Seltzer’s popularity has been bubbling up for a while. There are a bajillion brands with more on the market every day. Enter the soda maker—a way to ditch the can and make a fizzy drink from the comfort of your home. There are tons of brands out there, but I decided to test a soda maker from a big name in the kitchen appliance realm: Ninja. Its model, aptly called the Thirsti, promises endless customization, including fizz level and flavors. To see if it could live up to its promises, I used it for over a month and made a whole lotta sparkling drinks. 

The Tests

• Carbonation Test: I timed how long the Ninja Thirsti took to make drinks of various sizes and carbonation levels.
• Taste Test: I tried out a few of the flavor pods, tasting each result and noting if the bubbles were pleasantly fizzy and if the flavors were good. 
• Usability Tests: Throughout testing, I noted how easy the Thirsti was to set up, use, and clean.

What We Learned

It Carbonated Fast

I timed how long it took the Thirsti to carbonate drinks ranging from six to 18 ounces, and in short, it's quite fast. When I made a standard 12-fluid-ounce drink with two flavors, it came together in less than a minute. The Ninja also swiftly carbonated 18 ounces of water in under two minutes—impressive.

It Was Easy to Use and Lets You Customize Each Cup

The Ninja Thirsti was easy to set up and use: Twist on the CO2 canister, pop in the flavor pods, and fill up the tank with water. It offers full control over the level of carbonation, bubble size, and flavor potency, so you can fine-tune each cup. (It's worth noting that the smallest drink carbonation setting doesn't let you combine flavors.)

The bubble icon button lets you choose between still, light, classic, or extra fizzy drinks. The serving size options vary depending on the model. The Ninja Thirsti and the Ninja Thirsti Max can make six-, 12-, 18-, and 24-ounce drinks. The difference comes in the largest drink size—the standard bottle makes up to 24 ounces while the Max can make a whole liter.

Whichever model you choose, I liked that it’s simple to toggle between making a cup for myself or a pitcher for the whole family. However, the first couple of times I used it, I accidentally pulled my cup away too early when the machine stopped pouring, only to have it suddenly start dispensing again. Keep in mind there are a few seconds of stalling as it extracts, so wait until you hear the jingle before removing your cup (even if you only selected one flavor).

The Verdict

The Ninja Thirsti is great because it allows for an endless amount of variation, including fizz level and flavors. I really loved the unique flavor combinations. There are currently about 30 flavor pods available, including seltzer, Fruiti Chill, and soda—all with zero calories and zero sugar. The soda flavors taste on par with popular diet sodas. I preferred the unique fruit flavors like pear ginger, dragon fruit, and peach punch. I like that the pods are compact and shut tightly, which makes them easy to store. Although small, each pod can make about twenty 12-ounce drinks. 

The Ninja Thirsti is also really easy to use. The reservoir has an indicator on the bottom that turns bright blue when the water reaches the recommended temperature for carbonating, and it’s also removable, which makes it easy to fill and store in the fridge. You can also minimize splashing by adjusting the tray’s height for smaller cups. It also has indicators to let you know when to replace the CO2 cartridge. It’s a versatile, easy-to-use machine that lets you experiment with making seltzer. 

The Pros

The Ninja Thirsti was easy to set up, customize, and clean. It's compact and slim, so you can tuck it into a corner without taking up too much counter space. I liked the thoughtful design elements like the adjustable cup tray to reduce splashing and an indicator that lets you know once your CO2 canister is running low. My favorite aspect of the Thirsti is its ability to mix and match flavors, so you can come up with something new and refreshing every time. 

The Cons

The biggest downside is that you have to use the proprietary flavor pods. I also would have appreciated flavor pod options that aren't zero-calorie or zero-sugar—as it was, they all were. It also doesn't include a bottle like other soda makers—instead, you have to carbonate each serving as you go.

Key Specs

• Weight: 8.5 pounds
• External dimensions: 13.9 x 8.7 x 16 inches 
• Warranty: One year from date of purchase
• Comes with: A CO2 cartridge and eight flavor drops
• Water reservoir capacity: 48 ounces

FAQs

What’s the difference between the Ninja Thirsti and the Ninja Thirsti Max?

