Bowl of plain yogurt on white background.

Activating The Culture:

Thermophilic Quark

Before we begin let’s discuss some side notes. Be sure to read our FAQs and activation page thoroughly before you begin.

  • The first three batches need to be done back-to-back (one right after the previous batch, with no more than 24 hours in between batches).

  • Our quark is an heirloom culture, meaning you can use a portion of your last batch to make the next one.

  • The cultures will not fully dissolve, and you may notice some lingering culture flakes in the next batch or two. This is very normal.

  • Ensure that you refresh your quark by preparing a new batch every five to seven days. If you need to take a break, freeze some quark in ice cube trays, and when you’re ready, just pop out a couple of cubes. Depending on how old the quark cubes are, you might need to double the amount of starter.

  • Always keep a backup in the freezer and replace it every couple of months. Regularly rotating your backup will keep your cultures fresh.

  • The first batch of quark may be runny or still liquid, which is normal during activation. The texture and flavor will develop over several batches.

  • Quark cheese needs straining to get rid of some whey. If you're eating it like yogurt, you can skip straining or strain just a little. The drier the cheese, the longer you should strain it.

  • Thermophilic quark thrives between 90°F and 115°F. If you are fermenting at the lower end of this temperature range, be aware that the fermentation process will take significantly longer. It may require a couple of additional batches to achieve full activation. The temperature range provided in the instructions below reflects my personal preference. I have a strong inclination towards longer ferments for my yogurt. The additional culturing time truly enhances and rounds out the flavors, resulting in a richer and more complex taste that I can’t get when fermenting at higher temperatures.

  • Each packet contains enough starter to technically activate two batches. If you choose to use only half of the packet, please ensure that you adjust the quantity of milk accordingly.

Activating The Culture

  1. Heat 1 cup of pasteurized milk to 180 degrees Fahrenheit on the lowest stove setting. The longer you keep it at this temperature, the thicker the quark will become. You can skip the heating of the milk entirely if you use UHT (ultra-pasteurized) milk and simply heat your milk to culturing temperature.

  2. Remove the milk from the heat and allow to cool to 95-105 degrees Fahrenheit.

  3. Pour cooled milk into a container and add the quark starter culture. Mix well.

  4. Cover the mixture and incubate at 95-105 degrees for 5-12 hours in a yogurt maker or similar appliance.

  5. Once it has set, OR at the end of 12 hours (whichever comes first), turn off the yogurt maker and allow it to cool for about an hour. The first batch may still be liquid; this is fine and normal. Keep going with your second batch. The flavor and texture should improve over the next several batches.

    (Optional) Place in refrigerator for six hours to help further thicken the quark.

  6. You can now go on to the next step in the activation process and make your next batch of quark.

    For Instant Pot or similar devices, activation batches are best fermented in mason jars. Just pop them on top of the rack and pour a bit of water underneath.

Making Batch 2-3

  1. Heat 1 cup of pasteurized milk to 180 degrees Fahrenheit on the lowest stove setting. The longer you keep it at this temperature, the thicker the quark will become. You can skip the heating of the milk entirely if you use UHT (ultra-pasteurized) milk and simply heat your milk to culturing temperature.

  2. Remove the milk from the heat and allow to cool to 95-105 degrees Fahrenheit.

  3. Add 1 TBSP of quark from batch one and mix well.

  4. Pour the milk into the container, cover the mixture, and culture for 5-12 hours at 95-105 degrees Fahrenheit. After 5 hours, check the quark frequently by tilting the jar gently. If the quark moves away from the side of the jar in one mass instead of running up the side, it is finished culturing.

  5. Once it has set, turn off the yogurt maker and allow it to cool for about an hour.

    (Optional) Place in refrigerator for six hours to help further thicken the quark.

  6. Repeat this process to create batch three, using the starter from batch two this time.

How To Make Larger Batches

Once the culture is fully activated and consistently producing good results, only then should you scale up your batches. You may need to give your culture another batch or two to fully activate. Please don’t scale up before the culture is fully awake, as doing so could overwhelm the bacteria and cause your quark to fail.

For every cup of milk, incorporate one tablespoon of your previous batch of quark. Ensure that the starter is not more than seven days old.