by Michael Hawkins
Short answer
No, you should never heat fresh pesto before adding it to pasta, although with the jarred alternative, we're a little more relaxed.
Long answer
We're often asked whether you're supposed to heat up pesto, and 99% of the time we advise against it, especially if you're talking about the kind of fresh pesto you find in supermarkets' chilled sections.
The reason is because pesto is designed to be a raw sauce. Cooks and manufacturers go to great lengths to preserve the freshness of the ingredients, so heating up your pesto just destroys all that hard work.
This is not to say pesto must be eaten cold. If you're serving pesto with pasta, for example, once you've drained your pasta and stirred through the pesto, the pasta's residual heat will naturally warm the sauce without the need to apply any additional heat.
Ambient pesto, on the other hand (the kind you find in the pasta aisle of your supermarket, sold in glass jars with a long shelf-life), is slightly different. For this kind of pesto to be edible for so long, it will have undergone some form of heat treatment.
Here at GO! Pesto, we go to great lengths to keep this kind of heat treatment to an absolute minimum, thereby preserving as much freshness as humanly possible. However, while we don't condone heating fresh pesto, we're a little less opinionated when it comes to the jarred stuff.
In fact, we've got lots of recipes where the sauce is heated. This includes pasta bakes, paninis, pizzas, and many more. Just be aware that exposing pesto to too much heat for too long will change its flavour. Whenever possible, therefore, we add it right at the end of the cooking process to minimise any flavour loss.
