My Goals

  • A soup with heft

  • Perfectly cooked squash

  • A flavorful, velvety base

  • Balanced savory flavor and bright finish

A cup of pureed butternut squash soup is fine as a dinner starter or as a side to a sandwich. But this winter I wanted a heartier soup that I could enjoy as a stand-alone meal. I’ve seen a few versions that pair chunks of squash with creamy cannellini beans, which sounded like just what I was after.

I sautéed sliced leeks, added diced squash and chicken broth, simmered it all for 10 minutes, added the beans, and simmered a little longer to warm them through. I wanted simple, but this was too simple, as the soup was thin in taste and texture. Furthermore, the squash had cooked unevenly.

What is the ideal consistency for a hearty, stand-alone squash soup? To find out, we prepared and tasted several versions, each with a different appearance and texture.

There was one clear reason for the uneven cooking: It’s easy to evenly dice the neck of a butternut squash but not the bulb end: I ended up with oddly shaped bits. I could cut the bulb into equal pieces if I made them larger, but tasters found these unwieldy to eat.

Dicing the squash into even pieces lent the soup appealing texture and bite, but since the neck of the squash is denser than the bulb, we needed to find a way to cook them both evenly.

The flesh from the squash neck is also much more dense, and thus slower to cook, than that of the bulb, which tended to blow out and turn stringy. I tried cutting the neck into smaller pieces than the bulb to equalize their cooking times, but the oddly shaped bits of bulb nagged at me. Then a fellow test cook made a suggestion: Why not cut the bulb into wedges, cook these in the broth until they were completely soft, and then mash them to create a “squash stock” for the soup’s base? Then I’d cook the diced neck pieces in the stock. Good idea—this gave my soup body and flavor and avoided the issue of uneven cooking.

Making a stock from the bulb of the squash was one of the keys to our soup’s rich consistency.

But the soup had a one-note sweetness from the squash. Two of our favorite umami boosters, soy sauce and tomato paste (along with some minced garlic), lent needed depth. Sautéing tomato paste with the leeks deepened its flavor further.

My soup still tasted lean, though, so I tried drizzling it with olive oil. Unfortunately, the oil didn’t provide the infusion of richness I was after. Cream was a poor fit in this brothy soup and muted the flavors. Then my mind drifted to the technique of enriching sauces by whisking in butter toward the end. Adding butter at the end would be difficult given everything in the pot, so I added it to the stock at the start of its cooking. The lengthy agitation of the simmer fully emulsified the butter, no fussy whisking required.

For a final touch I prepared a sage and walnut pesto to swirl into the soup at the table. This was just the satisfying, hearty main dish I’d set out to make.

Keys to Success

  • A soup with heft

    To make our soup hearty and meal-worthy, we cut the dense neck portion of the squash into chunks and add creamy cannellini beans to the mix.

  • Perfectly cooked squash

    Since the bulb portion is difficult to cut into tidy cubes and cooks more quickly than the neck portion, we avoid the issue of uneven cooking by cutting the bulb into wedges, simmering them in broth, and then mashing them to make a “squash stock.”

  • A flavorful, velvety base

    The squash stock gives our soup both a velvety texture and more flavor. Adding butter to the squash stock at the start of its simmering time allows it to fully emulsify, giving the base more body and richer flavor.

  • Balanced savory flavor and bright finish

    Tomato paste, soy sauce, and garlic add savory notes to balance the sweetness of the squash while a sage-walnut pesto, quickly prepared in the food processor, gives the soup an herbal, fresh finish.