Wear gloves while handling the jalapenos. Remove the stems and slice the peppers into 1/4-inch rounds, leaving the seeds and membranes in for maximum heat or removing some for a milder batch.

Combine the 5% acidity apple cider vinegar, sugar, turmeric, celery seed, garlic, and cayenne in a large nonreactive pot. Bring the mixture to a boil over medium-high heat, stirring until the sugar dissolves, then boil for about 5 minutes.

Add the sliced jalapenos to the boiling syrup and return the mixture to a boil. Cook for approximately 4 to 5 minutes, stirring occasionally, until the peppers soften slightly but remain recognizable and somewhat crisp.

Use a slotted spoon to pack the hot peppers into hot, sterilized half-pint canning jars. Leave about 1/4 inch of headspace in each jar, then ladle the hot syrup over the peppers while maintaining the same headspace.

Remove air bubbles, wipe the jar rims clean, and apply the lids and rings. Process the jars in a boiling-water canner for 10 minutes, adjusting for altitude according to current canning guidance.

Let the jars cool undisturbed, then check the seals. Refrigerate any jar that does not seal, and remember that the syrup thickens somewhat as it cools.