How to use frozen spinach, an ingredient that deserves more respect

Frozen spinach is sold bagged and in a block. Photo / Scott Suchman for The Washington Post; food styling by Lisa Cherkasky for The Washington Post

OPINION

Pack nutrition into a wide range of dishes with this budget-friendly staple, recommends Washington Post recipes editor Becky Krystal.

Frozen vegetables don’t get the respect they deserve. They’re long-lasting, affordable, versatile and picked and chilled at their peak for optimal freshness and nutrition. Yet people often treat them like a cheat or, worse, lump them in with other processed foods.

Even with as much time and money as I spend at my local farmers’ market, the seasons for produce can be short, and the grocery store alternatives are disappointing, especially after travelling long distances from where they were grown. This is where the value of frozen vegetables, which also often save you prep work, comes in.

I use them in saucy curries and fried rice. Frozen corn is an always-have in our house, as we commonly tuck the kernels into grilled cheese sandwiches (a favourite of my son’s) or quesadillas. Frozen vegetables make an especially convenient addition to soups and stews. You can even roast them, given the right treatment.

If we’re talking about bang for your buck and your time, frozen spinach deserves top billing. Recently, a few readers have taken issue with our use of frozen spinach in recipes, suggesting we should always call for fresh instead. To which I say: Why? The fresh equivalent of a 10-ounce block of spinach can cost two or more times as much. Plus, anyone who has ever had to wilt a ton of fresh spinach knows how it can take multiple batches and minutes to get it all into the pan. And once you do, poof! It shrinks to basically nothing anyway.

Unless you’re flush with spinach from your garden, there’s no reason to twist yourself in knots to spend more money and create additional work when a recipe calls for frozen to begin with. A lot of the work has already been done for you!

Here’s what you need to know about how to make the most of frozen spinach and when it can, and can’t, take the place of fresh.

Types of frozen spinach

Frozen spinach is sold as a brick or in a bag, as well as chopped or still as leaves. The major advantage of bagged frozen spinach is that you can typically pull out a little at a time as you need it. That’s not really an option with a brick. I’ve found that the bagged stuff tends to release a bit less water than the block once thawed and may give you more distinct “leaves” to add to your dishes. But in terms of the end result, they’re interchangeable.

How to thaw frozen spinach

Wringing liquid out of frozen spinach. Photo / Scott Suchman for The Washington Post; food styling by Lisa Cherkasky for The Washington Post

In the majority of instances, you’re going to need to defrost the spinach before using it. Follow the package instructions for whatever you have, but generally the options are to cook it covered, along with a bit of water, in the microwave (times may vary according to your appliance’s wattage) or on the stovetop. This usually takes less than 10 minutes. Other products can be heated while still in the bag.

Defrosting spinach releases water, and you have a few options to get rid of it. Most of the time I pack it into a dish towel (don’t use one you’re worried about staining), pull up or bundle the edges (so it looks like a wrapped Hershey’s Kiss or a cellophane-wrapped candy), and then twist and squeeze the bundle to wring the water out. (If desired, you can use the greenish water in smoothies, in lieu of broth in soups or stews or, at the very least, for watering plants.) Pressing the spinach in a fine-mesh strainer also works.

Another option: a potato ricer, as reader Jan Arnold of Minneapolis told me via email. “I have been doing this for years, especially for the spinach for lasagna. Easy to control how much pressure you need to obtain the consistency you want.”

But do you always have to thaw frozen spinach? Not necessarily. If I’m just adding it to a soup or stew, I may throw in the whole block straight from the freezer or only partially thaw it in the microwave. Using a frozen block is most doable in a broth, where the spinach will have plenty of time and heat to cook through. Just keep in mind that you may end up diluting the mix because of the water released by the spinach. In that case, start by using slightly less water or broth than the recipe calls for or plan on cooking down the finished dish a bit. And expect the cook time to be somewhat longer.

For food safety, manufacturers typically recommend cooking frozen vegetables, including spinach, to 165 degrees, as they are generally not deemed ready-to-eat. You can do that when you defrost the spinach or once it’s added to a dish. Always read the package instructions for product-specific food safety information.

Can you substitute frozen spinach for fresh?

Don’t use frozen spinach in recipes that call for uncooked fresh spinach, or spinach that’s very briefly cooked. Frozen spinach “has a muddier flavour and a stringier, more fibrous texture, and it lacks the verdant brightness that fresh spinach can add to a dish”, Jessica Rudolph writes at America’s Test Kitchen. You can, however, consider using frozen, defrosted spinach as a substitute in recipes that use the fresh leaves after they’ve been wilted and then cooked longer, or, as Rudolph says, “where there are enough other delicious things going on to distract from the frozen spinach”.

As far as conversion amounts, 1 pound (0.45kg) of fresh spinach will cook down to about 1 1/2 cups cooked, while 10 ounces (0.28kg) of frozen spinach yields 1 cup after cooking and draining, according to The Food Substitutions Bible by David Joachim. Those equivalents are also worth keeping in mind when considering cost, especially if you’re debating going the opposite direction and using fresh instead of frozen.

How to use frozen spinach

Greek Mixed Greens Pie With Phyllo Crust. Photo / Scott Suchman for The Washington Post; food styling by Carolyn Robb for The Washington Post

Given the very small amount of space it takes up, frozen spinach incorporates well into a range of dishes, even those that do not call for it. It mixes seamlessly into casseroles and savoury pies, including lasagna, cottage pie and strata. Use it to add heft and nutrition to sauces for quick pastas or skillet dinners. Sprinkle it over savoury pancakes or tuck into ravioli. And of course, frozen spinach stars in some of the best party dips.