Is Homemade Oat Milk Actually Cheaper?
Oat milk has become a household staple, but branded cartons can cost $4–$6 per litre at most supermarkets. The good news is that oat milk is one of the simplest plant-based milks to make at home — all you need is rolled oats, cold water, and something to strain it through. The question is whether the savings are real enough to make the habit stick.
The core ingredient cost is surprisingly low. A kilogram of budget rolled oats typically costs $1.50–$3.00, and a standard batch of homemade oat milk uses roughly 80–120 grams of oats per litre of finished milk. That puts the oat cost alone at $0.15–$0.35 per litre — a fraction of what you pay at the checkout.
The main variables to keep in mind:
- Oat quality: Quick oats and instant oats release more starch, making the milk slimy. Stick to old-fashioned rolled oats for the best texture.
- Straining method: A fine-mesh cheesecloth or a reusable nut milk bag gives the cleanest result. A cheap cheesecloth costs a few dollars and lasts many batches, so its per-litre cost is negligible once amortised.
- Water temperature: Always blend with cold water and avoid over-blending — heat and friction activate the starch and make the milk gummy, especially noticeable when you heat it for coffee.
- Yield: Expect roughly one litre of strained milk per 100 g of oats plus about one litre of water.
Homemade oat milk typically comes in between $0.20 and $0.50 per litre once equipment is factored in. Compared to a $4.50 carton, that is a saving of around 85–95%. Even if your oats are on the expensive side, homemade is almost always the budget winner.
One caveat worth noting: commercial oat milks are often fortified with calcium, vitamin D, and vitamin B12. If you rely on oat milk as a nutritional source for these nutrients, consider a separate supplement or choose fortified varieties for some of your intake.
Frequently Asked Questions
How much oats do I need per litre of homemade oat milk?
A standard ratio is about 80–120 grams of rolled oats per litre of finished milk. Starting with 1 cup (roughly 90 g) of oats blended with 1 litre of cold water, then strained, typically yields around 900–1000 ml of oat milk. Using more oats gives a creamier result but increases the ingredient cost slightly.
Why does my homemade oat milk turn slimy or gloopy?
Sliminess is caused by starch being released from the oats. The two most common culprits are using warm or hot water and over-blending. Keep your water cold (even add ice), blend for no more than 30–45 seconds, and avoid quick-cook or instant oats, which have a higher surface area and release starch faster than old-fashioned rolled oats.
Does homemade oat milk froth for coffee?
It can, but it requires a bit of technique. Cold, freshly made homemade oat milk froths reasonably well with a handheld frother. However, it tends to separate or turn gloopy when heated in a steam wand. Adding a small pinch of salt and a teaspoon of neutral oil (like sunflower) per litre can improve emulsification and make it behave more like a barista-style carton oat milk.
How long does homemade oat milk keep in the fridge?
Homemade oat milk lasts 4–5 days in a sealed container in the refrigerator. It contains no preservatives or stabilisers, so it may separate — simply shake or stir before use. If it smells sour or develops an off taste before the 5-day mark, discard it.
Is homemade oat milk as nutritious as store-bought?
Homemade oat milk naturally contains small amounts of carbohydrates, a little protein, and some fibre from the oats. However, commercial oat milks are typically fortified with calcium, vitamin D, vitamin B12, and sometimes riboflavin. Homemade versions lack these added nutrients unless you supplement them separately. If you rely on oat milk for these micronutrients, check your overall diet to ensure you are getting them from other sources.