How to make your own kashk, a creamy, tangy staple of Iranian cuisine

Naz Deravian

THE WASHINGTON POST – When my family settled in Vancouver in the early 1980s, what we lacked in furnishings we more than made up for with a freezer packed with party-size plastic tubs of ice cream and an overflowing fridge of gallon jugs of milk.

At first glance you might mistake us for a milk-drinking obsessed family, which couldn’t be further from the truth. What we were passionate about, however, was the magical transformation of the milk into two equally magical products.

One that soothed our homesick hearts: yogurt. And another that indulged our taste buds; sustained us economically in our newly adopted home; and ultimately filled those ice-cream tubs (once the contents were happily consumed, in large part thanks to me): kashk.

Like so many immigrants before her, my mother, a university professor and poet by trade, turned to food to provide for the family. She set out to supply the lone Iranian market in the city at the time with various Iranian goods, including homemade kashk, packed and delivered in repurposed ice cream buckets. As we got closer to Nowruz, Iranian New Year, she also made sure to set aside a bowl of kashk for our pot of aash-e reshteh – the hearty, herb-based, bean and noodle soup served around the new year celebrations.

Iranian kashk is a rich, creamy, sour, sometimes salty, nutritious and deeply flavourful dairy product. Think of it as a more assertive and soulful cousin of thick yogurt or sour cream. Its fermented acidic notes appeal to the sour-leaning Iranian palate, and add depth and body to an assortment of dishes. Kashk, in varying preparations and names, is also used in several neighbouring countries and regions, such as Afghanistan, the Caucasus, Iraq, Lebanon, Turkey and Palestine.

To understand Iranian kashk is to appreciate the centuries-old art of preservation in Iranian cuisine.

Kashk-o Bademjan (Eggplant Dip With Kashk). PHOTOS: THE WASHINGTON POST
Liquid Kashk With Yogurt

Before the days of refrigeration, and even today, shepherds throughout Iran have had to efficiently make use of the abundance of the fresh milk they produce. In an effort to keep the milk from spoiling, it is put through a series of transformations and fermentations.

The cycle that eventually leads to kashk begins with the milk being cooked, cultured and transformed into yogurt.

The yogurt is then churned. In this process, the fat separates and turns into butter, and the liquid that is left over is called doogh.

Iranian kashk is traditionally made with the doogh left over from making yogurt butter. These days, the word doogh is commonly associated with the popular mixed drink of yogurt, water, salt and mint.

In English, the words buttermilk or whey are used to define this liquid. (The buttermilk that is available in our grocery stores is the liquid left over from churning cream into butter, and is not used for making kashk.)

Doogh is naturally fat-free, since the fat has separated, and boasts plenty of nutrients, such as calcium and protein. There are varying preparations of kashk. Traditionally, in Iranian villages, the doogh is placed in large sacks and set out to strain for a long period of time. More typically, the doogh is cooked with some salt until it splits and curds rise to the top. It is then strained in a sack, and the creamy ingredient left over in the sack is called kashk.

To preserve kashk, it is left to strain and pressed to remove all the moisture. It is then formed into round or oval balls and left out to completely dry and ferment. The dried balls are then reconstituted with water, turned into a creamy liquid and used.

To complete the cycle, the liquid remaining from straining kashk is further cooked, reduced, thickened with wheat starch, and turned into a very tangy and potent paste called ghara ghoroot (black kashk). Not a single drop of milk wasted.

These days, with the availability of refrigeration, it is more convenient to use jarred liquid kashk, rather than reconstituting dried kashk. Preparing homemade Iranian liquid kashk is quite simple; it just takes time and a little patience – something we’ve all had to have more of this past year.

Natural doogh is not easily attainable outside of Iran, but you can still produce an incredibly tasty liquid kashk at home by combining soured yogurt, water and salt to taste. This mixture is cooked similarly to the doogh preparation and then strained in a sack or cheesecloth for a couple of minutes. The kashk is then blended with a little water, if necessary, for a smooth and creamy consistency and stored in a jar in the fridge or freezer. Homemade kashk is much closer in taste and texture to that of kashk prepared the traditional way with doogh in Iran.

If making homemade kashk is not an option, store-bought jarred liquid kashk, often labelled as whey, is readily available at Iranian markets and online. Keep in mind, store-bought kashk is saltier than homemade.

Kashk can be stirred in as a final ingredient, or dolloped on as a garnish, to enrich and add tang, creaminess and depth of flavour to a variety of dishes (such as soups, dips or roasted vegetables). Use it just as you would yogurt or sour cream. If your jarred kashk is too thick, you can thin it out with water. Like yogurt, kashk can also split when heated and shouldn’t be boiled or cooked too long.

Aash-e reshteh gets its final kick of flavour from kashk. As does the beloved Iranian eggplant dish – kashk-o bademjan – which means kashk and eggplant. Despite its humble name, kashk-o bademjan bursts with complex flavours. Although not traditional, it has found a permanent place at my Nowruz table. I like to serve kashk-o bademjan as an appetiser before we settle in for our Nowruz meal of sabzi polo, mahi and kookoo sabzi.

