Before you start
Every quest runs on three things: clean gear, the right salt, and the right temperature. Get those right and most batches work first time.
Wash jars, lids, cloths and tools in hot soapy water and rinse well. Ferments need the good bacteria already on the vegetables, so you don't need to sterilise. For cheese and yoghurt, scald your pot and spoons with boiling water first.
Iodine and anti-caking agents slow fermentation and cloud brine. Weigh salt on kitchen scales rather than using spoons, because grain sizes vary a lot.
Cheese and yoghurt live or die by temperature. The Soft Cheese Kit includes a digital thermometer; any probe thermometer works.
Your kit holds the gear. Fresh ingredients come from your local shop, and each guide lists exactly what to buy.
Temperature targets
| Quest | Ideal temperature | Too warm means |
|---|---|---|
| Vegetable ferments | 18–22°C | Soft, mushy veg |
| Yoghurt incubation | 40–45°C | Thin, grainy yoghurt |
| Sourdough starter | 22–26°C | Runny, fast-peaking starter |
| Ricotta and paneer | 85–90°C before adding acid | Rubbery curds if boiled hard after |
| Mozzarella | 32°C to set, 57°C to stretch | Curd won't set if milk is too hot |
Good signs vs bad signs
| You see | What it is | What to do |
|---|---|---|
| Bubbles, cloudy brine, sour smell | Fermentation working | Nothing, it's perfect |
| Flat white film on brine | Kahm yeast, harmless | Skim it off; keep veg under brine |
| Grey liquid on sourdough starter | Hooch: a hungry starter | Pour off or stir in, then feed |
| Fuzzy blue, green, black or pink spots | Mould | Throw the batch out |
| Slimy texture or rotten smell | Spoilage | Throw the batch out |
Salt: which to use
- Pickling salt or cooking salt labelled "non-iodised"
- Pure sea salt flakes or fine sea salt
- Kosher salt
- Iodised table salt
- Salt with anti-caking agents (check the ingredients)
Gear you already own
- A large heavy-based pot (4 L or more for mozzarella)
- Digital kitchen scales
- A big mixing bowl, slotted spoon and ladle
- Wide-mouth glass jars for ferments
- A blender (tofu only)
Food-safety basics
- Wash your hands before you start and after handling raw ingredients.
- Keep finished cheese, yoghurt, tofu and ferments in the fridge at 5°C or below.
- Use pasteurised milk from the supermarket, never raw milk.
- Keep ferments fully under their brine; air exposure is where mould starts.
- If you're pregnant or have a weakened immune system, check official food-safety advice on soft cheeses and ferments first.
Words you'll see in the guides
- Brine
- Salt dissolved in water. Keeps veg submerged and bad bacteria out.
- Headspace
- The gap between the food and the jar's rim. Ferments bubble up into it.
- Curd and whey
- The solids and the liquid that milk splits into when you add acid or rennet.
- Clean break
- When set milk splits cleanly around a knife: the sign mozzarella curd is ready to cut.
- Coagulant
- What turns soy milk into curds: lemon juice, vinegar or nigari.
- Kahm yeast
- A harmless flat white film on ferments. Skim it off.
- Hooch
- Grey liquid on a hungry sourdough starter.
Ready to pick a quest?
Ricotta, labneh and sauerkraut are the easiest first batches.