my courgettes are still cropping so I decided to preserve some in oil. They were cut in half (as they were only small) oven roasted, put into a parfait jar, covered with hot oil and sealed while still hot.
That was about 2 weeks ago.
The jar is leaking oil and I opened it to not only have a look but try to stem the flow. There was alot of air pressure under that lid. Is this normal or do I just chuck the lot out?
Stumped and grateful for some input on the current situation and some pointers for next time (cos they're still cropping!)... ???
If there's pressure after potting, that means the food is fermenting and should be discarded :'( but on the bright side it's a fail-safe signal - I remember a few jars 'blowing' every year at home :o
On BBC's Return to Italy a lovely old Italian lady was preserving courgettes in oil. The first stage was to 'cure' them for a couple of minutes in boiling vinegar, then lay out on a cloth to dry, add garlic and herbs, then cover with cold olive oil:
http://www.bbc.co.uk/food/recipes/database/preservedcourgettes_82377.shtml
The Italian method/recipe would raise the acidity of the food and sterilise the cut surfaces, which would probably prevent fermentation under oil next time, but only short term - it doesn't have a very long shelf life, probably because of the high water content of the vegetable.
Glad you asked this question bennetsleg cos I meant to look up the link :D good luck with the next batch :)
Do be careful when preserving things, definitely wouldn't use them. You will note that the recipe that supersprout shows contains vinegar - there is a general rule that if good vinegar is used in the proportion of 1/3 of the weight of the solid matter, it will increase the acidity to a level high enough to preserve.