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Martin, Engineer
Category: General
Satisfied Customers: 4954
Experience:  i'm 41 and i never stopped studying and experimenting
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Can I pressure can Roasted Vegetables in Glass canning jars

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Can I pressure can Roasted Vegetables in Glass canning jars without adding additional water or brine? I just roasted an oven full of red potatoes at 400 degrees and I would love to stuff them into several court size canning jars with a tablespoon or so of olive oil and some sea salt and crushed pepper for later use.
Is that possible or do I need to fill the jars with added water (making yucky soup)??
Hello. I just saw your question, by now it's probably too late :) but i see no problem doing that. Minimizing the air quantity in the jar to a certain level would be good that said, so pack them up to only let the top air gap needed for the vacuum.

Potatoes is not something i would personally put in Jar as i can keep mine for month in a fresh location in their natural state, but i do apples and they are similar to potatoes (they are not called pommes de terres in French for nothing, both are pretty much only Starch). Some apple pieces eventually float on the syrup i use, 1.5 inch over the liquid line and still conserve fine (i used to flip them over before but now i don't even bother).

Just be sure to heat sterilize you jar well.
Customer: replied 7 years ago.

I want to accept your answer because you seem like a cool guy but it seems to miss my main question. I am asking about (Pressure canning only) not water bath canning and my main worry is the added risk (if any) of Botulism growing in the jars if I don't add water to the fill line but I still process the jars at the reccomended pressures and temperature for low acid foods such as potatoes.

Apples are a very high acid fruit and can be canned without worry as long as they are cleaned but potatoes and other low acid vegetables are dangerous if processed incorrectly.

I hope this makes the question more clear, when I wrote it it was aimed at a culinary expert so it was perhaps a little vague for an engineer.


The spore causing botulism is anaerobic meaning it would develop even without air. I must be honest and say i don't know why it's usually recommended to remove air bubble. It is not because of botulism as you still keep an air gap at the top of the jar anyway. I think it's more related to getting a good vacuum and perhaps to the way the liquid will conduct the heat better to the food (as air will tend to isolate).

So if lot of air is present, i think the pressure/temperature should be increased and also the time the food is at that required pressure. Then if the cover is well sealed, it's should stay fine.

Note that i never made potatoes like that so this is on the speculative side.
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Customer: replied 7 years ago.

Hey Man thank you for your time and trouble..

I accept your answer.

Happy engineering.

Best reguards