Advanced options
The rule: 20 minutes per 450g plus 20 minutes: same arithmetic simmered or roasted (roast at 180C fan 160C, covered in foil until the glaze stage). Modern gammon rarely needs pre-soaking, but if you're salt-sensitive, soak overnight or simmer in plain water and discard it. Gammon becomes HAM by being cooked: you're making ham: the Boxing Day sandwich stock rises accordingly.
What The Gammon Cooking Time Calculator Works Out
- Cooking time: 20 minutes per 450g plus 20 minutes, the same arithmetic as the roast joints. A 2kg family joint wants about an hour and fifty minutes; a 5kg Christmas boiler nearly four hours. The formula holds for both methods.
- The glaze finish: skin off while warm leaving the fat, a diamond score, cloves if you like, then honey-mustard, marmalade or a cola reduction brushed on and roasted hot at 200C plus for the final 25-30 minutes until lacquered.
- Doneness check: 68-70C in the centre on a probe thermometer, which defines done more honestly than any clock; it climbs a couple of degrees resting. Rest 15-20 minutes before carving.
- Weight in pounds (advanced): enter the label weight in lb and it is converted (1lb = 0.4536kg).
- Minutes per 450g and extra minutes (advanced): edit the rule of thumb for your oven or a boneless joint: some butchers quote 25 minutes per 450g for bone-in, and slow-cooker recipes run their own clocks.
- Carving time, resting time and timeline (advanced): counts back from when you want to carve to give the time to start the simmer or oven, when to switch to the glaze, when it comes out and the overnight soak if you choose one.
- Serves (advanced): about 200g of raw gammon per person served hot; the joint stretches far further cold. Enter your guests to see the raw weight left for Boxing Day sandwiches, or how much short the joint is.
- Cost (advanced): the joint at your price per kilo (gammon runs GBP 5 to GBP 8 a kilo against the turkey-season premiums on everything else) and the cost per hot portion. The simmer liquid becomes the stock pea and ham soup was built on.
- Soaking (advanced): contemporary curing is mild enough that the overnight soak is insurance for the salt-sensitive rather than doctrine; the simmer method discards most of the surplus anyway.
- Pan and liquid (advanced): roughly 1.5 litres of water per kilo to cover a simmered joint, or a deep tin with loose foil for the oven method, and what to keep from each.