Go to an Indian grocery and get the whole coriander seed. Get a cheap burr grinder. There are great deals on the refurb Cuisinart online. Size of cup (8 oz) doesn’t matter just use the same cup to measure everything except the vinegar. It is the proportions. Think of making lasagna. That is how you build the marination stack. Spice at the bottom of your glass tray, meat, spice, vinegar, meat, spice, vinegar, meat, spice, vinegar, etc. I apply the spice rub first and it needs to be applied like a light BBQ rub. I apply the vinegar throughout the process. just a decent sprinkle. You don’t want it swimming but you do want it wet. Cover with plastic wrap and toss in the fridge overnight. Malt vinegar or white vinegar only but malt adds good flavor. Never tried balsamic but suspect it would not taste right.
Thank you, well noted. The size of the cup is for dosing the meat weight, since I’ll experiment with smaller quantities first. Nice tips about the different types and usage of Biltong.