This Nowruz, I won’t be filling ice cream buckets with kashk. But, like my mother almost 40 years ago, I will stand sentinel and determined next to the pot of yogurt simmering away on the stove, and try my best to navigate a new world facing unforeseen challenges. Then I’ll fill a jar with fresh kashk – just enough to stir into our aash-e reshteh and kashk-o bademjan, and welcome a new year – with hopes for brighter days ahead.

LIQUID KASHK WITH YOGURT

Active time: 15 minutes; Total time: Up to 2 hours, 45 minutes

24 servings; two tablespoons per serving; makes about one and a half cups

Traditionally in Iran, the yogurt for making kashk is left at room temperature for two days to sour. Another method is to decant the yogurt into a bowl, place a stainless steel spoon in it, and leave it at room temperature for two hours. You can use refrigerated yogurt, but the kashk might not get as tangy.

To properly strain the kashk, you will need a mesh strainer and a nut milk bag or several layers of cheesecloth. A nut milk bag made of nylon or similar heavier fabric is preferable. To measure the water, simply fill the empty yogurt container with water.

Storage Notes: Kashk can be refrigerated in an airtight container for up to one week or frozen for up to three months.

INGREDIENTS

One container plain sour yogurt

Four cups cold water

One tablespoon kosher salt

DIRECTIONS

In the pitcher of a blender, combine the yogurt, water and salt and blend until smooth and the salt dissolves, about one minute.

Transfer the mixture to a medium pot set over high heat and bring to a boil, stirring constantly so the mixture doesn’t overflow. Reduce the heat to medium-low and simmer for two hours to two hours 30 minutes, stirring occasionally and making sure nothing sticks to the bottom of the pot. The yogurt will separate, break down and develop a distinct tart smell, and you will start to see curdled pieces of yogurt rise to the top – that’s what you want.

Eventually, most of the water will evaporate, leaving a thick batch of curds in the pot. The colour can range from a creamy white to a pale beige. Remove the pot from the heat and cool for five minutes.

Place a fine-mesh strainer over a large bowl. Prepare a nut milk bag or several layers of tightly woven cheesecloth and line the sieve with it. Very carefully, ladle out the contents of the pot (the liquid and the curds) into the nut milk bag or cheesecloth. Let strain for one minute; what is left in the bag or cheesecloth is kashk. Save the liquid to thin out the kashk, if necessary.

Return the kashk to the blender and process until smooth. If necessary to achieve the desired consistency, drizzle in the saved liquid, a few drops at a time (you can use fresh cold water if you prefer). Taste, and season with more salt, if needed. The kashk should have the consistency of strained yogurt. Transfer the kashk to a small container until cool to the touch, cover and refrigerate until needed.

KASHK-O BADEMJAN (EGGPLANT DIP WITH KASHK)

One hour

Six to eight servings as an appetiser

Kashk-o bademjan is a beloved Iranian dip that seduces even the most ardent eggplant skeptics. Firm Japanese or Chinese eggplants are used here because they have fewer seeds and are less bitter. You can either fry or roast the eggplant; the version below relies on roasting. (See VARIATION for frying instructions.) Keep the tops of the eggplant on while roasting to prevent them from drying out. The garnishes are as essential to the dish as the main ingredient, so don’t skip them. Please note that fresh mint cannot be substituted for dried mint for the na’na dagh.

Serve kashk-o bademjan with a flatbread, such as sangak or lavash, for dipping and eat it as an appetiser, or a light lunch or dinner.

Make your own kashk or buy it. Keep in mind that jarred kashk is saltier than homemade, so hold off on extra salt until after you’ve added the kashk. You can substitute Greek yogurt or sour cream for the kashk and adjust seasoning accordingly.

Make Ahead: The piaz dagh, seer dagh and na’an dagh can be refrigerated for up to one week or wrapped tightly and frozen for up to three months.

Storage Notes: Leftovers can be refrigerated for up to three days.

INGREDIENTS

For the eggplant

Two pounds large Chinese or Japanese eggplants (about four total)

Quarter cup plus two tablespoons extra-virgin olive oil or grapeseed oil, divided, plus more as needed

One medium yellow onion, finely chopped

Three cloves garlic, roughly chopped

Half teaspoon kosher salt

Quarter teaspoon ground turmeric

Quarter teaspoon finely ground black pepper

Three quarters cup water, plus more as needed

For the piaz, seer and na’na dagh

One large yellow onion

Six tablespoons extra-virgin olive oil or grapeseed oil, plus more as needed

Kosher salt (optional)

1/8 teaspoon ground turmeric (optional)

Four large cloves garlic, thinly sliced

Two tablespoons dried mint

For assembly

Four tablespoons liquid kashk, divided, plus more as needed

Kosher salt

Roughly chopped raw walnuts, for garnish (optional)

DIRECTIONS

Make the eggplant: Position a rack in the upper third of the oven and preheat to 450 degrees. Line a large, rimmed baking sheet with parchment paper.

Trim the leaves of the eggplant but keep the green stem top on. Peel the eggplant and cut it in half lengthwise. (If the eggplant is very long, cut it in half lengthwise, then crosswise.)

