How long would this keep in a jar in the fridge? I made some a week ago and it was still good today. I didn't add any cheese, just blended together garlic, basil, salt, pine nuts, and olive oil. It still looked and tasted fine today but I was just a little worried about botulism. Anybody? Thanks!
Homemade Pesto Sauce
- Thread starter Chopstix
- Start date
The friendliest place on the web for anyone that enjoys cooking.
If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
ChefScotty
Cook
Ten days, a year if you freeze some of it when you make it. Perfect time of year to make and freeze some.
It freezes well, it keeps a couple weeks if well oiled in the fridge...also push the plastic wrap right down over it to form an air barrier.
cara
Master Chef
the bacteria that produces botulism, Clostridium botulinum, is an anaerob bacterium... it can't survive in jar in a fridge, because there is too much Oxygen around...
if it would be canned and sealed air-tighten, there might be a chance, but you would see it, as the Clostridium produces a gas... there would be pressure on the can...
if it would be canned and sealed air-tighten, there might be a chance, but you would see it, as the Clostridium produces a gas... there would be pressure on the can...
cara said:
That's not quite correct and it does bring up an interesting point. It is recommended that things like homemade garlic oil or herb oils not be stored for longer than a week because of the possibility of botulism. The anaerobic conditions are formed/provided in the oil. You may see the results of bacterial growth (in the case of Cl.botulinum, from spore activation) in an improperly processed can by a bulge in the can, but it is the toxin of botulism that is the poison and it is tasteless and odorless. It is inactivated by heat.
So, I guess we are just lucky with the pesto--and truth be told, I have used garlic and herbed oils in the past.
cara
Master Chef
okay, there are anaerobic conditions in the oil, you are right...
and the toxin is indeed tasteless and odorless, but there should be some gas bubbles to be seen, as the metabolism produces gas...
I must admit, I can't remember any botulism- intoxications from Pesto here in G....
and the toxin is indeed tasteless and odorless, but there should be some gas bubbles to be seen, as the metabolism produces gas...
I must admit, I can't remember any botulism- intoxications from Pesto here in G....
jennyema
Chef Extraordinaire
From Colorado State University ...
"A second important factor affecting the growth and toxin production of Clostridium botulinum is temperature. Proteolytic types grow between temperatures of 55 and 122 degrees F, with most rapid growth occurring at 95 degrees F. Nonproteolytic types grow between 38 and 113 degrees F, with an optimum for growth and toxin production at about 86 degrees F. For these types, refrigeration above 38 degrees F may not be a complete safeguard against botulism."
Pesto is certainly a botulism risk if not handled properly. Here's more
I'd freeze the pesto if you are not going to use it within 10 days or so.
"A second important factor affecting the growth and toxin production of Clostridium botulinum is temperature. Proteolytic types grow between temperatures of 55 and 122 degrees F, with most rapid growth occurring at 95 degrees F. Nonproteolytic types grow between 38 and 113 degrees F, with an optimum for growth and toxin production at about 86 degrees F. For these types, refrigeration above 38 degrees F may not be a complete safeguard against botulism."
Pesto is certainly a botulism risk if not handled properly. Here's more
I'd freeze the pesto if you are not going to use it within 10 days or so.
Think I'll keep my pesto batches small. I rather like the idea of pesto that's freshly-made as opposed to pesto that's thawed after months or a year in the freezer.
bethzaring
Master Chef
for me, pesto making is a bit of a production, I make about 5 cups at a time. I keep between 1/2 pint and one pint in the frig and freeze the rest in 1/2 cups piles on waxed paper...when frozen I roll up the pesto blobs in the wax paper and put in a freezer bag. I can not detect any difference between the fresh and frozen pesto. I do not know why it is such a production, have roasted nuts on a waiting tray, olive oil drizzeled about, garlic wrappings stuck to my fingers, parmesan cheese clinging to the measuring cup and basil littering the sink area. I just do not want to do this very many times a season, about 5 times is all I can handle. I LOVE pesto available any time the mood strikes.... I never have pesto in the freezer over 9 months, I use it in too many ways
cara
Master Chef
jennyema said:
*lol* thanks for the link... I searched german Google with the same (german) words and it brought me no countable results, there was only one page that said Botulism was found in pesto somewhere in the US...
the rest was a waste..
jennyema
Chef Extraordinaire
Any fresh thing grown in soil which is kept in an anerobic environment without being heated or acidified is a suspect, I am pretty sure. The soil can contaminate the product and then the spores grow in the anerobic environment if kept at "danger zone" temps.
I agree with Beth that frozen pesto tastes pretty close to fresh.
I agree with Beth that frozen pesto tastes pretty close to fresh.
