Thursday, July 5, 2012

A Pesto Primer

First let me banish any misconception that pesto refers only to the concoction using fresh basil as the major ingredient. The word pesto simply means anything that's pounded, so you could have pesto made using artichokes as the base, or olives, or even celery for example. For this post, it's all about the basil though, and the classic pesto alla genovese, from the region of Liguria. It may come as a surprise to many of you, but the traditional pesto alla genovese is frequently served using trenette or linguini, and includes potatoes and green beans, cooked in the same water as the pasta. Alternatively, another authentic shape of pasta used in Liguria, is the little twisted squiggles called "trofie" - more on those below. 

My friends from Liguria tell me that the smaller leaf basil provides a much more flavorful pesto, but I never actually put it to the test - until now that is. My friend Dorothy, whom I've written about before here and here, is responsible for creating a vegetable garden at a local elementary school in Princeton. This year, she received a generous gift of 45 basil plants from Cross Country Nurseries in Rosemont, N.J. 

Among the plants are several varieties of small leafed basil, including the ones below that I harvested to make the pesto in the first photo.

 Here's a photo of part of the garden, including some of the various basil plants. I never knew there were so many varieties of basil. Cross Country Nurseries carries 94 different varieties -- from lemon basil, lime basil, cinnamon basil, anise basil and many others -- all with different aromas and tastes.

This is just one of the purple leafed varieties.

This one's serrata basil.

I think this was an anise flavored basil.

This is a lettuce-leaf basil, and Dorothy says it's great for using as a wrap instead of bread. I can't wait to experiment more with some of these varieties - in salads, in main dishes, even in desserts. But for now, it's back to the small-leafed variety for the pesto.

The classic pesto alla genovese uses pine nuts, but I couldn't find any European pine nuts locally (next time I'm in Philly I know I can get them in the Italian neighborhood on Ninth Street). I'm not eating Chinese pine nuts, since so many people have reported pine nut syndrome as a result. As a substitute, I used pistachios, something I've been wanting to do since I ate a fabulous pistachio pesto at Le Virtu in Philly. Make sure you use good quality extra virgin olive oil too. This one was from Casale Sonnino, a villa and farm owned by friends of mine in Italy. It's simply the best, and you can be guaranteed that it's unadulterated oil from olives on their property outside Rome that they take to the mill themselves. They take orders, and also rent out their villa to vacationers, so check out their website here. 

I figured since I had the tiny leaf basil, why not try to make pesto the way it's been made for centuries in Italy -- using a mortar and pestle. Decades ago, my brother-in-law gave me an antique mortar and pestle that was actually used at one time as a pharmacist's tool, and maybe I should have just kept it on the shelf. After years of use, it cracked last year while I was pounding something in it - I don't remember what. I do use a mortar and pestle occasionally for crushing rosemary into paste and sometimes to break up hard seeds like coriander or black pepper corns. So this year, I replaced the old antique apothecary's mortar with another marble one - from Williams Sonoma

It really takes a lot of elbow grease to pound those little leaves, garlic, salt and oil into a paste. Enlist the help of someone if you can and take turns (or surrender to the food processor).

When it's sufficiently pounded (or sooner if you can't go any further), boil the potatoes and add the green beans and the pasta in the same water after the potatoes are about 10 minutes from being done.

Drain everything and mix with the pesto and a healthy handful of parmesan or pecorino cheese. I can say that the small basil leaf was very flavorful and pungent, and along with the pistachios, I didn't miss the pine nuts at all. But one thing that always bothers me is how quickly the pesto goes from bright green to a drab olive green. 

So I set off to do an experiment of blanching the basil leaves before making the pesto. This time I made the pesto using my first harvest of the season from my garden - of the regular large-leafed variety.

My neighbor's daughter Janie was my sous chef, helping me pluck the leaves from the stems.

We blanched the leaves in boiling water (count to 10 and then remove the leaves).

Immerse them immediately in an ice water bath.

Squeeze the water out of the leaves.

And this time I used the food processor, not the mortar and pestle. The color was a vibrant green.

Check out the difference in the colors of the basil - on the left is one made with non-blanched leaves and on the right one made with blanched leaves.

Insung and her daughter Janie were impatient to taste the finished product, but bloggers have to get those pictures first! This version was made using toasted almonds instead of pine nuts, and trofie pasta.

Normally, when the pesto hits the hot pasta, the color darkens to a drab green, but blanching helped it keep its bright color for quite a while. 

Now that basil is flourishing in gardens everywhere, make sure you make enough pesto to put away for the winter. It freezes beautifully, provided you omit the cheese until you're ready to serve.

Pesto Alla Genovese

printable recipe here

The amounts aren't exact. A lot depends on how firmly you pack the basil into the measuring cup, how large the garlic cloves are, and of course, your taste buds.

4 cups basil, loosely packed

2 large cloves garlic

1/4 cup Italian pine nuts, toasted, or pistachios (salted or unsalted), or toasted almonds or walnuts

extra virgin olive oil - as much as two cups, as needed to obtain a loose pesto.

