Why chopping nuts is easier when they're hot

Have you ever tried chopping peanuts and walnuts and just being frustrated with them jumping over literally everywhere? Nuts are quite hard, so not the easiest foods to chop into pieces for sure.

However, there’s a really simple trick for chopping nuts that I “discovered” a little while ago when trying to chop yet another batch of nuts (hazelnuts this time). Recipes often call for chopping nuts and roasting them. In a lot of cases you’re asked to chop the nuts first and roast them after. However, I discovered it really is a lot easier the other way around! If you first roast the nuts (or, if you don’t have to roast the nuts, just heat them up) and chop them next. It’s simple, but effective and we’ll explain you why it works, so you’ll likely never forget anymore!

Why chopping hot nuts is easier

In order to understand why this works so well we’ve have a look at the composition of nuts. Most nuts contain a lot of fats. Cashew nuts and pistachios contain over 40% fat, macadamias and pecans well over 70%. As such, fats make up an important part of the structure and texture of nuts.

At room temperature, a large part of the fats in these nuts are solid. This is what contributes to the hardness of a nut. This gives nuts their crunch and structure (alongside the regular turgor mechanism and fibers).

However, have you noticed you freshly warm roasted nuts don’t have a lot of crunch at all? Instead, they tend to be soft and gooey, not at all what you would expect. This is because in hot nuts, almost all of the fats have molten. You won’t see them seeping out of the nuts (although in some cases you will see it to some extent, the nuts will be glossier), the fats are still well trapped within the cellular structures. However, those molten fats definitely soften the nut as a whole.

When chopping foods you are looking for a good balance between being firm enough to slice cleanly. A food that is too soft (like sun dried tomatoes) will make a mess everywhere, whereas a food that is too hard makes it hard to chop it. And once you chop through the hard food, it will likely jump everywhere. Those warm nuts (you don’t even have to fully roast them, just heating them up is fine) strike that perfect balance. Within a matter of seconds I had chopped that warm batch of hazelnuts (a nut especially prone to jumping around everywhere!).

Want crunchy chopped nuts?

So you might wonder, why are cooled down freshly roasted nuts crunchier than the unroasted nuts? Well, this does not have to do anything with those fats in the nuts. Instead, this is where moisture plays an important role. When you’re roasting nuts, you’re heating them up quite a bit. As a result, moisture within the nuts will start to evaporate from said nuts.

Moisture is notorious for making foods un-crunchy. It’s why crispy chicken skin & potato chips should be stored dry and why you don’t want to store a pie with the crunchy crust + moist filling for days. Eliminating moisture helps to crunch foods up and that is exactly what happens in those roasted nuts. Once the fats cooled down again and turn solid, the lower moisture content will have given the nut a perfect crunch.

And, don’t store your nuts exposed to the air in a moist environment! The roasted nuts will pick up moisture from the atmosphere and gone is your crunch!