Can You Reheat Pesto Pasta?

It's perfectly safe to reheat pesto pasta, provided it has been refrigerated within an hour of being cooked and is no more than two days old. It won't be as good as it was fresh, but in a bizarre twist, the reheating process can even make it healthier for you.

Reheating pesto-pasta is perfectly safe

We've previously outlined our preference for only heating fresh pesto using the residual heat from the pasta rather than applying direct heat from your hob, oven, or microwave. When it comes to reheating a pesto pasta dish, though, it's perfectly safe, provided it has been refrigerated and is no more than two days old. The taste and texture just won't be quite as good as when they were fresh.

Why reheated pasta can be healthier for you the second time around

In 2014, a study by the University of Surrey discovered that there's something quite remarkable happening behind the scenes when you reheat pasta. This is not only good for your blood sugar levels but can even result in you absorbing fewer calories.

Let's have a quick science lesson.

When your body starts to break down a high-carbohydrate food like pasta, it causes a sudden spike in blood glucose levels, prompting your body to create insulin to bring everything back to normal. The body is pretty good at doing that, almost too good because when your glucose levels return to normal, you start to feel hungry again. That is why dieticians are constantly nagging us to switch to wholemeal carbohydrates; they are higher in fibre and take the body longer to break down.

It turns out that cooking, cooling, and then reheating pasta changes the starch's structure to become what scientists call a resistant starch. That means the body treats it like high-fibre pasta, meaning you don't get the same glucose surge. That's great news for people with diabetes, but it's good news for everyone else, too, because the process can even result in you absorbing fewer calories.

The best ways to reheat leftover pesto pasta

If, after reading this, you're tempted to whip up an extra couple of servings of pasta for reheating the next day, we strongly advise keeping the pasta and pesto separate. That will mean you can simply warm the pasta for 30 seconds in gently simmering water before combining it with the pesto in the same way you always do. If, however, you've accidentally made too much and your pesto and pasta are already mixed, you have a few options...

Sauté or stir-fry
You already know we don't usually condone heating pesto on the hob, but in the case of leftover pesto pasta, a quick sauté in a wok or saucepan with some vegetable oil is perfectly fine.

Microwave
Add a couple of teaspoons of water to your leftover pasta, cover with cling film, and microwave on the reheat setting for 30 seconds. Stir the pasta, return it to the microwave, and continue until it is piping hot. It's not a Michelin-starred technique, but it works.

Bake in the oven
There's no shame in oven-baking leftover pesto pasta. It completely changes the texture, but in a different way, not necessarily in a worse way. Covering your pan with tinfoil will limit moisture loss and help prevent the pasta from burning on the edges. It should take 10-12 minutes to cook in a 180°C oven.

A quick note on air fryers and pressure cookers
We all know air fryers are fantastic at creating the crispiest, healthiest chips, but they are hopeless at reheating foods like pesto or pasta. As for pressure cookers, you could use the 'warm' function, but it's a waste of electricity compared to the much better options outlined above.