1/4 cup - 1/2 cup parmesan cheese (or pecorino if desired)

If using a food processor: Tear leaves from stem, wash, dry and place in a food processor, along with the garlic, nuts and a small amount of the olive oil. Start with 1/2 cup and keep adding more until it flows smoothly when you dip a spoon into it, but not so thin that it falls off in a stream. Use your judgment.

Add parmesan cheese if serving immediately. If you're planning to freeze it, don't add the parmesan cheese until after you defrost it and are ready to serve.

If using a mortar and pestle, start with the washed and dried basil leaves, garlic and nuts and add a small amount of coarse salt to help break down the leaves. Pound with the pestle and slowly add a little bit of olive oil. Keep working the mixture with the pestle and add the rest of the oil as needed. The process takes a lot of patience and time.

Bookmark and Share


  1. I got excited when I saw your post, I adore basil, I have 15 plants, basil is coming out of my ears right now! I do blanch my basil first I saw Michael Chiarello do it a long time ago and you're right it does keep bright green. I want to look for that lettuce leaf basil for next year and great tip on the smaller leaves!

  2. What a beautiful garden! I lobasil and pesto. I've never had that small leaved basil...



  3. Look at all of those different types of basil!!! Loving it.

  4. Yep, most anything can be pounded into a pesto. Last year I used fennel fronds and it was excellent. This year I am eyeing a friend's gigantic asparagus patch!

  5. This comment has been removed by the author.

  6. Gorgeous basil photos! My basil is getting very tall so it is time for me to make some of this.

  7. I have never blanched my leaves! I am going to do this from now on!
    and pistachios? Sold! I have been using walnuts because I am afraid of pignoli nuts lately.
    Thank you! xo

  8. Great photos of the different varieties-I want to find some of the curly leaf. Thanks for the tip about blanching-I never do that!

  9. Dear Linda, What a beautiful garden and a delicious looking dish. Blessings dear. Catherine xo

  10. Basil pesto is my daughter's favorite pasta sauce!

    My husband's Genovese aunts and uncles also told us on a visit to only use the smallest leaves of a basil plant for the best, most intense flavor when making pesto. I grow regular, Thai and lemon basil plants -- I never saw the small leaf basil plant before -- that is a nice variety!

    It is so hard to find domestic or Eurepeon pignoli nuts amywahere --even in the best Italian import stores! I never knew about the "pine nut syndrome" but I don't trust a lot do Chinese imports -- did you notice that most supermarket garlic is also imported from China? I've been subsituting walnuts in my pesto with good success, but I'd love to try pistachio nuts next time.

  11. Well what a wonderful post. Basil always says summer to me. As I read I imagined how wonderful your kitchen must have smelled as you and your neighbor were at work.

    And indeed, those small leaves make a fine pesto - they take a bit more work, but I think it is well worth the effort.

    And aren't all the different varieties something? They really are all different, and it is quite remarkable to smell and sample each one.

    Thanks for another terrific read!

  12. I just saw another article on blanching the basil to keep pesto beautifully green! Great idea. I can't wait for my basil to get prolific enough to make some.

  13. I love using the different basils. I actually do freeze the pesto with the cheese and an extra layer of olive oil to preserve greenness. When I am back cooking I shall try blanching the basil. And yes, only Italian pine nuts.

  14. Great tip about blanching! Never knew…

  15. LInda, this is one of the absolute BEST posts of information on basil that I have EVER read! I had no idea what blanching basil would do to the color! I will most definitely follow this tip this summer when I freeze my pesto. I also had no idea that the smaller leaved basil has more flavor --- how American of me to assume the larger leaves have more flavor! I could just die for that garden of your friends too! Thanks for stopping by today. Your blog is truly one of the best going! xoxox Roz

  16. non avevo mai visto tanti tipi di basilico, bellissime foto Linda!

  17. Such a beautiful vegetable garden. Love pesto!

  18. I have some of the tiny "globe" basil growing this year, Linda, and it is so beautiful. I will have to make some pesto with it after seeing yours. The leaves are so tiny, they don't have to be cut or ripped for salads. And I love your travel photos - have a wonderful summer!

  19. Such bright and beautiful pesto! I could eat the bowl of pesto spaghetti in seconds!

  20. New follower! I love this blog! I'm so excited you shared this. I've got fresh Basil coming up now!

  21. Ha! Linda, did you see the 2013 May June issue of Cook's Illustrated? Their Kitchen Notes section, page 50, has a piece "Keeping Basil Green in Pesto" in which they discuss blanching. M'dear, you scooped them. How cool is that?! You article really is wonderful, required reading for pesto season. Well done!

  22. Hi Linda, This is a very informative post. Thank you. I regularly freeze small quantities with the cheese already in for later use and it seems fine. Although it's winter here in Australia, I have come home from Italy to a lush herb garden and there's still basil, but I think the fresh young leaves make a nicer pesto for sure. I always use the food processor! Is that a mortal sin in the Italian kitchen? Ciao for now, MLT