Cold brew brewing and holding vessel

Holds coffee and cold water in contact for a long unattended period, separates them cleanly at the end of it, and then holds the resulting batch as a food until it is sold.

Cold brew is a slow extraction at ambient or refrigerated temperature, and the equipment question is almost entirely about SEPARATION and about the HOLD — not about the brewing, which happens on its own whatever it happens in. Two families. IMMERSION keeps grounds and water together in one vessel for the whole period and then parts them, either by lifting a filter basket or brew bag out or by draining the liquid down through a filter. Everything that goes wrong with immersion goes wrong at that moment: a weave too coarse sheds fines into the batch, a basket full of saturated grounds is far heavier than the person who has to lift it expects, and a filter that clogs turns a five-minute drain into an hour of standing over it. SLOW DRIP passes cold water through a bed of grounds one drop at a time under gravity, so extraction and separation happen continuously and there is nothing to lift; it produces a different and usually lighter cup, it is a display object, and its drip rate is a manual adjustment that drifts while nobody is watching. The property that outranks both families is that a completed batch is A LARGE VOLUME OF FOOD, HELD FOR A LONG PERIOD, IN A VESSEL NOBODY IS WATCHING — often at ambient temperature for the brewing part of its life. That makes the vessel a food-safety object before it is a brewing one: food-grade, sealable, labellable, cold-held where the site's standard requires it, and cleanable all the way to the seal and the tap. Every decant between vessels is another handling, another surface and another chance to lose the label, so the cleanest equipment answer is a vessel the coffee is brewed in, held in and dispensed from, where the liquid is exposed once.

• SIZE FROM THE HOLD, NOT FROM THE BREW. A batch occupies a vessel and a shelf of cold storage for the whole of its life, not just while it is brewing, so the binding constraint in almost every bar is refrigerated space rather than brewing capacity. Measure the fridge, and measure it with everything else that has to live in it, before you choose a vessel size.
• Buy for the SEPARATION STEP, because that is where the labour, the mess and the injuries are. Lift a full basket at the working height it will actually be lifted at, with wet hands, before committing to a size. A vessel one person cannot decant safely at the end of a shift will be decanted badly, decanted late, or left for somebody else.
• Prefer a vessel the coffee is brewed in, held in and dispensed from. Every decant is another handling, another surface, another chance for the batch to lose its label, and another point at which a busy person makes a judgement about a container they did not fill.
• Treat LABELLING as an equipment decision here, not as paperwork. Buy vessels with a surface a label sticks to and comes off cleanly, or with an integral writable panel. A batch whose age cannot be established is a batch nobody can make a decision about, and what happens to it is set by the site's food-safety standard rather than by whoever finds it.
• Ask at purchase how the tap, the seal and the gasket come apart, and whether spares are available and from whom. Any part that cannot be stripped will be rinsed, and a tap is the one component on a cold brew vessel that holds liquid out of sight between services.
• Take the recipe from the cold brew SOP, never from the leaflet the vessel arrived with. A supplier's suggested method was written for an unnamed coffee at an unnamed grind in unnamed water, and this entry deliberately states no ratio, time or yield for the same reason — the method has one owner and it is not the equipment page.
• Decide refrigerated against ambient brewing before you buy, and decide it against the site's food-safety standard rather than against the space you happen to have. It changes the cold storage this purchase requires, and discovering that after the vessels arrive means either a second fridge or a method nobody signed off.
• Plan the batch cadence against demand and against the fridge together. Cold brew's real problem is never making it — it is having the right amount ready: too little and the menu item is off for a day and a half, too much and a dated batch is discarded. Both failures are cheaper to design out than to manage.
• Assess nitrogen or any pressurised dispense as an installation, not as an accessory. Gas supply, regulator, line, coupler, cleaning routine, spares and somebody to call — the vessel is the smallest part of that decision and the only part most people cost.