Wash vegetables. Cut carrots into 1/2 centimeter rounds. Cut cauliflower into florets. Cut celery into 1/2 centimeter slices. Cut peppers in halves, remove stems and seers and cut into 1/2 centimeter slices.
Wash jars and lids with hot soapy water. Place on a clean towel.
Bring 3-4 liters water to a boil.
To the bottom of each jar, add 100 ml apple cider vinegar, 1 tbsp salt. 3 tbsp sugar and 3 peppercorns (optional). Layer vegetables -carrots, cauliflower, celery, peppers. Fill to the top, press, to get more vegetables in, but do not squish.
Top with hot water, filling jars almost to the top. Close lids. Close tight!
Fill a large canning pot with water. Add jars. Bring to a boil and boil for 5 minutes.
Remove from the pot and let jars cool to room temperature.
Store in a cool and dry place for up to 6 months. Once you open a jar, store in the fridge for up to 1 week.