The Ninja Thirsti Max has a larger water reservoir with an ice press built into the lid, and it can make up to a liter of carbonated water at a time. There are also a few design elements, like an adjustable cup tray and an open compartment on top for inserting flavored syrups.

How do you install the CO2 canister?

To insert a can of CO2, open the hidden compartment in the back of the machine and pull the tab out toward you. Then insert and twist the canister until fully tightened. Both models use the same 60-liter CO2 canisters, which produce up to a hundred 12-ounce drinks. The bubble icon on the machine glows orange when the CO2 canister is running low.

Why We’re the Experts

• Octavio Peña is a recipe developer for Serious Eats, Food & Wine, and The Kitchn.
• He’s used soda makers for five years.
• For this review, he used the Ninja Thirsti regularly for over a month.
  

Cooking is chemistry, but too often we overlook one of its most powerful tools: pH. Yet pH is at play in so many of the foods we cook. We use acidic ingredients like tangy yogurt or buttermilk in marinades to tenderize meat, we add a pinch of alkaline baking soda to shrimp to keep them plump and juicy, we add cream of tartar to egg whites so they whip up into a more stable foam, and we squeeze lime juice onto fish to "cook" the flesh without heat. But what about vegetables? Most home cooks are unaware of it, but we can leverage pH to help cook vegetables faster, modulate their texture and appearance, and even improve their flavor.

Let’s break this discussion down into parts, guided by a simple premise: Raising or lowering the pH of a vegetable’s cooking environment (a pot of water, for instance) changes its final characteristics. And we can look at those characteristics from the perspectives of flavor, texture, and appearance.

Flavor

If we are discussing raising or lowering the pH of a vegetable’s cooking environment by adding a basic or acidic ingredient, we need to first acknowledge the impact this will have on the cooked vegetable's final flavor. It’s inevitable that cooking vegetables in an acidic environment will lead to some noticeable sourness, even if minor. And if you’re using acidic ingredients with distinct flavors, such as fruity lemon juice or an assertive apple cider vinegar, the vegetable you're cooking will unavoidably take on that specific flavor, whether lemony or apple-cider-y or something else. The impact on flavor, it's safe to say, will be a major factor for selecting which acid you want to use when cooking vegetables.

On the other end, cooking in an alkaline environment will lead to some level of soapy/chemical flavor—think of the flavor of pancakes with too much baking soda in them. The degree of this off flavor will depend of course on the amount of the alkaline ingredient you use, but also which alkaline ingredient you use. For example, baking soda has a less caustic flavor impact than say ammonium bicarbonate (baker’s ammonia), calcium oxide (quicklime), or lye (sodium hydroxide), which are more concentrated basic ingredients.

Really, the effect on flavor when manipulating a vegetable’s cooking environment is unavoidable. Whether or not it’s a problem really comes down to personal taste and sensitivity to these flavors, and also consideration around how the vegetables are going to be served: If there's a bright vinaigrette for acid-blanched carrots, that tiny hit of acid on the carrots isn't going to matter. As for alkaline ingredients, it's often a balancing act—you’ll need to add enough of the base to get the desired softening effect, but using too much will leave a strong unwanted chemical taste in your mouth.

Texture: It’s All About Pectin

In general, lowering the pH of a vegetable’s cooking environment (that is, making it more acidic) leads to a tougher, hardier exterior, while raising pH (making it more basic) softens or even breaks apart the exterior. Why? It all has to do with pectin, the polysaccharide found in the cell walls of all land plants. Pectin’s primary functions are to facilitate cell adhesion and cell wall hydration, and to control the degree of cell wall porosity. If cellulose molecules are the bricks of a plant cell wall, then pectin is the cement (or glue) that holds those bricks together.

