Part 10: Communicating How to Use Vinegar Effectively — Iwama Akiko, Who is Enthralled with Vinegar, Recommends Adding a Little Vinegar To Your Meals

In this ongoing series, we ask food professionals for their top recommended fermented foods. Our guest for Part 10 is Iwama Akiko, a vinegar researcher and fermented food expert. Besides developing recipes that feature vinegar and holding cooking classes, she travels around the country visiting vinegar breweries, and even attends university laboratories to study vinegar. Her love for and curiosity about vinegar knows no bounds. Vinegar is also known for its potential health benefits. Let’s delve into the multifaceted attractions of vinegar together with Iwama.

Fascination with vinegar led her to become a vinegar researcher and fermented food expert

A qualified dental hygienist, Iwama Akiko is a business professional who works for a dental material producer. Her pursuit of a career in cooking was motivated in part by a frustrating experience she had just after getting married.

“In the months after we got married, the only thing I made that my husband would praise me for was namasu [a dish of thinly sliced uncooked vegetables and seafood, marinated in rice vinegar]. He said that he could eat my namasu every day, but he had a rather harsh response to anything else I cooked. (laughs) Out of frustration, I started studying cooking on my own, and then the turning point came when I became an instructor at Yummy’s Cooking Studio. When a friend asked me what my favorite seasoning was, I realized that I truly liked vinegar. I was taught about vinegar culture and vinegar uses around the world, and I gradually became more and more absorbed with the world of cooking and vinegar.”

Looking back today, she realizes that she has always favored sour foods. For example, her favorite as a child was sasazuke pickled sea bream. Moreover, she used vinegar more than any other seasoning at home.

“Once I became aware of how much I loved vinegar, it was like a lightbulb going off in my head. I traveled to places up and down the country in search of delicious vinegars, thought up vinegar recipes, and learned how vinegar is brewed. During this time, my interest in all aspects of fermented foods grew, and I started making miso and salted koji [rice malt] by hand.”

Delicious vinegar is produced by time and the hard work of acetic acid bacteria

A sample of vinegars that Iwama loves to use. “Many vinegars from regional breweries can only be purchased locally. If you spot an unusual vinegar at a brewery, regional supermarket, or highway service area, be sure to pick it up.”

“Saké is the basis of vinegar. The acetic acid bacteria feed on the alcohol in the saké and metabolize it to produce vinegar. So wherever you find saké being made, you’ll also find vinegar. Vinegar cultures exist in all parts of the world. In Europe, you have wine vinegar and apple vinegar; in China, black vinegar that uses glutinous rice saké as its prime ingredient; and in Thailand, coconut vinegar. But no country rivals Japan in the range of vinegars produced, such as rice vinegar, wine vinegar, and various fruit vinegars.”

Iwama has made it her life’s work to visit breweries around the country and share the stories of unique regional vinegars and vinegar-making traditions.

“The appeal of vinegar is that it is made using ingredients local to that region. For example, irregularly-shaped fruit and split rice are turned into delicious vinegar. You could say that vinegar is a food that contributes to the SDGs. Vinegars from small breweries don’t reach the major distribution systems and are only enjoyed in the local area. When I travel, I find it interesting to look for local vinegars.”

After being bottled, vinegar undergoes heat sterilization, which kills the acetic acid bacteria in the vinegar. However, the effect of the acetic acid produced by the acetic acid bacteria does not change. Furthermore, it is said that the longer the vinegar is aged, the mellower the taste becomes.

“Matured vinegar is mellow without any pungent smell. Its color also becomes deeper as it matures. Some vinegars are matured in barrels for three to five years before being bottled. When selecting a vinegar, it’s a good idea to check how long it was aged.”

The power of vinegar and the many health benefits from just a tablespoon a day

Adding fruit vinegar or wine vinegar to tea gives it a refreshing flavor like that of lemon tea. “The blood circulation benefits of vinegar will warm you up from your insides.”

Her interest in vinegar is insatiable. Besides being a company employee and cooking expert, Iwama is a research student. In 2023, she began commuting to the Tokyo University of Agriculture once a week as a research student at the Laboratory of Seasoning Food Science. Many new data and papers have come out, reporting on the behavior of acetic acid bacteria and the effects of vinegar.

“We know that vinegar has many benefits. The health benefits of vinegar, in particular, are gaining lots of attention today. I’m sure many people have experienced the fatigue recovery and appetite stimulation effects of vinegar. The main component of vinegar, acetic acid, has many other beneficial effects on the body, such as suppressing fat absorption, lowering blood pressure, and improving blood circulation. Recent research has reported such effects as improving skin condition (black vinegar, balsamic vinegar), boosting immune functions, and preventing hangovers (vinegar containing acetic acid bacteria).”

