Okay, I am writing this question as a result of a long experience in trying to make pesto at home :p I like pesto sauce alot and that is why I have decided that I should make this at home. But for some reason when I make the pesto sauce I almost completely lose the flavor of the basil. It tastes more like oil. And yes I have tried varying amounts of oil and basil and still it tastes atmost like oil with grass in it. Here are more details:

1- I stay in UK at the moment so my basils are nearby and they seems to be grown in Wessex if what is written on them is true. When eaten as a leaf they have quite alot of flavor.

2- I have tried using a blender, mortar and pestle and also manual chopping to create the basil paste. After the chopping is complete, I tried tasting the basil paste before mixing it with oil and other ingredients and it tastes like grass more or less, with very little flavor left. I wash the basil leaves before making the pesto as the package itself says so. I use the mediterennian type basil.

3- It tastes slightly better when it is cooked a little bit or left in oil for some weeks but I have seen instances where freshly made uncooked pesto also tastes great, so I must be doing something wrong.

4- I have never grown the basil myself however to increase freshness I have tried buying already grown basil plants in pots.

Since I have exhausted all possible methods of pesto making it seems to me that either:

a- Since its quite rainy and not so sunny in UK the basil leaves from here have too much water content and to little plant oil content and they need to be dried for some time before being chopped. This might be supported by the observation that when I chop them on wooden board I get quite a lot of wetness marks on the board. And when I use fresh basil from the pot they are usually well watered.

b- UK basil is not good for pesto?

c- I am somehow mistreating the basil, I should put much less pressure when using a blade or mortar.

Any suggestions is most welcome :)

  • 1
    You don't mention any other ingredients besides basil and oil; Do you also put pine nuts and parmesan, to complete the classic pesto recipe? Do you use a high quality, extra virgin olive oil? Aug 14, 2016 at 14:41
  • I use pine nuts yes. I havent tried roasting them but I will. I use extra virgin olive oil though not italian one. But the problem is that even before I put the chopped and meshed basil into oil, it really has not basil taste left in it. It tastes like grass.
    – Sina
    Aug 14, 2016 at 14:48
  • Okay, just making sure :) I'm from the Netherlands, and I'm quite sure we don't do much better over here weather wise. And I have no problems using "Dutch" basil, UK basil should be the same or similar, I suppose. Aug 14, 2016 at 14:57
  • 1
    Hmm. I make (food processor) basil pesto of some sort every year. Often without cheese (we freeze, mark it as "NC" and add cheese after thawing.) Sometimes without nuts, often without pine-nuts as they are incredibly expensive these days. Usually with garlic, oil and lemon. Have never had a batch that tasted like grass, not basil. NE USA, homegrown basil. We also pesto-ize garlic scapes (not with basil, it's not ready yet when they are.)
    – Ecnerwal
    Aug 14, 2016 at 16:13
  • 1
    Possibly blending too long and cooking the stuff? That's a flavor killer. Aug 14, 2016 at 23:25

2 Answers 2


I don't have a definite answer, but here are a few thoughts on things that might help.

First, are you drying the basil after washing it? Shake out the extra water, and pat it dry, maybe let it sit for a bit to evaporate. The extra water will dilute the pesto a bit, and not be good for the flavor - and if you think the problem might be too much water in the basil, no need to make it worse with extra water on the surface.

Also, are you adding basil stems? Depending on your variety of plant and the steps you take in your recipe, the soft stems or tips might have more flavor that you're loosing by leaving out, or more plant matter to dilute your basil paste if you leave them in. Taste the stems, and check your process, and consider if it would help to take the stems out/leave them in once and see if that helps.

Also, it might help to check your salt content. Some pesto recipes use salt, others use salty cheese, I don't know what your recipe calls for - but salt brings flavors out, and one symptom of under-salting is "watery" flavor, so you might just need a bit more. Adding salt might help your basil paste taste like "basil" instead of "grass".

I was wondering, given your comment on seeing a lot of water on the cutting board from the basil, if you might be losing flavor from the basil juice when cutting. Preparing the basil on the cutting board seems the method most likely to have this problem, but even if using the mortar, if you crush ingredients separately then mix in a different container, you might be losing some of the flavor in juices. On the other hand, most blender recipes (and some mortar and pestle ones) make the pesto in one container, which means the flavor should still be in the mix and not lost- so that might not be the problem, or at least not the only problem.

If the basil is just too mild for your tastes, or has a higher water/flavor oil concentration than you'd like, you might be able to address this by letting the basil dry a little, maybe till wilting, before making pesto to concentrate the flavor a bit. You might also consider adding some dried basil to strengthen the flavor - I would think completely dried basil would not give the right consistency, but a mix of fresh paste and dried flakes might give the flavor profile you're looking for.

If the basil tastes like the basil you expect when you take a leaf and taste, and grass after it's made into paste, then the flavor must lost somewhere along the way - then you can look at your process and guess where the flavor is going (like sap left on the cutting board, or whatever). If you taste the leaf and find it doesn't taste basil-y enough to begin with, then it might just be you prefer a stronger basil or a different variety, and doctoring your basil paste with flakes (or even other herbs/spices) might be the only way to get the pesto you want if no other basil varieties are available to you locally.

  • When not board I also use a wooden mortar. So I will try to do in some durable glass cup today (no marble ones available atm). I will also be more gentle when using the mortar and pestle. If this does not work out I will also try drying the leaves half a day prior to using them as you advised. I will come back with some results in a few days :p
    – Sina
    Aug 14, 2016 at 17:40
  • @Sina - Hopefully, this will fix the problem. I look forward to hearing how it works out :)
    – Megha
    Aug 14, 2016 at 18:16
  • I agree on the salting (especially in a mortar & pestle, as it helps grind things up), but I don't agree on the wilting. Old basil loses flavor. What you can try is blanching & shocking the leaves, then place them in a pot and cover with olive oil ... heat over low heat, and let it sit on warm for an hour or two, and then strain the oil, and keep it in your fridge. It captures much of the basil flavor. You can then either use it make pesto (either with basil, flat leaf parsley, garlic chives, garlic scapes, etc.), or in other recipes.
    – Joe
    Aug 15, 2016 at 12:58
  • 4
    After several more attempts I can probably confirm that uncoditioned wooden equipment soaking the juice from the basil was the problem. I made several more batches using a wooden pestle and ceramic bowl and it tasted and smelled much better. Ceramic bowl being very smooth makes it a bit harder to crush the leaves, even with salt. But the end result is very worth it, I get alot juice from the basil. Also roasting the pinenuts result in a really good smell when crushed with pesto, just smells like the ones I had in Italy.
    – Sina
    Aug 21, 2016 at 20:12
  • @Sina - I'm glad you figured it out! Your pesto sounds really good. Thanks for letting me know what helped :)
    – Megha
    Aug 22, 2016 at 0:05

I prepared basil three ways, dried in a microwave for a short time, chopped and frozen in zip lock bags and they tasted fine on a tomato salad....but the third time I used a blender with olive oil...it yielded a very fine paste with a grassy flavor...I think the pureeing breaks down the cell wall structure and releases chlorophyll and other components that give an off taste....I think brief pulses in food processor and not liquefying the basil as the blender does would give a better taste.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.