This past weekend’s Virtual Ferment Fest was an absolutely fabulous, heart-lifting, globe-spanning microbial love fest. For  the festival, I did a short and sweet demo on making kosho, a citrus and hot pepper paste and also my favorite condiment for all occasions. Watch me ham it up for the camera here. Or follow the written recipe below.

I like doing these demos, and want to make them a regular thing. If there is a fermentation technique (or other kitchen skill!) you’d like to be guided through live, shoot me an email at

As you’ll see, this is more a loose guide than a recipe. I’m not telling you what exactly to use or how much. I want you to use your sensorial judgment. Be confident in your kitchen abilities and taste as you go!


  • Citrus (whatever you like, but skip the super sweet stuff like oranges, or use sparingly in combination with more acidic options like lemons and limes)
  • Hot peppers (pick your poison)
  • Salt


  • Slice off a small segment of citrus that includes the rind and take a bite. If it isn’t crazy bitter, use the entire fruit. Simply slice and deseed. 
    If it is unpleasantly bitter, just use the rind and juice (not the white pith between the fruit and peel). Feel free to mix different types of citrus together. As for quantity, 2-3 medium lemons will make approximately 1 cup of kosho.
  • Prep the hot peppers.
    -If using a super hot variety, you may want to remove the seeds and interior white veins.
    -If using something milder, simply remove the stem.
    As for quantity, it’s all about preference. If I’m using something very mild like Shishito pepper, I might do equal parts citrus and peppers. If using something very hot, I’ll just throw one or two peppers in. For two lemons, one or two jalapeños is plenty hot for me. 
  • Blend citrus and hot peppers together in food processor. I prefer the consistency a bit on the chunky side.
  • Tightly pack the mixture into a clean mason jar, removing as many air pockets from the mixture as possible.
  • Weigh the contents of the jar to calculate how much salt to add. 
    An easy way to do this is by getting two jars of the same type — one empty and one filled with the mixture. Weigh the empty one on a kitchen scale, and press “tare” on the scale. Then switch it out for the filled jar. 
    Calculate 2 percent the weight of the mixture in salt. So if the mixture weighs 250 g, that would be 5 g salt, about a teaspoon’s worth. Also, don’t feel like bothering with weighing out all the ingredients? A teaspoon or two of salt per cup of citrus-pepper mixture should be just right.
  • Sprinkle the salt on top of the mixture. Use a wet cloth to clean the exposed interior sides of the jar and remove any bits of the mixture clinging to the walls (it’s unlikely, but they could get moldy).
  • Loosely cover and allow to ferment at room temperature for three days to two weeks. Since this is such a salty, acidic environment, it’s highly unlikely that any mold will grow on the mixture. If for whatever reason it does, just use a clean spoon and carefully skim it off, and then wipe again the interior sides of the jar.
  • When happy with the flavor, seal tightly and store in the fridge indefinitely.