Cold soaking: which foods work, how long they take, which don’t

What soaks in cold water, and how long it takes

Cold soaking means rehydrating a meal “by soaking it in treated water instead of cooking it”, in REI’s words.¹ The same question for our own pouches is answered in freeze-dried meals with cold water; what follows is food anyone can buy. Food that was cooked before it was dried, and small pieces, soak fastest. REI’s rule of thumb: “the crunchier the raw food, the more time it will likely take to rehydrate”, so pasta and rice take far longer than instant mash or couscous.¹ Its suggested times are below, with REI’s own caveat: “Rehydration time can vary.”

REI also lists dehydrated macaroni and powdered hummus among the foods that soak well, and suggests jerky, salami, tuna, nuts or nut butter to add protein that needs no water at all.¹ Of those, the nuts and nut butter carry the most for their weight, as the tables in backpacking food by calorie density show.

The method, jar to spoon

Step by step

1. Pick the jar

   One with a good seal, says the Washington Trails Association: at least about 470 ml (16 oz), more if you eat a lot, and wide and shallow enough for a spoon to reach the bottom.²

2. Measure the food at home

   REI’s advice is to work out the proportions before you leave, so you know how much water covers your portion.¹

3. Pour treated water to cover

   Filtered or purified water, until the food is covered.¹ Water from a stream goes through your filter or treatment first;² the methods are in how to make water safe to drink.

4. Close it and keep walking

   Time 30–60 min

   REI suggests starting the soak about 30 minutes to an hour before you expect to reach camp, depending on what’s in the jar.¹

5. Stir and eat

   Stir right to the bottom, then eat it straight from the jar.

6. Rinse it straight away

   Pour in a little clean water, put the lid on and shake, immediately after eating.²

How long soaked food can wait

The food-safety authorities have no rule for cold-soaked food as such; their rules are for food kept out of the fridge. Once the water is in, dried food is prepared food, so on our reading of those rules the clock starts when the water goes in. REI makes the same link: it warns that food left in lukewarm conditions grows bacteria and points to the USDA’s guidelines.¹

WHO Europe’s summer advice adds the other half of any soak: “Use safe water or treat it to make it safe.”⁸

A soak started 30 to 60 minutes before camp sits well inside the two hours the USDA, AESAN and WHO Europe give. A jar filled at breakfast and carried in a warm pack until evening does not.

Worked through for a summer evening with camp at 19:00: couscous, at REI’s 5 to 10 minutes, can go in at about 18:50, and ramen, at 20 to 30 minutes, at about 18:30. Both are eaten well inside two hours of the water going in. Pasta, at 1 to 2 hours, has to start by 17:00, and on an afternoon above 32 °C (90 °F) a two-hour soak is already past the USDA’s one-hour figure before you eat. That’s the case for leaving pasta at home and taking couscous.

When leaving the stove isn’t worth it

The average backpacking cook kit weighs “somewhere between 16 and 24 ounces”, REI says: about 450–680 g.¹ That is what cold soaking saves, and REI adds that many hikers prefer it during fire bans, to reduce the risk.¹ In southern Spain the summer fire rules reach the stove too, and camping food with no fridge and no flame sets them out.

REI lists three reasons to keep the stove. In the cold, “leaving a stove behind can pose a safety risk”. Some foods don’t rehydrate well, or quickly, in cold water. And a stove is “a great back-up water purifier”.¹ So on a winter trip, at a cold high camp or through a week of doubtful water, the 450–680 g earns its place.

Freeze-dried meals in cold water

Whether a freeze-dried meal from any maker works cold is for that maker to say, on the label. The water is the same as for a jar: drinking water, or water you’ve treated. Most of our pouches work with cold water too, 20–30 minutes depending on the meal; the table has three of them.

Three of ours with cold water

Pouch	Water	Hot water	Cold water
Lentil & Vegetable StewLarge	490 ml	8 min	about 30 min
Porridge & Fruit	250 ml	5 min	about 20 min
Guacamole	120 ml	Cold water only	5 min

Three of ours with cold water

• Lentil & Vegetable StewLarge

  Water

  490 ml

  Hot water

  8 min

  Cold water

  about 30 min

• Porridge & Fruit

  Water

  250 ml

  Hot water

  5 min

  Cold water

  about 20 min

• Guacamole

  Water

  120 ml

  Hot water

  Cold water only

  Cold water

  5 min

The Lentil & Vegetable Stew, a vegan lentil stew, takes about 30 minutes cold; the Porridge & Fruit about 20 minutes. The Guacamole is the other way round: cold water only. Cold water leaves meat and potato a little firmer than hot, sometimes with a spoonful of liquid at the bottom. Some are hot water only, and REI’s 0 minutes for instant mash doesn’t carry over to ours: the Mashed Potato, the Porcini Mushroom Risotto and the broths.

Dry, from the pouch

With waterServing suggestion

Stir into the corners, close the zip and give it a second stir halfway, as with any pouch. The clock applies to a pouch exactly as it does to a jar: from the moment the water goes in.

From our range

Lentil & Vegetable StewLarge

Takes 490 ml of water; with cold water, about 30 minutes.

€16.90€84.50/kgHear from us before the shop opensSee the stew