Wondering if I have to boil my homemade jars of salsa to seal them if they sealed on their own. (Yes I sterilized them before hand) The salsa went in hot and once the lid was on, about 5 minutes later there was the telltale pop!

IF this is safe, how long does something like homemade salsa and homemade sauces keep for in sealed jars?

Thanks! ~Andrea

5 Answers 5


Yes, you should fully process your salsa, even if you got the "hot jelly" seal just from hot packing.

The reason for this is that part of the processing is to ensure that the entire contents of the jar, all the way through, is at a high enough temperature for a long enough time to be safe as a shelf-stable product. This may or may not already be true from the initial cooking down, but in these matters, you absolutely positively want to be sure.


All the books I have read on canning and preserving say that in order to safely process a non,or low acid fruit or veg ,you must pressure can it. They even go so far as to say that Tomatoes ,which have usually been the one "veg" you can hot -water bath, should be pressure canned ,because todays' market tomatoes are low acid. The best book I have found on storing food is called " Putting Food By" the book explains how and why to preserve food to get the best results, (I just checked, it's available at Amazon,an as a Kindle) but I borrowed my copy at the library. Another source of Good info is the Bernardin website, take care.

  • 3
    This is true - though I don't think it's because today's tomatoes are different, but rather because tomatoes are very close to the boundary between low-acid and high-acid for canning. In the past, people were a bit less cautious, and sometimes there is sufficient acid anyway, but in general, it's not safe.
    – Cascabel
    Commented Jan 8, 2014 at 15:56
  • 2
    I just add ascorbic acid powder (vitamin C) to my tomato-based preserves. It raises the acidity using something out bodies actually use. Then I can hot-water process with impunity. :)
    – Shalryn
    Commented Sep 22, 2016 at 16:46

I realize this is an older question, but I am not sure any of the response have addressed this sufficiently. There is a clear difference between hot water canning for high acid products and pressure canning for low acid products. In a hot water canning situation (typically high acid products) it is salt (sometimes sugar...the idea is a reduction of water activity) and pH that are the control for pathogens, including botulism. The only way to know for certain which process is safe is to measure pH. If the pH is 4.6 or lower, you are safe to go with hot water canning. Otherwise you must you pressure canning. One can either do a search for the product online or, if absolute certainty is desired, pH can be measured with test strips that can be easily acquired in most places.

The challenge in this case is (a) tomatoes vary in acidy depending on variety, and (b) we don't know what else is in the salsa. I would measure the pH to be certain. The answer to the question is that if this salsa is a high acid product, and appropriate for hot water canning, then the hot water canning process must be followed in full (meaning, yes you need to boil). While the acidity/salt controls the botulism risk, there are other potential pathogens that boiling will control for.


Depending on what went into your can there is a risk of botulism... The ingredients that go into salsa include this risk factor (onions are a source of botulism).

Botulism grows in oxygen free, non-acidic environments (IE a sealed jar of salsa) if the spores are not killed, eating your salsa might kill you. As less then 2.8 ng of botox (toxin produced by botulism bacteria) is lethal. And lethal in a very short period of time.

The temperature that ensures that the spores are dead and your canned food will remain safe is 115 C. For 2 Which is not reachable for a food containing water unless you use a pressure cooker.. (as water boils at 100C at sea level air pressure).

This is why you use a preasure cooker for canning non-accidic food.

It is possible it won't be a problem... But it is better to be safe then sorry.

See National Center For Food Preservation for a guide.


Yes, you have to boil the jars after the lids go on.


There is dust in the air. Each dust particle has at least 4 to 5 bacteria living on it, or there are mold spores living on the dust particle.

If a single grain of dust enters your mason jars while the lid is off, and then you put the lid on, then the jars must be heated until the inside of the jar is above 212° Fahrenheit (100° Centigrade).

Sterilizing the jars of food before filling the jars with food serves no useful purpose.

There will always be at least one grain of dust which lands in the food before the lid is put on.

Given that microorganisms replicate and spread, your sterile glass jar will become non-sterile after a dust particle lands on it.

Before the lid is applied to the top of the jar, the jar is guaranteed to have live micro-organisms inside of the jar.

The purpose of the lid is to prevent any more additional micro-organisms from penetrating the inner confines of the your jar of food.

After sealing the jar shut, to keep out new-commers, you must immerse the seal jar of contaminated food inside of a pot of boiling water for at least 45 minutes in order for heat from the hot water to migrate through the glass and into the inner contents of the jar.

Even more time is needed for jars larger than a quart, such as one-gallon jars.

The heat will kill the micro-organisms, not the water itself.

So... the lid keeps new germs out, but the germs from a single speck of dust which drifted down into the jar while the lid was off must still be killed.

Kill the germs inside the jar by immersing the entire jar in boiling water after the lid goes on.

Anything inside of the jar, except the bacteria from a hot springs or deep sea lava vent, will be sterile after the jar is sealed and immersed in boiling water for a long time.

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