For a typical gammon joint in a slow cooker, you’re usually looking at around 4–5½ hours on high/medium, or 6–8 hours on low , depending on size and your cooker model.

Quick Scoop

  • Small gammon (about 700–900 g): around 2–3 hours on medium (or roughly 4 hours on low).
  • Medium gammon (1–1.5 kg): about 4–4½ hours on high, or 7–8 hours on low.
  • Larger gammon (1.5–2.5 kg): roughly 4½–5½ hours on high/medium, or 6–8 hours on low.
  • Internal temperature: aim for about 71–75°C in the thickest part, or until the juices run clear and the meat feels very hot when pierced.

If you like your gammon just sliceable, stop closer to the lower end of the time range; if you want it more “pulled ham” style, let it go towards the upper end.

Handy time ranges (by setting and size)

Here’s an approximate guide; always use it with a temperature check or doneness check:

[8] [1][3][5] [1][5] [7][3] [9]
Gammon size Slow cooker setting Approx. time Notes
700–900 g Medium 2–3 hours Check for 68–71°C internal temp; should be tender but hold its shape.
1–1.5 kg High 4–4½ hours Common timing for water/cola or sugar-based recipes.
1–1.5 kg Low 7–8 hours Great if you want to leave it all day; very tender.
1.5–2.5 kg High / Medium 4½–5½ hours Used in many cola-gammon recipes; still sliceable.
Any (joint size varies) Low 6–8 hours General BBC-style guidance; longer time gives “pulled ham”.

Simple method (story-style walkthrough)

Imagine it’s a Sunday morning, you’ve got a 1.2 kg gammon joint, and you want it ready by dinner without hovering over the hob.

  1. Nestle the gammon into your slow cooker with aromatics (onion, carrot, bay, peppercorns, or a cola/juice/brown-sugar base, depending on your recipe).
  1. Pour in enough liquid (water, cola, or juice) to cover or nearly cover the joint.
  1. Cook:
    • On low for about 7–8 hours if you’re going out all day, or
    • On high for about 4–4½ hours if you’re starting later and eating sooner.
  1. Check doneness by:
    • Probing to 71–75°C in the thickest part, or
    • Piercing with a knife or fork – juices should run clear and the fork should feel very hot to the touch.
  1. For a festive touch, many cooks lift it out, remove the skin, score the fat, brush with a honey–mustard or sugar glaze, and finish in a hot oven (around 180–190°C) for 20–30 minutes to get a sticky, caramelised crust.

Across UK forums and recipe sites, this style of slow-cooked gammon has become a kind of modern Christmas and Sunday-lunch tradition, especially when people want a low-effort, all-day simmer that frees them up for everything else.

Little timing tips and “what ifs”

  • If your slow cooker runs hot: Start with the lower end of the time range and rely on a thermometer or doneness checks. Many modern models cook faster than older ones.
  • If the joint is very thick: Add 30–60 minutes, especially on low; the centre takes longer to come to temperature.
  • If you prefer very soft, shreddable meat: Aim for the upper end of the low-setting range (closer to 8 hours or slightly more).
  • If you’re glazing afterwards: Slight undercooking is not recommended; instead, cook to safe temperature in the slow cooker, then treat oven time as purely for colour and flavour.

Mini FAQ

  • Can you overcook gammon in the slow cooker?
    Yes, after a point it will start to break down into stringy pieces, which some people like for pulled ham but others find too soft.
  • Do smoked and unsmoked take different times?
    The timing is broadly similar; the main difference is flavour and whether you pre-soak (which most modern recipes say you can usually skip).
  • Is cola or apple juice essential?
    No. They’re popular “forum favourite” twists for sweetness and colour, but a simple water-and-onion base works perfectly well.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.