Pectin is sensitive to changes in pH. In an alkaline, high-pH cooking environment (say, greater than 8.0), pectin breaks down and dissolves more quickly, leading to mushier, softer textures as the cell walls fall apart more readily. In an acidic, low-pH cooking environment (around 6.0 or lower), that rate of breakdown slows dramatically, so vegetables retain more of their shape, crispness, and even crunch throughout the cooking process.

Understanding the effects of pH on a vegetable's texture can lead to powerful results in the kitchen. Let's look at some specific examples.

Some of the best examples of pH at work come from cooking potatoes. Take Kenji’s extra-crunchy potato chips recipe, where a sneaky addition of vinegar to the cooking water helps the potatoes retain their shape and firmness. Conversely, in Kenji’s crispy roast potatoes recipe, raising the pH of the cooking water with baking soda helps the exteriors of the potatoes break down more, creating a starchy slurry that leads to an extra-crisp coating encapsulating a fluffy interior.

How does changing pH affect the texture of other vegetables? For example, soaking and cooking dried beans in a solution of baking soda is common practice. The baking soda raises pH and displaces calcium in pectin (more on that later), softening the tough pectin shell.

What about vegetables like broccoli or green beans, or even carrots? We’d expect similar results: Tougher, more toothsome textures at lower pH values, and softer, more broken down textures at higher pH values. I set up some simple tests to verify this idea.

I cooked vegetables in three different solutions of 5-percent saltwater for 10 minutes each: a low-pH solution mixed with distilled white vinegar, a high-pH solution mixed with baking soda, and a neutral ‘control’ solution with nothing added. Here’s what happened.

Potatoes

There’s a notable difference in textures here. On the left, the low-pH samples showed virtually no deformation, and were almost crunchy when I bit into them. The control was what you’d expect of boiled potatoes: slightly broken down, a little fuzzy at the edges. But as pH rose above neutral, the exterior appeared fuzzier and fluffier, and the potatoes broke or mashed apart at the slightest manipulation. In informal cooking terms, these taters were “hammered.” 

Carrots

Once again, we see similar results to potatoes. Low-pH carrots looked pretty much raw—and ate that way. As pH increased above neutral, the carrots became much softer. The exteriors developed a fuzzy, brittle appearance. I could even mash the samples between my fingers. These carrots ate almost like baby food, requiring little to no chewing before they turned to mush. In other words, they’d be perfect for a smooth puree or sauce. 

Onions

The low-pH samples looked pristine—just barely cooked, with a noticeable snap when I bit into them. The neutral onions were softer, but still held their shape. On the extreme end, the high-pH onions were complete mush, devoid of any structure, and almost silky or jam-like in texture.

Key Takeaways for How pH Effects Vegetable Texture

• Lowering the pH of a cooking solution with an acid tends to yield more toothsome vegetables that retain their shape throughout the cooking process; they also break down less readily.
• Raising the pH of a cooking solution with a base tends to result in softer, mushier vegetables with less structure; they break down more readily.

Appearance: Colors Matter

If pH has such an outsized effect on the texture of cooked vegetables, it shouldn’t surprise us that it can change their appearance too. Take green vegetables like spinach or kale, for example. These vegetables are rich in chlorophyll, the pigment that gives plants and algae their green hue. In isolation, even in room temperature water, chlorophyll is sensitive to changes in pH: in the pH range of 2-5, it turns from green to olive green, even yellow; in the pH range of 6-13, chlorophyll stays vibrant green. That's at room temperature, so it's important to keep in mind that these results shift slightly when heat is introduced.

Chlorophyll isn’t the only pigment affected by pH. Take anthocyanins, for instance, the purple-red pigments found in red cabbage, red onions, and blueberries. In acidic conditions, anthocyanin turns a stark crimson red; in basic solutions, it turns violet to blue. In fact, red cabbage juice can often be used as a “quick and dirty” pH indicator for solutions because of how dramatically and reliably its color shifts in different pH environments.

Once again, I set up three different 5-percent saltwater solutions of varying pH ranges to cook the vegetables, and kept my eye on their color.

