Sous vide is forgiving about timing and unforgiving about a handful of specific things.

Not Following a Table

The most consequential one. Times and temperatures are not interchangeable and cannot be inferred from a recipe for something else.

Required time depends on temperature, thickness and food type, and it starts when the core reaches the bath temperature rather than when the bag goes in.

Use a published table from a food safety authority or a reputable reference, and follow it fully.

The Practical Ones

• Not sealing properly, so the bag fills with water
• Letting bags float, so part of the food is not cooked
• Overcrowding, so water cannot circulate around each bag
• No lid on a long cook, so the level drops and the unit trips
• Not drying the surface before searing
• Searing for too long, which undoes the evenness

Racks, lids and appropriately sized containers, of the kind catalogued at https://everie.us.com/, address most of that list mechanically rather than requiring vigilance.

Leaving It to Cool in the Bath

The safety mistake. When a cook finishes, the food either gets eaten or gets chilled rapidly.

Leaving a bag in cooling water passes it slowly down through the range where bacteria multiply, sealed and without oxygen, which is exactly the condition to avoid.

Ice bath, then refrigerate or freeze.

Assuming Longer Is Always Fine

True for tough cuts and false for everything else.

Fish breaks down within hours. Lean meat becomes soft and mealy. Vegetables go to mush. The window is wide, not infinite.

Cooking Below the Floor

Below roughly fifty-four or fifty-five degrees Celsius, pasteurisation effectively stops.

Short cooks of whole cuts are treated like a rare steak. Long cooks at those temperatures are a different proposition entirely, and mince and tenderised meat follow conventional guidance regardless.

Too Much Liquid in the Bag

Sous vide concentrates rather than dilutes, so marinades and stock go much further than expected.

Too Much Salt or Aromatics

Nothing escapes, and hours in a bag with garlic is stronger than it sounds.

Not Checking on a Long Cook

Level and bags, before bed.

Start With Steak

Short, forgiving and instructive.