How to Make Tomato Sauce Less Acidic
Sugar, baking soda, cream, or butter. Which ingredient works best to tone down acidity in overly tart tomato sauce?
There’s nothing quite like a perfect ripe tomato. As many as 400 compounds come together to form the flavors and aromas we recognize as tomato-y, allowing it to taste sweet, tart, savory, and a little bitter all at once.
But peak tomato ripeness is elusive, and the flavors on either side of it tend to swing noticeably acidic as the fruit’s sugar content is still ramping up or beginning to drop off if left on the vine too long. It’s not always so noticeable when you’re piling sliced tomatoes on BLTs or dressing them in a salad, but you can really taste the tartness when you cook down a big pot of them for pasta or pizza sauce.
Luckily, there are numerous ways to tone down that sharpness. We tested two of the easiest and most common approaches (adding sugar or baking soda) to see if we liked one better than the other.
But before we get to those results, let’s take a closer look at tomato flavor and how some tomatoes wind up tasting more tart than others.
WHAT MAKES TOMATOES TASTE OVERLY ACIDIC?
Fresh ripe tomatoes contain from 0.3 to 0.6 percent acid: primarily citric, malic, and ascorbic acid. While tomatoes can have more or less of these acids, most varieties (even those that are purportedly low acid) generally fall within the same relatively narrow range.
Another important factor in determining how tart a tomato tastes is its overall balance of flavors and aromas, particularly sweetness.
While some tomatoes have been bred to have more glucose and fructose, generally, the riper the tomato (up to a point) the sweeter it will taste, due to the development of sugar during the ripening process.
By the same token, underripe tomatoes taste more tart since they lack some of the sweetness that would otherwise offset their acidity. (And after a tomato is past its prime of ripeness, its sugar level drops.)
The lesson: For a tomato sauce that tastes less acidic from the get-go, use only ripe tomatoes from your backyard or the farmer’s market, or a canned brand that doesn’t include added citric acid, which can increase tartness. (Our favorite canned tomato, Cento San Marzano Certified Peeled Tomatoes, has no added citric acid and produced a sauce tasters described as “bright, fresh, and sweet.”)
TESTING SUGAR VS. BAKING SODA: WHICH DOES A BETTER JOB OF TONING DOWN TARTNESS?
To determine whether adding sugar or baking soda is more effective in reducing acidity in tomato sauce, we made a giant batch of our Quick Tomato Sauce, divided it into 3-cup samples, spiked some with either sugar or baking soda, and then tasted each side by side.
Both ingredients altered the tart taste of the sauce. But the sample enhanced with just ¼ teaspoon of sugar tasted bright, balanced, and more intense in tomato flavor, while the sample with an equal amount of baking soda was deemed a little flat in comparison, with a more one-dimensional sweetness, even when we scaled down the amount to ⅛ teaspoon.
WHY BAKING SODA CAN DULL TOMATO FLAVOR
Even a small amount of baking soda significantly raises the pH of the sauce. While this reduces acidic taste, it also tamps down on the brightness that gives the tomato complexity. (Analogy: If you have lemonade that's a little too tart, you could add sugar, masking the tartness with more sweetness, and leaving it full of flavor; or you could add water, which makes it less tart at the expense of flavor.)
For this reason, it’s not our favorite way to reduce acidity in tomato sauce.
HOW TO TAME OVERLY ACIDIC TOMATO SAUCE WITH SUGAR
For every 3 cups of tomato sauce, add ¼ teaspoon of sugar at a time until the desired flavor is reached.
Why the approach works: Though the sugar will not actually neutralize acidity, it changes our perception of other tastes, mellowing tartness while maintaining the sauce’s complexity.
OTHER WAYS TO TAME TARTNESS IN TOMATO SAUCE: ADD CREAM OR BUTTER
Cream and butter will also tone down acidity in tomato sauce, but like baking soda, they can have downsides.
CREAM: Cream can temper the acidic taste of tomato sauce in two ways: Its proteins (particularly casein) will bind with some of the acid molecules from the tomatoes, reducing their concentration. At the same time, its fat coats the tongue, physically blocking some of the flavor molecules, including those of acid, from reaching taste receptors. But cream can alter the consistency of the sauce and mute overall flavor. It’s best to start conservatively, adding 1 tablespoon of cream at a time.
BUTTER: Butter works in the same way as cream, its proteins binding with some of the acid molecules (although it contains less casein than cream does) to reduce their concentration. More importantly, its fat also coats the tongue, blocking taste receptors. Also like cream, too much can mute flavor. Start with 1 tablespoon at a time.
