Tools, Tips, and Techniques: Making and Freezing Basil Pesto

I’m sure it won’t be long before that first frosty night is upon us, so now is the time to do something with your basil plants, as that frost will be the end of them.  It's a shame just to let them go to waste, so a quick and easy solution is to make pesto.  This freezes well, and if frozen in small quantities it can be pulled out and put straight into recipes, or defrosted at a moment’s notice.

The only thing I do differently if I know I will be freezing the pesto rather than using it right away, is to first blanche the basil very quickly in boiling water.  This is an optional step, but it does help to preserve the beautiful green color and the fresh flavor, and it only takes a few minutes extra.

I like to freeze the pesto in ice cube trays and then transfer it to a larger container or freezer bag, that way I can pull out one or more cubes whenever I need them.  The pesto can be kept in the freezer this way for 6-8 months.

Of course we think of pesto mostly as being used in pasta dishes, but here are some other ways to use this versatile sauce:

• Use it on its own or mixed with mayonnaise as a spread on a chicken, salmon, or roasted-vegetable sandwich
• Stir it into vegetable soup to add an Italian flair
• Thin with water and vinegar for a salad dressing
• Mix with mayonnaise and/or sour cream to make a dip for vegetables or chips
• Stir into mashed potatoes or rice  
• If you are a baker, add to bread dough, biscuits, savory muffins and cornbread

Pesto is traditionally made with Parmesan cheese, but it freezes better without it.  You may not even notice it’s missing, but you can always add a bit of grated Parmesan after the pesto has thawed, or if you are adding the pesto to pasta, it’s easy enough to add some grated cheese at the same time.

When using nuts in a recipe, it is always good to toast them first (unless they are going to be in a baked topping).  This really brings out their "nuttiness."  You can sometimes find pine nuts that have already been toasted, which will save you a step.  If not, they can either be toasted in the oven or on the stove top. 

To toast them in the oven, preheat the oven to 350 deg F and spread the nuts out evenly on a rimmed baking sheet;  Toast them until they are golden and fragrant, tossing once.  Check every couple of minutes after the first five, as they will easily burn. 

 If you do not wish to turn on the oven, put the nuts in a dry skillet and cook over a medium heat until they are golden brown, stirring frequently.  Again, one minute the nuts are still pale, and the next they can be burnt, so don’t walk away from the stove if using this method.

Let the nuts cool completely before adding to the pesto.

Here’s how to make the pesto (recipe courtesy of Everyday Food)

Basil Pesto (makes about 1 ½ cups)

Ingredients:

8 cups lightly packed fresh basil leaves (4 ounces)
1 cup toasted pine nuts (see instructions above for how to toast them)

2 garlic cloves, coarsely chopped
Coarse salt and ground pepper

2/3 cup extra-virgin olive oil

Bring 4 cups salted water to a boil; add basil, and submerge with a spoon. Immediately drain in a colander. Rinse with cold water until cool, then pat basil completely dry in paper towels.

In a food processor, combine nuts, basil, and garlic; season generously with salt and pepper. Process until nuts are finely chopped.

With machine running, pour oil in a steady stream through the feed tube; process until smooth.

To freeze, spoon pesto into an ice-cube tray (2 tablespoons per cube). Alternatively, place pesto in a piping bag (or Ziploc bag with corner snipped off) and pipe equal amounts into ice-cube trays. 

Cover with plastic wrap, freeze for a few hours or overnight, then transfer cubes to a container or resealable plastic bag. 

Defrost pesto at room temperature, about 20 minutes (or at 30-second intervals in the microwave). Mash with a fork before using in recipes. If adding to pasta or soup, cubes may be added while still frozen and just stirred in until thawed.