The Ultimate Homemade Ketchup (Lacto Fermented)

Ingredients

• 340 grams Tomato Paste (Two 6‑ounce cans, blended until smooth)
• 73 milliliters Water (Room temperature)
• 42 grams Granulated Sugar (White granulated sugar)
• 5 grams Kosher Salt (Fine kosher salt)
• 45 milliliters Whey (or brine from lacto‑fermented veg) (Liquid from a lacto‑fermented vegetable jar; provides starter cultures)
• 60 milliliters Apple Cider Vinegar (Raw, unfiltered)
• 236 milliliters Mayonnaise (Homemade or store‑bought, optional for burger sauce)
• 30 milliliters Pickles (finely diced) (Optional garnish for sauce)
• 15 grams Black Garlic (Finely chopped, optional flavor boost for sauce)

Instructions

1. Make sugar‑water syrup

   Combine 73 ml water and 42 g granulated sugar in a small saucepan. Heat over medium heat, stirring occasionally, until the sugar is fully dissolved. Remove from heat before the mixture reaches a boil.

   Time: PT5M

2. Combine tomato paste and seasonings

   In a medium mixing bowl add the 340 g tomato paste, 5 g kosher salt, the warm sugar‑water syrup, 45 ml whey (or brine), and 60 ml raw apple cider vinegar. Mix thoroughly until the mixture is completely smooth.

   Time: PT5M

3. Pack mixture into mason jar

   Using a funnel, spoon the ketchup mixture into a clean 1‑pint mason jar, leaving about 1‑2 cm headspace. Secure the jar with the two‑piece lid and attach the airlock.

   Time: PT2M

4. Ferment at room temperature

   Place the sealed jar in a room‑temperature spot (68‑72 °F / 20‑22 °C) out of direct sunlight. Let it ferment for 2‑4 days, checking daily for tiny bubbles in the airlock. The ketchup will develop a deeper, more acidic flavor.

   Time: PT72H

   Temperature: 68‑72°F

5. Finish and store

   After fermentation, optionally pass the ketchup through a fine mesh sieve or chinois for a smoother texture. Transfer to a clean container and refrigerate.

   Time: PT5M

6. Prepare fermented ketchup burger sauce (optional)

   In a bowl combine 236 ml mayonnaise with 118 ml of the fermented ketchup. Season generously with salt and stir in optional finely diced pickles and chopped black garlic. Mix until fully incorporated.

   Time: PT5M

Nutrition Facts

Calories

20

Protein

0g

Carbohydrates

5g

Fat

0g

Fiber

0g