Place the eggplant halves flesh side up on the prepared baking sheet and carefully score the eggplant in a crosshatch pattern, taking care not to pierce through. This helps the oil seep into the flesh. Brush the eggplant with a quarter cup of the oil. Use more if necessary, as eggplant absorbs a lot of oil. Sprinkle each half with salt and roast the eggplant for about 18 minutes, or until golden brown and softened but not completely cooked through. Slice off and discard the tops of the eggplant, and set aside.

In a large pan with a lid over medium heat, heat two tablespoons of oil until shimmering. Add the onion and cook, stirring occasionally, until golden, about 10 minutes. Sprinkle with a little salt, reduce the heat to medium-low, add the garlic and cook until it softens, about five minutes.

Add the roasted eggplant to the onion-garlic mixture and sprinkle on half a teaspoon of salt, the turmeric and pepper. Add enough water to reach halfway up the eggplant. Increase the heat to medium and bring to a gentle boil. Reduce the heat to medium-low, cover and simmer, stirring occasionally, until the eggplant has completely softened and cooked through and the water has been absorbed, about 20 minutes. Add a little more water if the eggplant needs longer to cook. If the eggplant is cooked through but excess liquid remains, remove the lid to cook off the liquid.

While the eggplant cooks, you can prepare the piaz, seer and na’na dagh garnishes.

To make the piaz dagh (fried onion), line a large plate with a paper towel.

Quarter the onion, then slice it into quarter-inch slices, breaking it up into individual slivers. Set aside any tiny pieces for another use, as they will burn.

In a 10-inch pan over medium-high heat, heat the oil until hot but not smoking. Add the onion and spread evenly across the pan; the onion should be shallow-frying in the oil. If not, add more oil as needed. Do not stir the onion for the first five minutes of cooking, or it will sweat instead of crisp up. Thinner or smaller pieces on the edges of the pan will fry and turn colour faster than the pieces in the centre.

When the onion starts to brown, reduce the heat to medium and stir. Season lightly with salt and continue cooking, stirring constantly now – and adjusting the heat as needed – to keep the onion from burning, until golden brown and crisped here and there, about eight minutes. Keep in mind that the onion will continue to cook and darken off the heat, so turn off the heat just before you have reached the desired shade of golden brown or auburn. If the pan gets too dry, add a little more oil. You don’t want the onion to burn, but you also don’t want it to be mushy. Just before removing the onion from the heat, add the turmeric and stir for 20 seconds. Using a slotted spoon, transfer the onions in a single layer to the prepared plate. You should get about half cup.

There should be about quarter cup of oil left in the pan. Use it for the seer dagh (fried garlic) and na’nadagh (fried dried mint).

To make the seer dagh, line a small plate with a paper towel.

Return the pan to medium heat, and heat the oil until shimmering. Add the garlic slices, reduce the heat to medium-low and fry, stirring frequently, until golden, about five minutes. Keep in mind that the garlic slices will keep crisping and turning colour off the heat, so remove them just before you think they’re done. Keep a close eye on the garlic at all times; garlic can burn quickly and turn bitter. Tilt the pan to one side so the oil pools and the garlic can cook evenly.

Transfer the garlic slices to the prepared plate. You should get about 2 tablespoons.

There should be about three tablespoons of oil left in the pan – use it for the na’na dagh (fried dried mint).

Return the saucepan to medium-low heat, and heat the oil for a few seconds. Keep in mind that your pan and the oil are already hot. Add the mint, stirring quickly for 10 seconds, and remove from the heat. Dried mint burns quickly and turns bitter. You can drizzle in more oil as you like for a thinner consistency. Transfer to a small bowl and use as needed. You should get about quarter cup.

Assemble the dish: Once the eggplant has softened, turn off the heat and, using the back of a wooden spoon or potato masher, mash the eggplant until the mixture is well combined, a little stretchy and no chunks remain.

Stir in three tablespoons of kashk and two teaspoons of the na’na dagh (fried mint) to combine. Taste, and add more kashk, if desired. Season lightly with salt, then stir and taste again; adjust the kashk and salt as needed until you get the balance of flavours you like.

In a small bowl, whisk together the remaining one tablespoon of kashk with a little water, so it’s thin enough for drizzling (if you want a generous drizzle, use more kashk and water). Drizzle on the kashk, top with as much piaz dagh (fried onion) and seer dagh (fried garlic) as you like. Follow with chopped walnuts, if using, then drizzle on about two teaspoons of the na’na dagh (fried mint). Serve warm or at room temperature.

VARIATION: To fry the eggplant: Line a large rimmed baking sheet with paper towels.

Follow the trimming/cutting of the eggplant as outlined above, but no need to score it.

In a large pan with a lid over high heat, heat the quarter cup of oil until shimmering. Working in batches, if needed, add the eggplant in one layer, cover and fry on all sides until golden brown and softened but not cooked through, two to three minutes per side, adding more oil as needed.

Keep a close eye on the eggplant and turn it often, as it can burn quickly. Take care when removing the lid as the oil can pop. Transfer the eggplant to the prepared baking sheet, then slice off and discard the tops.