to the water dilution), so presure canning is necessary. Adding an acid or a higher acid juice, will increase its safety and at some point could be water bath canned, provided its high enough on is own.

Adding the apples and syrup at the same time keeps air bubbles from getting trapped in between the slices. So less air to remove before putting on the lids and less left trapped in the jars.

Water temp prior to inserting the jars into the canner shouldn't ever be more than 180 degrees top.

Also, the waiting 10 mins before removing the lid is a relatively new guidelines so I thought you might not be aware of it. ;)

Dave

Thanks for your concerns. I meant that I prefer ascorbic acid over lemon juice as a way to stop/slow browning, not as a substitution for acidity. The recipe from NCHFP I have been referring to re: apple slices says that using water is acceptable for slices - even with a BWB. If there is new guidance out there, I'd love to see it somewhere!

And Dave, I've been lurking around on the site reading copious amounts in preparation for learning to pressure can (thanks goodness for this site!!), so I was aware of the new guideline to wait 10 minutes - although I didn't know that early in September when I started this year's canning! However, I hadn't really paid all that much attention to the 180 degrees - I just make sure it's not quite boiling when I drop in the jars. Could that be a factor in siphoning, and why?
Thanks!

I had a similar expereince with Water bath. I found I need to boil my apples for a bit before I put them in the jar. When I do this, they will froth up a bit, then settle down. I don't boil them long, but I do make sure to bring the syrup (a very light syrup) to boil after I add the apples. I do a bit at a time so the syrup returns to a boil quickly. I didn't want my slices to turn to mush.

I did one batch were I only heated up the apples and didn't actually bring them to a boil where I got the froth. When I canned them, they must have "frothed up" in the jars and almost all of the syrup got pushed out of the jar and into the water. They all sealed up fine, but the apples sort of got expanded to fill the jar. When I released the lid, it made that sucking sound and the apples compressed to fill about half the jar and turned really mushy - really looked strange.

I don't know how well they would have kept, I used them up right away. Those that I boiled slightly before putting in the jar turned out like they should have. I did about 50 pints of apples this way, and only the one batch that I did differently turned out strange.

My apples are from the tree that came with the house - have no idea what type they are.

Cathy