Broccoli

As expected, there were dramatic changes in color depending on the pH of the cooking solution. In a more acidic solution, broccoli turned an olive green, almost yellow. At neutral, the florets stayed green, but the stems took on a paler green. In a basic solution, the florets turned a vibrant green, and even the stems turned much greener than the neutral samples. 

Leek Tops

For the most part, I had similar results with leek tops. At low pH, the leeks were a dull gray-green, lime green at neutral, and deep vibrant green at high pH.

Snap Peas

Same story for snap peas. Note that even when cooked at higher pH, snap peas retained some of their crunch and did not turn mushy, a sign that their name is apt—they really do hold onto that snap. 

Red Cabbage

You can observe the striking difference in color. Note that at higher pH, there is a gradient from blue to purple at the interior, indicating incomplete penetration of the cooking solution over a 5-minute period. 

While these results are specific for a blanching/boiling environment, it's worth mentioning that in a baking/roasting environment, it’s likely there would also be enhanced Maillard reaction in an alkaline environment as well.

Key Takeaways for How pH Effects Vegetable Appearance

• As the pH of a cooking environment falls below 7.0 (more acidic):
• Green vegetables become olive green or even yellow.
• Anthocyanin-rich vegetables get redder.
• As the pH of a cooking environment rises above 7.0 (more basic):
• Green vegetables stay more green and vibrant.
• Anthocyanin-rich vegetables become violet or unnaturally blue.

Practical Tips: The Easiest Ways to Adjust pH

Ok, we’ve firmly established that pH matters when cooking vegetables. But how do we adjust pH in a practical way?

Lowering pH

The simplest way to lower the pH of water is to add an acid. You’ve got several options, but here are just a few:

Lemon Juice 

Chances are you’ve got a lemon or two hanging out in your fridge. And for centuries, cooks have relied on lemon juice for an instant shot of acidity. The downside? In order to lower the pH of say, a large pot of water, you might need to use a substantial amount of lemon juice. And depending on the recipe, that citrus flavor might come through in the finished product. 

Vinegar

If you don’t want that bright citrus flavor of lemon, then vinegar—any type will work, but especially distilled white vinegar—is a great alternative. Its acidity is roughly on par with lemon juice. Of course, you could opt for other vinegars like apple cider or rice wine vinegar, but I wouldn’t break out the fancy Banyuls or aged balsamic for this application.

Citric Acid Powder

Though it’s less common in the average pantry, citric acid powder might be one of the best ways to lower the pH of a solution. You can easily measure it to the gram, you don’t have to use too much in order to lower pH enough for the desired effect, and its flavor (other than sourness) is arguably less distinctive than lemon juice or most vinegars. 

Raising pH

There are multiple ways to raise the pH of a cooking solution to make it more alkaline.

Baking soda

Baking soda is, by far, the most common alkaline ingredient available in the average kitchen. It’s a mild alkali, which means it is relatively weak and safe to use in reasonable amounts compared to other pH-raising additives. And when it comes to vegetable cooking, in addition to raising pH of blanching water, baking soda does double duty: It further breaks down pectin by adding sodium to the water. Through a process known as a displacement reaction, sodium displaces calcium in pectin, weakening a vegetable’s cell structure. 

At first thought, using baking soda and ending up with mushy broccoli might seem like less favorable results. But using baking soda to raise the pH of a cooking environment can actually be very useful: You can shorten cooking times via the softening power of baking soda, retaining a brighter, less cooked flavor while still getting a cooked texture, and also locking in that bright green color. This is a major win for vibrant vegetable soups like my broccoli soup recipe, or sauces like in Sasha Marx’s creamy orecchiette recipe, or even the most basic of vegetable purees. 

Other alkali sources

Other, less common alkaline additives include a roster of food-safe alkali salts: sodium carbonate, potassium carbonate, potassium bicarbonate, ammonium bicarbonate (baker’s ammonia), calcium oxide (quicklime), and even sodium hydroxide (lye). 

