Pressure Cooker Anko (Red Bean Paste) 粒あん・こしあん (圧力鍋)

• Gather all the ingredients.
  
• Put 1½ cups azuki beans in a strainer and place it inside a large bowl. (If using 1 250-g bag, use 1¼ cups azuki beans.) Rinse the azuki beans in running water until the water is clear. Discard any pieces that are floating. Drain the water.
  
• Transfer the beans to your stovetop pressure cooker or the inner pot of an Instant Pot. Next, add 5 cups water to the pot. (For 1 250-g, add 4 cups water.)
  
• Cover and lock the lid of your pressure cooker. If you’re using an Instant Pot, turn it on and press the Bean/Chili button. Press the “minus“ button to decrease the cooking time to 25 minutes from the default 35-minute cooking time.
  
• Before you walk away, make sure the steam release handle points at Sealing and not Venting.
  
• If you’re using a stovetop pressure cooker, cook on high heat until you reach high pressure. Then, reduce the heat to low to maintain the pressure for about 20 minutes.
• When it’s done cooking, the Instant Pot will switch automatically to the Keep Warm mode. Let the pressure slowly release by itself for 15–20 minutes. If you are using a stovetop pressure cooker, remove the pot from the heat, and let the pressure release naturally. Before opening the lid, turn the steam release handle to Vent and release any remaining pressure.
  
• Skim the foam off the surface and discard (if you prefer a more refined taste). Pick up one bean and mash it with your fingers. If it mashes easily, it‘s done. If the beans are still not done, close the lid and cook again under high pressure for a few more minutes, adjusting the time based on how underdone the beans are. Tip: If your beans were not done after the initial cook time, it could mean that your beans are a bit old. Next time, try using fresher beans for more consistent results.
  
• If you‘re making Zenzai or Oshiruko (Red Bean Soup), DO NOT DRAIN and continue to the next step with the cooking liquid remaining in the pot. To make Anko, drain the azuki beans through a fine-mesh sieve and put the azuki beans back in the inner pot.
  
• Next, add 1¼ cups sugar to the pot. (For 1 250-g bag, add 1 cup sugar.) Press the Sauté button and select the Low option.
  
• Let the sugar dissolved completely, stirring occasionally with a wooden spoon. Then, add ⅛ tsp Diamond Crystal kosher salt (For 1 250-g bag, add ⅛ tsp Diamond Crystal kosher salt.) From here, you can make one of three variations: Anko with a fine texture, Anko with a course texture, or sweet red bean soup.
  

Option 1: Koshian (Fine Red Bean Paste)

• Continue cooking as you let the moisture evaporate. When you can draw a line through the azuki bean mixture and see the bottom of the pot for 1 second, turn off the heat. Take out the inner bowl from the Instant Pot and let the mixture cool for 5–10 minutes*. The mixture will thicken more as it cools down. *Important: If you purée hot liquid in the food processor or blender, the liquid may start coming out the edges of the food processor or the built-up steam can actually blow the lid off the blender. To prevent this from happening, it’s best to let the liquid cool for a few minutes.
  
• After 5–10 minutes of cooling, transfer the azuki beans into a food processor or blender. Fill it only halfway and work in 2–3 smaller batches, if necessary. I use a 14-cup food processor so the mixture will all fit at once. Tip: If you prefer the traditional method, use a very fine-mesh strainer and press the mixture with a wooden spoon. The azuki bean skins will be separated and you will get a more refined koshian.
  
• Run the food processor or blender until the mixture becomes a smooth texture. If it looks too soft, don’t worry. It will dehydrate and thicken even more when the paste is completely cool. Tip: If you‘re using a blender, remove the center cap from the lid and hold a kitchen towel over it while blending. 
  
• Transfer to an airtight container. When it has cooled and thickened more, the koshian is now ready to use in a variety of Japanese sweets such as Strawberry Mochi (Ichigo Daifuku), Sakura Mochi, Manju, and Mizu Yokan. To store, cover and store in the refrigerator for up to 4 days and in the freezer for up to a month. I recommend dividing and wrapping 100 g portions in plastic film and storing it in a freezer bag. When you’re ready to use, defrost it in the refrigerator overnight. Tip: Compared to store-bought red bean paste, homemade anko uses less sugar and therefore doesn‘t keep as long.
  

Option 2: Tsubuan (Chunky Red Bean Paste)

• Continue cooking as you let the moisture evaporate. When you can draw a line in the azuki bean mixture with the wooden spatula and see the bottom of the pot for 2 seconds, turn off the heat. Transfer the mixture to a baking sheet (or flat-rimmed plate) to let it cool.
  
• When it has cooled and thickened, the tsubuan is now ready to use in a variety of Japanese sweets such as Daifuku Mochi, Anpan, Red Bean Pancakes, and Matcha Zenzai (Red Bean Soup). To store, transfer to an airtight container and store in the refrigerator for up to 4 days and in the freezer for up to a month. I also recommend dividing and wrapping 100 g portions in plastic film and storing it in a freezer bag. When you’re ready to use, defrost it in the refrigerator overnight.

Option 3: Zenzai or Oshiruko (Red Bean Soup)

• Keep the cooked azuki beans and their cooking liquid warm over low heat. If you like the soup without chunky beans, you can mash them with a potato masher or a hand blender. Mash most of the beans but keep some whole for texture. I like my red bean soup with chunky beans so I don‘t mash them. Serve hot in individual bowls and top each with a piece of toasted mochi. For instructions on how to prepare the mochi, see my Zenzai blog post and recipe. To store, transfer to an airtight container and store in the refrigerator for up to 4 days and in the freezer for up to a month.