Actually very easy

Oat milk

The beliefPlant milk is assumed to be impossible at home, and slimy and undrinkable if attempted.

The truthOats and water. It only turns slimy from warm water and long blending — avoid both and it takes ten minutes.

10 minutes

How to make it

What you need

100 g rolled oats
1 litre of iced water
A pinch of salt
Fine cloth or a nut-milk bag

How the engine read this list (3 lines)

100 g	Rolled oats	oat
1000 g	Iced water	water
0 g	Salt	salt

An empty weight means that line could not be turned into grams — either the amount is open ("to taste") or the ingredient has no record here. Neither enters the sum as zero; they do not enter it at all.

Rinse the oats once in cold water and drain. This removes some of the loose surface starch and makes the result noticeably thinner.
Put the oats, iced water and salt in the blender. The ice matters: friction heat is what releases the beta-glucan.
Blend for no more than 30 to 40 seconds. The longer it runs the slimier it gets: under-blended is thin, over-blended is jelly.
Strain through fine cloth but do not squeeze: wringing the bag pushes the pulp’s starch into the milk and produces exactly the texture you were avoiding.
Bottle it and refrigerate. It settles, so shake before each use.

Why it works

The whole problem of oat milk is one molecule: beta-glucan. Oat’s soluble fibre swells in water and builds a viscous gel — good news for health, since this is the compound shown to lower cholesterol, and bad news for texture. That gel forms under two conditions, heat and mechanical energy: friction from the blender plus a long blend releases the beta-glucan and the milk turns slimy. The remedy is direct — use iced water and blend no longer than 30 to 40 seconds. The second issue is starch, which partly gelatinises from the blender’s heat and thickens further when cooked; that is why home-made oat milk curdles in coffee. Straining through fine cloth leaves most of the gelling particles behind.

The rough sum

1100 grams going in

389 kcal in total

100% of the mass has figures behind it. This is the sum of what GOES IN rather than of what comes out. Wherever something evaporates, drains or ferments the two differ: a kilo of milk is 150 g of cheese.

Diets it qualifies for

Gluten-free · with care Vegan Vegetarian Lactose-free

Storage & shelf life

How long it keeps

Fridge, in a sealed bottle: 3–4 days
Room temperature: 2 hours
Freezer: 1 month, though it separates on thawing
Settled: Normal — shake it

Home-made oat milk keeps a tenth as long as the carton, and the reason is technological: shop milk is UHT-sterilised and filled aseptically, while yours is raw. Starch and sugar make an excellent medium for bacteria, so it starts souring after three days. It needs shaking every time because there is no emulsifier — the white layer at the bottom is starch, not spoilage. Do not try to extend its life by boiling it: heat releases the beta-glucan and the milk turns to jelly.

When to bin it A sour smell, bubbles or lumps that will not shake out mean it goes. Oat milk sours unmistakably as it turns — if you are unsure, it has already gone.

History

Where it comes from

Plant milks are not a new invention: almond milk was common in medieval Europe and the Middle East, because fasting periods barred animal milk and, in a world without refrigeration, almond milk kept far longer than cow’s. Anatolia used almond and poppy-seed milks in desserts too. Oat milk, by contrast, came out of a Swedish university study on lactose intolerance in the 1990s — one of the rare foods that arrived from a laboratory rather than a kitchen. Its dominance today is technical as well: oats use less water than almonds or soy, and behave better in coffee.

The knack

For coffee, add a pinch of salt and a teaspoon of neutral oil: the fat builds an emulsion and reduces curdling.
Keep the pulp: it goes into biscuits, köfte mixtures and granola, and still holds most of the fibre.
Remember it thickens when cooked: for a pudding or a sauce, halve the starch the recipe calls for.

The pantry