Many of these additives are stronger than baking soda, sometimes caustic, and often have a pronounced bitter or soapy taste when used without discretion. So why use them at all? Well, sometimes you might need to raise the pH of a cooking environment far higher than baking soda might be able to (without using a concerning amount) such as when making Bavarian-style pretzels or alkaline noodles such as ramen noodles.

The Bottom Line

Here’s a quick-and-dirty breakdown of trends as pH increases or decreases for blanching vegetables.

As pH Falls Below 7.0 (more acidic):

• Vegetables tend to stay more toothsome or crisp, and retain their shape through cooking; it takes longer to cook them until tender.
• Green vegetables take on a dull green or pale yellow color.
• Anthocyanin-rich vegetables turn pink or crimson.

As pH Rises Above 7.0 (more basic):

• Vegetables tend to get softer and mushier, which may be ideal for mashes, purees, or sauces.
• Green vegetables become vibrant green.
• Anthocyanin-rich vegetables turn blue to violet.

In my Indian home state of Maharashtra, a favorite traditional savory breakfast is pohé: parched, flattened rice (which is also called poha in other parts of the country) paired with onions, a medley of spices, and vegetables such as potatoes, green peas, cauliflower, or tomatoes. While a breakfast mainstay, pohé is also often served at teatime, enjoyed with a hot cup of chaha (chai). It was my preferred Sunday breakfast as a child and now as an adult, an easy and satisfying meal I routinely cook at home on busy weekday mornings, or even for a simple light dinner.

I first learned how to cook pohé from my mom. Her version was bright yellow from a generous amount of turmeric and heavily spiced with cumin and mustard seeds,a combination of spices she used in many of the savory Indian dishes she made. But honestly, her version was never my favorite. The version I like best I learned from my father’s family, who come from the city of Pune.

It wasn’t until I was living in California that I learned how to cook their version during a visit from my father’s cousin Shirish Marathe and his wife Sushama; my recipe below is based on theirs. It’s faint yellow from a reserved amount of turmeric (less than my mom’s), with a subtle sweet-and-savory kick. In my opinion, it’s the absolute best way to prepare pohé.

How to Make Pohé

Pohé (the ingredient) is de-husked rice that’s been soaked in hot water, dried, and then pounded into flat flakes; at this point they are a preserved food with a long shelf life. Since it’s basically rice that’s been par-cooked and treated, it cooks much faster than raw rice does; it really only needs to be briefly rehydrated and heated through before eating.

The best way to do this is by soaking the grains in a small amount of cold water for just 15 minutes. Cold water works best, as soaking it in hot water runs the risk of overcooking the par-cooked grains. It’s also important to stir occasionally during this time to ensure the grains hydrate evenly.

To build the seasoning-base for this recipe, I use the same mustard seed, turmeric, and asafetida seasoning that my father's cousin’s wife Sushama used in her version. In the Indian state of Maharashtra, where my family is from, asafoetida-mustard-turmeric is often considered the “holy trinity” of seasonings.

Asafoetida is a gum resin that drips off the roots of an herb called ferula asafoetida, a Central Asian plant in the celery family. It is gathered and then ground into a powder. Nuggets of it used to be left in sacks of grain because bugs stayed away from its strong aroma. Cooks in India learned that its sulfurous, onion-garlic smell and flavor was a welcome addition in many dishes. My father didn't like asafoetida’s pungent aroma, so my mother never cooked with it when I was growing up. But as an adult I’ve grown to love its flavor and always use it when I make a mustard-seed seasoning, like I do here in this pohé recipe.

The spices are bloomed in hot oil—and I mean ripping hot, those mustard seeds should pop like popcorn on contact with the pan—before fresh green chiles, curry leaves, and onions are added. It’s important that the onions are cooked only briefly so they still retain a bit of their crunch, which creates a nice contrast to the tender rice in the dish. At this point, the vegetables—your choice of potatoes, green peas, cauliflower, or tomatoes—are added and steamed in the covered pot until just tender.

