No water bath jam
I made my first batches of strawberry jam in the fall. I still have some jars left. The person who showed me what to do told me that filling the sterilized jars, sealing them, and turning them upside down until they were cool would be enough to create a good seal. So I made them that way.
Since then, I haven't heard of anyone else doing this and now I'm afraid that they aren't safe to eat. I've already been through several jars just fine but I'm worried about the others. Is it possible to boil the jars now without opening up the jars, reboiling the jam, and putting them into newly sterilized jars? I made them with about half the sugar since the strawberries were so sweet and the juice of about half to a full lemon per batch.
Are they fine? Should I store them in the fridge? Please help!
For future reference, if I use less sugar, what would the boiling time be for the filled jars?
Way back when, that was how I learned to make jam - though I never reduced the sugar.
Well, except when I'd use the Pomona's Pectin to make lower-sugar jams.
Anyway. . . I, my entire family, former in-laws, school's worth of teachers, Sunday school teachers, pastors, hostesses and any other lucky recipients have all survived. (I'm pretty sure.) I'd think, as long as the jars have remained sealed and there's no sign of deterioration, they're probably fine.
That said, there are a lot of things that used to be "okay" that, now, we've learned better ways.
I always thought after you got a seal on the jars and heard the ping, you could tighten the screw ring, turn them upside down for maybe ten minutes to redistribute the chunks of fruit so they didn't all rise to the top. Then turn right side up again to let cool and set up.
Don't tighten the screw ring down until the jar and seal has cooled completely. If you tighten the ring or flip the jar upside down while the seal is still warm you could disturb and compromise it.
To help prevent floating fruit, macerate the fruit overnight with 1 cup of the sugar from the total amount used in the recipe. It will draw liquid from the fruit (reducing the amount of air in the fruit) and then use the fruit, liquid and all, in your recipe. Air that is in the fruit itself (and raw packed tomatoes), not the bubbles that you release while packing the jars, is what causes the fruit to float. I haven't tried this for pepper jelly but it solved the floating problem for summer fruit jams and whole fruit preserves for me.
Another way to distribute the fruit or peppers through the jam or jelly, is to skim it, then wait 10-15 minutes, then very gently stir before ladling into jars. If the fruit is still floating after the water bath, wait until the jar is just warm to touch, pick it up and swirl it in every direction EXCEPT upside down. You may have to do this several times.
I haven't heard of turning them upside down, but I make jam by sterilizing the jars, filling them while hot, and making sure that the lids seal properly
More worrying is the fact that you used half the sugar called for by the recipe. That means that you didn't actually make jam - jam has to be 67% sugar by weight or more, or it won't keep properly, as the sugar acts as a preservative. 1/2 the sugar plus sealing upside down plus not water bath processing would be too much of a risk for me.
All the things dave_c said are correct.
Check the seals. If you can remove the lids easily with just your fingers or the lids are flat or convex instead of concave, the seal has gone bad. If you see bubbles or it's fizzy in anyway it's fermenting. Throw it out. If you see mold, throw it out. Some people think you can just scrape the mold off and it will be fine but recent studies show that the mold can extend unseen down into the jam and contaminate the rest of it. Molds producing aphlotoxins are indistinguishable to the eye from molds producing mycotoxins and while the jury is still out it's suspected that aphlotoxins may be cancer causing. If you have any doubts about the jam just throw it out. Your peace of mind and your stomach are more valuable than a couple of jars of jam. You have no worries where botulism is concerned. The high acid environment of a jam is not conducive for botulism spores to make toxin.
If you feel comfortable with the jam, since you made it in the fall, your best bet is to transfer it to freezer containers and freeze what you have left. Freezing it will alter the texture but a good stir after thawing should take care of that. In any case it's too long after having made the jam to reprocess the jars in a water bath. Next season learn how to can using a water bath. It's really very easy and your county cooperative extension probably offers free beginner classes.
That method is not currently recommended by the USDA.
The concern is that turning the jars upside down may contaminate the seal which leads to poor sealing. Another recommendation is to hot water can the jars to ensure the product is sterilized.
On the upside, strawberries are acidic and the addition of lemon juice helps. The acidity discourages botulism. Also, the strawberries were cooked.
Is your jam safe? Most likely yes. People still make jam this way and have not gotten sick.
If they did get sick, they don't live to tell about it. lol! (Just kidding)
However, I would hot water can the jam, if I were to make jam. Personally, I would just make freezer jam. The fruit isn't cooked so freezer jam has a "fresh fruit" taste.
For reference, I like the National Center for Home Food Preservation (USDA).
Another good site is from the jar and lid making company (now owned by Jarden