Spring Onion (green part)

Why spring onion (green part) is rated low

The green tops of spring onions are low, and they are one of the most useful low foods on the whole diet, because they carry onion flavour without the part of the plant that causes the trouble. The green leaf and the pale bulb are effectively two different foods here: no FODMAP subgroup is recorded for the greens, while the bulb is a different matter entirely. This rating is estimated from what the green tops are made of rather than measured from a weighed portion, and the single rung on the ladder, "Any typical portion", reads low. So a generous scattering of greens through a stir fry, a soup or a salad is fine, as long as the knife stays above the point where the green loosens into white.

What changes your risk

• Green, not white This is the lever that matters most. Cut where the leaf stops being green and starts being pale and tightly wrapped, and keep only the green. The white bulb is not a smaller version of the green top, it is the part you are avoiding, and tossing a couple of bulbs into the pan undoes the whole point.
• Infused oil for the base flavour Fructans are water-soluble and do not dissolve into oil, so garlic-infused or onion-infused oil carries the flavour with none of the fructans. The catch is that no solid pieces may be left sitting in the oil, so strain them out or buy an oil with nothing floating in it, and use the oil as the flavour base with the greens added at the end.
• Labels where the bulb is hiding Onion powder, garlic powder, onion salt, vegetable and chicken stock cubes, gravy granules, most spice blends, marinades and ready-made sauces are the same problem written in small type. A dish seasoned with spring onion greens and finished with a stock cube is not a low FODMAP dish.
• Serving size and the whole meal Low here means low at "Any typical portion", and the greens genuinely are a background ingredient, so this is rarely the limiting factor. The rating is still per serving rather than per meal, so keep an eye on the total load of everything else on the plate.
• Dried and powdered onion products Drying removes water and concentrates what is left, and dried onion flakes or powder are made from the whole bulb, never from the greens. There is no dried equivalent of this food, so use the fresh leaf.

What else works

For the same fresh onion note, chives are the closest match and are excellent raw over eggs or potatoes, the green leaves of leek do the same job in a braise or soup, and a pinch of asafoetida in hot oil gives a surprisingly convincing savoury allium background. Garlic-infused oil is the workhorse for the base of almost any dish. What is genuinely not a swap, whatever a recipe or a label suggests: the white bulb of the spring onion, onion of any colour including shallot, the leek bulb, garlic itself, and any product built from them such as onion powder, onion salt, stock cubes and most seasoning blends. If a recipe insists on chopped onion as its foundation, replace the foundation with infused oil rather than looking for a gentler onion, because there is not one.

How to keep it low

Buy bunches with firm, bright green tops and no sliminess at the tips, and store them upright in a jar with a little water in the fridge, or wrapped loosely in a damp cloth. Cut the whole bunch at the colour change in one go, bag the greens for the week, and set the bulbs aside for stock you will not drink or throw them out, so a tired evening does not turn into a reflex chop of the wrong end. Sliced greens freeze well in a flat bag and go straight into a hot pan from frozen. Add them late, since they lose their bite with long cooking. Eating out, ask for spring onion garnish rather than sauteed onion, and ask what the stock is, because that is where the bulb usually turns up.

Common questions

is the green part of spring onion low fodmap

Yes. The green tops are rated low at "Any typical portion", while the white bulb is not. The rating is estimated from what the green leaf is made of rather than from a weighed test serving.

how much spring onion greens can i use

The ladder gives one rung, "Any typical portion", and it is low, so a normal scattering through a dish is fine. There is no tested amount above that, so use them as a generous seasoning rather than as the bulk of a meal.

can i eat spring onion greens on the elimination phase

Yes, and they are one of the main reasons the elimination phase does not have to taste flat. Use the greens, keep the pale bulb out, and build the base flavour on garlic-infused oil.

what can i use instead of onion for flavour

Garlic-infused or onion-infused oil with no solid pieces left in it, plus spring onion greens, leek leaves, chives, or a pinch of asafoetida. Onion powder, onion salt and stock cubes are not substitutes, they are the same ingredient under a different name.