Self Raising Flour Recipe: Ratio & Grams Guide

Fancy a batch of scones but only have plain flour? The fix is simple: mix 2 teaspoons of baking powder per 150g of plain flour, a ratio confirmed by UK baking blog Baking with Granny, and this guide covers conversions from 100g to 500g plus storage tips.

Raising agent: Baking powder · Ratio: 2 tsp baking powder per 150g plain flour · Shelf life: Store in airtight container up to 3 months · Common use: Cakes, scones, pancakes

Four key facts about making self‑raising flour at home, one pattern: most sources converge on a 2‑teaspoon‑per‑150g baseline, but exact teaspoon amounts can vary by brand.

How do you make 200g self‑raising flour?

• Add 2.5 teaspoons of baking powder to 200g plain flour, according to Baking with Granny (UK baking blog).
• Sift together to ensure even distribution of the leavening agent.

Step‑by‑step method

Weigh out 200g of plain flour. Using a dry measuring spoon, add 2.5 level teaspoons of baking powder. Pass the mixture through a fine‑mesh sieve into a bowl, then whisk to aerate. This takes less than two minutes.

Ratio for 200g plain flour

The 200g conversion follows the same logic as the base ratio: 2 tsp per 150g scales up to 2.5 tsp for 200g. A separate calculation from Top With Cinnamon (home baking site) uses 1 tsp per 75g, which would give about 2.7 tsp for 200g — close enough for most home baking.

The pattern: the 2.5 tsp ratio for 200g is a direct scaling from the base ratio, and sifting ensures even distribution.

How to make 250g of self‑raising flour?

• Use 3 teaspoons of baking powder per 250g plain flour (Baking with Granny (UK baking blog)).
• Alternatively, 250g plain flour plus 15g baking powder (The Guardian (British newspaper)).

Exact measurements for 250g

Three level teaspoons of baking powder yield about 12g, which is slightly lower than the 15g proposed by The Guardian. The difference is small enough that both methods work for cakes and scones.

Adjusting for larger batches

When scaling up, multiply the baking powder by weight rather than volume to maintain consistency. The gram‑based rule — 5g baking powder per 100g plain flour — also works: 250g flour plus 12.5g baking powder.

How to make 100 grams of self‑raising flour?

• Mix 2 teaspoons of baking powder into 100g plain flour (Top With Cinnamon (home baking site)).
• Another source recommends 1 level teaspoon (≈4g) of baking powder for 100g (Sandhya’s Kitchen (cookery blog)).

Small batch ratio

The discrepancy between 2 tsp and 1 tsp for 100g is exactly the kind of variation flagged by The Guardian. For most home baking, either will produce a decent rise — but if you prefer a lighter crumb, go with the higher amount.

Substituting salt

Add ¼ teaspoon of salt per 100g if you want to mimic the salt content in commercial self‑raising flour. This is optional but recommended for flavour.

How do you make a cup of self‑rising flour?

• 1 cup (120g) plain flour plus 2 teaspoons baking powder.
• If using a US‑style cup (150g), still use 2 teaspoons — the extra weight doesn’t need more leavening for most recipes (Baking with Granny (UK baking blog)).

Cup measurement conversion

Because cup sizes vary between 120g and 150g, it’s safer to weigh your flour. If you must use a cup, stick to 2 level teaspoons of baking powder regardless of cup weight.

Standard US vs UK cup sizes

A US legal cup is 240ml, which holds about 120g of plain flour. UK cups are often 250ml, holding roughly 150g. The ratio works for both as long as you don’t overpack the cup.

How to make 500 grams of self‑raising flour?

• Combine 6.75 teaspoons of baking powder with 500g plain flour (Baking with Granny (UK baking blog)).
• That’s about 27g of baking powder, or roughly 5.4% by weight.

Bulk batch ratio

For a large batch, measure by weight: 26–28g of baking powder per 500g plain flour. Sift in three lots to ensure the leavening agent is evenly distributed.

Storage tips

Keep your homemade self‑raising flour in an airtight container in a cool, dark cupboard. Use within three months for best results. Label the container with the date so you know when it was made. For more easy lunch ideas, check out our Easy Lunch Ideas NZ.

Self‑raising flour recipe ratio

• Standard ratio: 2 tsp baking powder per 150g plain flour (Baking with Granny (UK baking blog)).
• Gram‑based: 5g baking powder per 100g flour (Desert Island Dishes (cookery site)).
• Chef’s variation: 150g plain flour plus 1½ tsp baking powder (recommended by baker Ebuehi, via The Guardian (British newspaper)).

Standard ratio

The 2‑tsp‑per‑150g rule is the most widely cited, but The Guardian notes that professional bakers sometimes use slightly less baking powder for a slower, more even rise.

Why sifting matters

Sifting aerates the flour and distributes the baking powder evenly — otherwise you risk pockets of bitter leavener in your finished bake. A fine‑mesh sieve does the job in 20 seconds.

The implication: the 2‑tsp‑per‑150g ratio is reliable, but professional bakers may adjust for a slower rise.

Step‑by‑step method

1. Weigh your plain flour into a bowl.
2. Add the appropriate amount of baking powder (see table above).
3. Sift the mixture through a fine‑mesh sieve directly into another bowl.
4. Whisk briefly to combine — do not overwork.
5. Use immediately or store in an airtight container.

The whole process takes under three minutes. No special equipment needed. For a quick dessert, try our Viral Fruit Ice Cream.

The key takeaway: sifting is non-negotiable for even distribution.

Quotes from the experts

“I recommend 150g of plain flour with two teaspoons of baking powder — that’s the closest you’ll get to commercial self‑raising flour.”

— Nigella Lawson, cookery writer (cited by The Guardian (British newspaper))

“Self‑raising flour is simply plain flour with baking powder and salt added. Making it at home gives you control over freshness and additives.”

— BBC Good Food editorial team (food magazine)

These two perspectives bookend the conversation: Nigella’s well‑tested ratio and BBC Good Food’s emphasis on ingredient control.

Frequently asked questions

The bottom line: making self‑raising flour at home is quick and gives you control over freshness.