Ordinary vinegar is a clear liquid because it is filtered after brewing. Recently, unfiltered vinegars have appeared that contain their original acetic acid bacteria. “There are vinegars that have sediment at the bottom, like some wines, or are cloudy, indicating that they retain their acetic acid bacteria. Some products are marked as containing acetic acid bacteria.”

The key to getting the health benefits of vinegar is to make a habit of having a tablespoon of vinegar every day.

“Although there are many kinds of vinegar — rice vinegars, fruit vinegars, wine vinegars — they all share the same health benefits. Even though the ingredients may differ, the fermentation process, driven by the power of acetic acid bacteria, is the same. And with apple vinegar, for instance, you gain the nutrition of apples along with the benefits of acetic acid, while persimmon vinegar includes the nutritional composition of persimmons. When selecting a vinegar, the key is the ingredient list. I recommend simple vinegars, such as those made from just rice, just apples, or just grapes. The acidity level is a good guide to the strength of the vinegar’s sourness. Most vinegars have an acidity level of between four and seven percent. It’s also good to use different vinegars for different meals.”

Recommending the use of a little table vinegar

One of Iwama’s research topics is so-called table vinegar. The hypothesis is that if vinegar becomes an established seasoning placed on dinner tables, much like soy sauce bottles, then vinegar will become more familiar to people. Her research is ongoing into plain-tasting vinegar that suits a broad range of food ingredients and cooking methods.

“I was thinking about how people can get vinegar into their diet every day without going out of their way. The proposal I came up with was table vinegar, which is something I really want to see take off. If people can enjoy tailoring the taste of their food with vinegar while also getting its health benefits, it’s a win-win situation.”

Tomatoes and vinegar go particularly well together in dishes such as spaghetti Napolitan [a ketchup-based pasta unique to Japan] and meat sauce pasta. “My top recommendation is Haliyo’s mature unpasteurized persimmon vinegar. The eye-dropper style of bottle is a cute design and it fits right in as a table vinegar.”

“Vinegar goes well with Italian dishes as well as Chinese-influenced dishes like ramen, stir-fried noodles in a thick starchy sauce, prawns in chili sauce, and mapo tofu. The interplay of different sour tastes creates a synergistic effect of umami flavors, so even just a dash of vinegar on your spaghetti Napolitan, for example, will deepen its umami. I also recommend using vinegar on days when you’re having frozen foods or prepared dishes. And I recommend it with grilled fish. Sprinkle a little salt on the fish and grill it until it’s crisp, and then serve it with vinegar. The vinegar will coax out the fish’s natural umami, making the dish taste exquisite. And adding vinegar will allow you to reduce your salt intake.”

Vinegar plays a big role in cooking in Iwama’s household. For her, vinegar is especially indispensable when making meals and dishes ahead of time.

“Vinegar has a powerful sterilizing effect, so it helps food keep fresh for longer. For dishes like kinpira [sautéed and simmered root vegetables] and nimono [simmered dishes], you can add vinegar with other seasonings like soy sauce, saké, and sweet koji, and then heat the dish. Once the dish has been heated, you will barely notice the vinegar’s sourness. Another benefit is that vinegar helps eliminate meat and fish odors. When preparing fish or kneading hamburger meat, add about a teaspoon of vinegar per 200 grams of minced meat. Vinegar immediately upgrades bargain-priced meat.”

Acetic acid is very heat resistant, so it remains effective even after being boiled.

“The effectiveness of acetic acid is reduced by half at 118C, so it poses no problems when simmering or grilling a dish. In addition to dishes where you like a bit of sourness, I recommend sneaking in a small amount of vinegar when preparing ingredients and to keep dishes longer.”

A recipe for vinegar apple pie served with ice cream

The uses of vinegar are endless. It works well when baking pastries. So how about a fancy apple pie made with apple compote using vinegar?

You can substitute an equal amount of amazake [a sweet drink made from fermented koji] or sweet koji for the hon mirin. “The fermentation’s complex umami flavors blend together to create a compote with a gentle sweetness.”

“Another quality of vinegar is it keeps food looking nice, preventing food from turning brown. People often use lemon juice in compote, but the combination of apple and apple vinegar were made for each other. The apple’s sweetness is brought out by just the right amount of acidity. You can add warm water to the compote and have it as a refreshing drink, or put it on yogurt for a delicious treat.”

Serve the freshly baked apple pie with cold ice cream. Iwama’s style is to sprinkle some vinegar on the ice cream too.

“The vinegar transforms affordable ice cream into the flavor of a premium brand. Vinegar is thought to suppress the body’s absorption of fat, so you can have it guilt-free. (laughs)”

In our next installment, Kaneko Fumie, a cooking specialist, will be taking the baton from Iwama. We will hear from Kaneko about her homemade temae miso that she makes without fail every year. Be sure not to miss it.