Instructions

1. Trim every scrap of visible fat off the round before you slice it. Muscle dries and fat does not, and fat left on a strip is what turns a batch stale weeks before it should.
2. Cut across the grain into slices around 3 mm thick. Any thicker and the run will not reach the middle of a strip before it ends.
3. Juice the carrots, celery and ginger and whisk them into the soy and Worcestershire with the brown sugar. The vegetable juice is doing the job a shop marinade gives to plain water, and it carries a sweetness the soy alone has not got.
4. Stir the pepper, cayenne, cumin, onion powder and crushed chilli in last, then add the strips one at a time. Dropped in as a handful, the dry spice cakes between slices instead of coating them.
5. Refrigerate the lot overnight and turn it once if you are passing. Round is a lean, tight cut and lets a marinade in more slowly than flank does.
6. Lift the strips onto a rack and let them drip for ten minutes before they go on the trays. Pepper suspended in liquid runs to the lowest edge of a strip and burns there.
7. Dry at 65 °C for 6 hours. Five pounds of beef fills a machine, so rotate the trays at the midpoint, since whatever sits nearest the fan finishes well ahead of the rest.
8. Pull a strip out, let it cool, and bend it: it should crack along the fold and show dry fibres rather than a moist red line. Judging a hot strip is how people end up with jerky that moulds in the bag.
9. Sealed in the fridge it lasts a fortnight, and vacuum sealed in the freezer six months. This marinade is built on fresh vegetable juice with no curing salt in it, which is why it has no business in a cupboard.