The soaked rice is then stirred in and everything is briefly cooked until just warmed through. Since the rice is already softened from soaking, you’re really just warming it through and coating it evenly in the spice mixture. Just before serving, I like to add a small amount of sugar and lime juice to balance the pungent and savory spice blend.The final dish should be salty, tart, faintly sweet, and pungent all at once, and you might need to adjust with more salt, lime juice, or sugar to find the right balance.

Beyond my listed serving suggestions of a sprinkle of cilantro, grated coconut, and a side of plain yogurt, I also recommend serving pohé with a variety of condiments such as cilantro chutney, tomato–curry leaf chutney, or quick mango pickle.

Every time I prepare pohé this way, I feel deeply connected to my aunt and my family, and am grateful to them for learning how to prepare this incredibly flavorful dish.

In a medium bowl, add pohé and cover with cold water. Gently swish with your hand, then drain through a fine-mesh strainer. Shake well to remove any lingering water, then return pohé to the empty bowl. Let sit, gently stirring pohé occasionally with a metal fork to separate grains and prevent clumping and being careful not to break grains, until grains are soft enough that, when a grain is pressed gently between thumb and forefinger, it breaks, about 15 minutes. If pohé is too dry, sprinkle 1 tablespoon of water over top and mix in gently, then rest pohé about 5 minutes longer before checking texture again. Once softened, gently stir in in 1/4 teaspoon turmeric, 1 teaspoon salt, and 1/2 teaspoon sugar.

While pohé rests, in a 6-quart saucepan, heat oil over medium-high heat until just smoking, about 1 minute. Keep a lid/screen handy. Reduce heat to low and test the oil with one mustard seed. If it pops right away, the oil is ready; if not, return heat to medium-high for 1 additional minute and retest. When ready, quickly add the remaining mustard seeds to the saucepan and cover with the lid/screen. The mustard seeds will pop, making a sound like popping corn until the popping stops, about 20 seconds. Immediately uncover pan, reduce heat to low, and quickly stir in remaining 1/4 teaspoon turmeric, asafetida, and green chiles to oil. Increase heat to medium and immediately add onion and curry leaves, if using, and cook until onion is softened, about 1 minute.

Stir in the vegetable of your choice and increase heat to medium–high. Stir in 1 teaspoon salt and 1/2 teaspoon sugar. Cover pot, reduce heat to medium, and cook, stirring occasionally, until vegetables are tender (or potatoes: 10 to 12 minutes; for cauliflower: 7 to 8 minutes; for green peas and tomatoes: 2 to 3 minutes).

Gently stir in softened pohé, then cover and cook, stirring once or twice, until grains are heated through and everything is tinged in yellow, 4 to 6 minutes. Remove from heat.

Stir in lime juice and cilantro. Season to taste with salt, lime juice, and/or sugar, if needed. . Transfer to serving bowls, sprinkling pohé with cilantro and coconut, if using. Serve with plain yogurt on the side, if desired.

Special Equipment

Fine-mesh strainer, 6–quart saucepan with lid or splatter screen

Notes

Pohé can be purchased at South Asian grocers. Make sure to buy thick pohé (poha) so that when it is rehydrated, it does not disintegrate. Do not use hot water to rinse and rehydrate the pohé, as that will also make it fall apart.

Asafetida can be found at most Indian grocers. It’s also available to purchase online. I recommend the powder sold in small jars, rather than large plastic containers, because they absorb the aroma. You will smell an onion-garlic aroma from the asafoetida when you open the container. Keep it tightly shut between uses, otherwise the smell will pervade your entire kitchen. While it adds a distinctly assertive garlic-and-onion flavor to the pohé, you can omit it if unavailable, though the result will be less aromatic.

Do not use a nonstick pan or a plastic or wooden stirrer when making pohé. The nonstick pan is has a dark interior that makes it difficult to see the spices when cooking, increasing the risk of scorching them, while plastic or wooden spoons are more likely to break the pohé or make it clump up.

Make-Ahead and Storage

Pohé can be refrigerated in an airtight container for up to 1 day. To reheat, microwave pohé with 1 added tablespoon of water in a bowl, covered, until hot.