For my home-made ketchup, I use
Calvé mayonnaise because it is unparalleled in flavour and is virtually zero carbs. For U.S. option click
HERE.
Metric kitchen scales are an inexpensive yet invaluable gadget to enable accurate measurement of ingredients. Store them upright in a cupboard or over your worktop and they'll only take up a tiny bit of space. Click
HERE for the ones I use. For U.S. option click
HERE.