Instructions
Notes
- The portobello or field mushroom produces the darkest, most intensely flavoured ketchup and is worth using if you want maximum depth. Button mushrooms produce a lighter result that is perfectly good but less complex.
- The spice combination is adaptable. Glasse's original combination of ginger, whole pepper, mace and cloves is the historically documented version. My combination of nutmeg, allspice and black pepper produces a warmer, slightly sweeter spice note. Both are defensible. The spices should be present but subtle. If you can distinctly taste the nutmeg or the allspice above the mushroom flavour you have used too much.
- The salt quantity seems alarming but is correct and necessary. The salt is doing two jobs simultaneously: drawing the liquid from the mushrooms through osmosis and preserving the finished product. A properly salted mushroom ketchup will taste seasoned and savoury rather than aggressively salty in the finished product because the reduction concentrates the mushroom flavour to the same degree it concentrates the salt.
