My tweaked pesto recipe to delay spoiling

I've been making many pounds of pesto this winter and freezing single serves.
Five months prior, I discovered that it is so simple and quick to grow basil from seed.

I love how easy and energy-efficient it is to reheat some leftover pasta with a glob of pesto and some fresh garden veg and serve, takes 1minute in the microwave - no prep.
I'd read that you can mix a lot of parsley and coriander into home-made pesto and sure enough, it bulks it out without affecting the strong taste of basil.
Holy basil and a little mexican coriander can also be added to the mix.

Substituting other nuts (I like toasted macadamia, bunya or walnut) saves you the money and packaging of buying pine nuts. [$60/kg is nuts]

Making it last longer:
1. Don't add cheese to the pesto - if you want cheese, add it when serving. (And use standard cheese, the Parmesan twang can be provided by citrus)
2. Don't skimp on the oil - when saturated with oil, it acts like a protective film.
3. If you need to add water (only sometimes needed) use boiled water.
4. Use a good amount of lemon or lime juice - the citrus twang is overpowering (even unpleasant) for a day or two, then the taste mellows enough to enhance the flavor, then it seems to accelerate the browning of the pesto for a few days (which looks bad), but then it seems to act like a preservative (presumably from the acetic acid).
[Vinegar probably works too]

This pesto stays good (if a little brown) in the fridge for at least 12 days and that is without an airtight container.
When I'm trying to make it last two weeks, I'll scald the spoon I'm using to scoop out a serving and try not to exhale towards an open dish of pesto.
Alternatively you could cover the pesto with half an inch of olive oil for longer preservation, but I think pesto is oily enough without being drowned in more.

Pesto for me is a strongly flavored green paste that's got flavor from basil and other powerful green herbs, plus richness from nuts and cheese and oil.  However since I don't eat animal products or (very much) refined oils, I have done a lot of experimenting with various herb+nut combinations.  I agree that a bit of citrus/acid helps with preservation, but usually I eat it fast enough that preservation hasn't been a problem for me.

I wanted to add a couple of ingredient suggestions.  Mustard greens  -- one year I was buried in them -- is something that makes a good pesto, alone or mixed with lots of basil.  (Mixed with basil is better in my opinion.)  Pecans are a very tasty nut to use.  (They grow wild here, so in a good year we have them in high surplus.)  

It is also possible to blur the line between pesto and hummus, with gustatorily useful results.  Chickpeas add richness when you aren't using cheese or oil.  Tahini (sesame paste) or peanut butter can fill in relatively inexpensively for more expensive nuts.  If you eat soy, a bit of silken tofu is another thing that can fill some of the texture left by missing oil and cheese.  Obviously if you use oil and cheese, they are superior.  

Jondo, I apologize if I took your thread sideways from the "tweaks to avoid spoiling" direction and just started on "tweaks generally".  But tweaking pesto is something I really enjoy doing.   Late summer basil plants that JUST WILL NOT STOP  are a joy and a challenge to keep up with.

Hmmm, hommus-pesto sounds like a rich delight. (Pestus? No, it'll have to be Hommsto)

Thanks for the input, Dan.
Have you tried using whole peanuts or just PB? I'm not sure my cheap stick-blender could handle PB.
I've been considering tahini as a nut substitute, but I'm trying to go for the least packaging and processing.
I want to stress that macadamia adds something special (both taste and mouthfeel) and toasted bunya nuts are out of this world flavor.

While tree-nuts are universally expensive, they are ethical purchases being perennials with far less inputs than annual agriculture.

Theres lots of recipes using spinach, kale etc in place of basil.
I'm more curious to try a pure parsley pesto or a pure coriander one (which might be better as a sandwich spread or marinade than a pasta dish).

I can't stomach basil on its own and don't have many uses for it besides pesto.
I guess a lot of people can't grow basil through winter, but if you can it satisfies the hunger for rich pasta meals.

It surprised me that my basil seed all germinated in <1 day, even quicker than radishes.
Definitely a good instant-gratification plant to grow from seed and hardy enough to deal with poor quality potting mix and a scorching balcony or veranda.

Jondo Almondo wrote:Have you tried using whole peanuts or just PB? I'm not sure my cheap stick-blender could handle PB.

For my kitchen gear it seems to go the other way ... I find peanut butter easier to blend (with other wet ingredients) than whole peanuts, which remain gritty in anything short of a high-end Ninja-type high-speed blender.  Likewise sesame seeds, which remain gritty and only half-ground no matter what kitchen machine I throw them at; I've found no substitute for buying them preground as tahini paste, although I did find one store that sold a tahini that was nothing but ground sesame, no other ingredients.  

Jondo Almondo wrote:I'm more curious to try a pure parsley pesto or a pure coriander one (which might be better as a sandwich spread or marinade than a pasta dish).

 Have you Googled chutney recipes from India?  I heard an NPR broadcast of The Splendid Table where an Indian chef was talking about a cilantro chutney that seemed to consist primarily of blended fresh cilantro and (I think) a few peppers; I can't remember the details but I have been meaning to research further.  It sounded like a fresh green sauce in the category we are talking about, from an entirely different culinary tradition.  It seems to me the broadcast discussed storage options for the chutney, too, which would be germane to your original post, but I have forgotten those details.  You might be able to Google up the podcast; the primary dish under discussion was a fried sandwich similar to a toasted cheese, only the filling was flavored yogurt and the outside of the sandwich was dressed in fried curry leaves.  (The cilantro chutney was a recommended condiment.)  

Jondo Almondo wrote:It surprised me that my basil seed all germinated in <1 day, even quicker than radishes.
Definitely a good instant-gratification plant to grow from seed

Wow, what an utterly different experience we have with the stuff!  For me, I have to sow dozens or hundreds of seeds divided among six or eight different pots, beds, and circumstances, in hopes of getting just five or six plants that will actually germinate and survive to the size of two or three inches tall -- a process which can take weeks, and sometimes multiple efforts.  Once I get those half-dozen robust plants, though, I'm golden -- they love my conditions and will boom heartily until first frost, which occurs in November.  I am just now breathing a sigh of relief as my basil for this year has reached the magic "it's gonna make it size" for 2019.  So I am solid for six months, as usual.