I started making this pesto quite a few years ago when I had a particularly prolific basil plant on my balcony. One plant grew into a basil tree and I wish I had taken pictures at the time. The colder weather was nearing and I brought it inside but was woken up in the middle of the night by the overpowering scent of basil. I didn’t want it to go to waste, or lose it when the frost hit, so I whipped up a batch of freezer pesto and passed a couple jars around the office. Why, you might ask, did I decide on “freezer” pesto? Well, first of all, I don’t really care for pesto that has a lot of oil in it. Secondly, you may have noticed that when you chop up basil, it oxidizes and will quickly turn black (looks very unappetizing) so I thought I would try freezing it. I had passed out a few jars at work for some feedback. It turned out to be so successful that a co-worker offered to split the cost of picking up the ingredients if I would make another batch. She had quite a bit of basil in her garden and fall was drawing near so it would be a great way to use it up before the frost killed it all. I remember her bringing in a huge garbage bag full of basil, roots and all. She had sold her house and I guess it just as easy to pull up the plants as cut them. In any case we certainly had plenty of basil for the recipe and a trip to Costco would get us the rest of the ingredients.
A few years after that first round of testing, I found out that the mother of one of my friends had actually kept a jar in her freezer for 2 years, thawing it, taking some out then refreezing it. While I don’t suggest going to that extreme, you can thaw it out, take out a portion and put it back in the freezer at least a couple of times, or you can simply put the pesto in smaller jars so you won’t have to. The important thing is that when you do open a jar of this pesto, you should add a bit of olive oil to cover the surface and you have to use it within 5 maybe 7 days because it will turn black and look gross.
When I make this pesto, I like to use a mortar and pestle to grind the garlic and nuts first but you can easily do this all in a food processor. There is a LOT of debate over which method is better: mortar and pestle vs food processor. The main point of the debate is that using a mortar releases the oils of the nuts and garlic much better than chopping it all in a processor. I like to use both methods. It can actually be rather therapeutic if you’ve had a frustrating week or want to get a good arm workout without going to the gym. If you decide to use the method that I do, just make sure that your mortar is large and that the inside of the bowl has a rough texture.
Make sure you have more than enough jars on hand and that you have sterilized them in a hot water bath (ie. boil some water in a big pot and put your jars and lids in for 5 minutes or put them through a cycle in your dishwasher). I made the mistake of assuming I had enough jars and had to run out to hunt for more. Fortunately, I was making the pesto in batches and realized that I did not have enough jars for the last 2 batches. This being canning season for a lot of people, I had to run to several stores hunting for small jars. It was a good thing I had not added the basil because who knew how long it would have taken to find enough jars before the basil would have started to oxidize and turn black.
What you will need:
Mortar and Pestle and/or Food Processor
Freezer Basil Pesto
6 large bunches basil (1,440 ml or 32 cups),
750 grams Grano Padano parmesan cheese (approx. 1.75 pounds)
700 grams walnuts (approx. 1.5 pounds)
200 grams pinenuts (7 ounces)
500 grams almonds (approx. 1 pound)
3 heads of garlic
1 litre olive oil (34 ounces)
(maybe a bit more depending on how thick you would like your pesto)
Coarse sea salt
2. Clean and prepare garlic. Cut end off bottom and crush slightly with the flat of a knife. Skins will be easier to remove.
3. Wash basil thoroughly and remove leaves from stems. Discard stems and any flowers. Divide into approx. 2 litre (8 cup) portions
4. Using a mortar and pestle, pound garlic & nuts with a sprinkle of coarse sea salt in batches. If you are not going to do this step, you can process the nuts and garlic using a food processor.
5. Divide nut/garlic mixture into 4 portions (approx. 470ml or 2 cups for each batch)
6. Put portion of nut/garlic mixture in food processor and add approx. 2 litres (8 cups) of cleaned basil leaves
7. Add 470 ml (2 cups) grated parmesan cheese
8. Gradually add 240 ml (1 cup) of olive oil (more or less depending on how thick/thin you like your pesto)
9. Put in cooled sterilized jars making sure there are no air pockets and leaving enough space so that there is 6-8 millimeters (¼ inch) from the top after adding a drizzle of oil to cover the pesto. Put lid on and place in freezer.
This recipe made approx. 20 1/2 jars of pesto depending on the size of jars that you use. I used 12 x 250 ml (8 oz jars) and 8 x 125 ml (4oz jars) but had a bit left over that I used for dinner that day.
Thaw in refrigerator when ready to use. Once opened, make sure you add enough olive oil to cover the pesto and use within 5-7 days or it will turn black. The layer of olive oil creates a seal to prevent the basil from oxidizing. Or you can return the jar to the freezer after you have topped up the jar with a bit of olive oil to cover the remaining pesto.
It’s great on pasta of course, but you can also toss it with grilled veggies, spread on slices of toasted baguette and add a bit of goat cheese, slather it on top of salmon and grill it, use it as a spread in a sandwich or on pizza… so many options! Enjoy!!