Bitter taste of rocket pesto

Question

I've gone overboard with sowing rocket (Eruca sativa, also known as arugula, eruca, rucola, roquette, etc.) in my vegetable garden... To use up the surplus I've made some fresh salad (recommended), filling some omelets, and also tried a pesto using these leaves instead of the more common basil. My question is about the latter. Basic ingredients I had at hand:

• rocket leaves
• lightly toasted sunflower seeds
• some matured white cheddar
• olive oil
• salt, pepper, chilly flakes, balsamic vinegar

While I quite liked the peppery-tasting result on pasta, my first impression was that this was quite bitter. Not bitter enough for me to avoid in future, but I would be hesitant serving this to someone else.

I've been comparing with recipes on the internet, and those do not seem to differ much. Some add a twist of lemon zest, garlic, some basil leaves, and of course the more traditional pecorino or parmesan. But I don't think enough to dilute the bitter taste.

So I am wondering if other people that have made this sort of pesto have the same reaction of bitterness? If so, do you have any tricks for me to bring down the bitterness to acceptable levels - and would you consider this to be suitable for general consumption (e.g. guests that may be used to different fare than you)?

Answer 1

Rocket has an inherent bitterness and not much sweetness, so any pesto you make from it will have that quality. You can try and balance it with sweetness, acidity, etc but that will only go so far. Basically, if it's going to be too bitter for someone's taste you're better off making something else, or using the rocket's strong flavors in conjunction with something like coriander leaf, cilantro leaf or basil.

Answer 2

Consider adding more salt and fat as both do a good job of cutting through bitter flavors and making them more palatable.

So adjust the amount of olive oil and salt, or find a cheese with a saltier profile than your cheddar for a bit of both.

Answer 3

To avoid bitterness in argula it's a good idea to pick the leaves very young, especially during hot weather. Staggering your planting is a good technique, but this isn't going to help you until next year. Once you've got the bitterness, some ideas:

• A momentary blanch in boiling salt water - literally just a few seconds - can reduce bitterness.

• Salt and fat both offset bitterness. Increase the olive oil, and consider a saltier cheese - parmesan or romano or something along those lines - rather than cheddar.

• If all else fails, dilute the bitterness by adding another herb or green to your pesto.

Answer 4

My practice when making pesto with any pungent or bitter herb (I've done sage and sorrel) is to add parsley to provide a more mellow taste. With sage, I've had to do as much as 1 part parsley to 1 part sage; with sorrel, 1 part parsley to 4 parts sorrel.

Answer 5

Adding sweetness, saltiness, fattiness, or acidity will cut down the bitterness of the rocket. For this application i don't think you would want much acidity or sweetness, so I would add saltiness and fattiness in the form of a more traditional parmesan cheese or just plain salt, and a little more olive oil. Another option would be to embrace the sweet side and make it more of a rocket/sun dried tomato pesto.

Answer 6

Most of the other answers haven't mentioned this: if you are using olive oil, especially extra virgin, then it can be quite bitter. I find you don't taste it so much unless you mix it into a dressing or mayonnaise; if you've ever tasted fresh olives directly from the tree, you'll know they are unpleasantly bitter. The bitterness is reduced during the pipcling process by soaking them in salt water or similar - which demonstrates the bitterness is water soluble and explains why the bitterness comes out when you make a dressing.

Answer 7

This may be an oblique solution to the problem. I have found that a similar garden herb, Diplotaxis tenuifolia (common names: Perennial wall rocket, wild rocket, sand rocket, Lincoln weed, white rocket, wild Italian arugula, sylvetta arugula) is a adequate replacement for most uses mentioned in the original post. Its peppery taste is perhaps a little less strong. It does have a bitter taste too, but when made into pesto, this seems to all but disappear with overnight fridge storage.

So it seems I'm sowing wild rocket in future in stead of the other kind.

Answer 8

Try another herb - unfortunately only available for a few weeks in Spring - Wild Garlic leaves...makes a wonderful and not bitter pesto.. and the usual pine nuts (can be dry toasted) and Parmesan or Grana and either good olive oil or flavoured rapeseed - especially basil flavoured.. I also add smoked garlic!