Q: Several months after canning strawberry jam, I looked at the jars and the top layer of the jam was brown and smelled and tasted bad. Any idea what I may have done? It was so disappointing!
I do this every year and the brown stuff has never happened before. I did not waterbath them (never have). I did the upside-down method due to the acid in the berries.
— Question asked by special
Marisa: I am so sorry to hear that your jam spoiled; that's so disappointing! While turning jars upside down can produce a seal (because the heat of the product coming in contact with the lid causes the sealing compound to soften and then seal as the jars cool), the seal tends to be weaker than one produced by a short boiling water process (you should never be able to remove the lid from a home canned jar with your bare fingers. If you can, your seal is too weak).
You have to be very precise when using this method of canning — the jars and jam both have to be as hot as you can get them (and the jars must be perfectly sterile) otherwise you run the risk of a failed seal. Additionally, the inversion method of sealing doesn't always force out all the oxygen in the headspace. Mold spores live in the air and so if oxygen remains in the headspace of the jar, chances are that the mold will then grow in your jars.
In order to give yourself increased peace of mind, I'd recommend that you consider a brief boiling water bath for your next batch of jam. That's the only way to be certain that you've killed any mold or bacteria remaining in the jars and that you get the optimum seal.
Marisa McClellan, our guest expert this week, is answering your questions on canning and preserving. Marisa writes Food In Jars, a blog devoted to canning, preserving, and other food in jars. She also teaches canning workshops.
Previous Question for Marisa:
• Is It Safe to Can Meat Sauces?
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If the stuff looked and smelled bad why did they taste it?
view Comicgeek's profile
Always, always waterbath. It's the only way to truly ensure safe, edible goodies for the future. No canner worth his or her salt would ever recommend the upsidedown method.
I waterbath half-pints in my rice cooker of all things. If you don't have a pot big enough, consider smaller waterbath batches. Just reuse the water over and over!
view bfootnovellista's profile
Sounds like you already answered your own question Marisa - the inverted jar method is not considered safe - for exactly the reason you have experienced!
I'd say it is time to get back to basics and read a good book on canning. Here is a good free one from the USDA.
Much as I hate to say it, canning is not something we should learn from previous generations. Science has come a long way since Granny was doing this.
view Bushidoka's profile
If the jars in the picture are your jam, then you must have reused the lids. That particular style of lid is hard to get a good seal on and difficult to sterilize for reuse. Always, always use a new lid for canning jam and sterilize it in a water bath for at least 15min. I always use the hot fill, upside down method for jam and never have problems. Use only sterile Mason canning jars, new lids and tight fitting rings.
view lona's profile
the acids and sugars in strawberries and other fruits can vary for the same fruits even grown on the same patch. sweetness and acidity of fruits can be affected by the amount of moisture and the air temperature while the plant is growing. for canning, even the inverted jar method (which is really not safe at all), you need to have a more consistent acid/sugar ratio. one way you can do this is by adding lemon juice or powdered citric acid to your jam batch or lots of sugar to thwart bacteria.
view pedalpowered's profile
When mom made her jams and jellies every year, she sealed the jars with wax. a nice layer that we loved to pop out when we opened it for the first time.
view mikeinbrooklyn's profile
My mom and I used to do the same, mikeinbrooklyn, but really, I find the waterbath method much simpler. It's safer and I don't have to clean the wax that inevitably escaped off every nearby surface!
view tariqata's profile
What's the purpose of not waterbathing preserves? I get it for pickles and other things where additional (or any) cooking changes texture, but jellies and jams are already cooked down. Why take the risk?
view Married ...with Dinner's profile
Marisa and helpful commenters: Thanks so much for your kind answers, I appreciate it!
Snarky commenters: The pic isn't mine, I sterilized new lids. Also, waterbathing ALL (without exceptions for high-acid items) preserves is relatively new. Until a few years ago, store-bought pectin packs - yes, mainstream brands - suggested the upsidedown method. That only changed about 5-ish years ago. I was going off that recommendation.
view special's profile