How to Prepare Sunchokes to Reduce Gas and Bloating
I hold what I believe is Canada’s largest collection of Jerusalem artichokes, also known as sunchokes. I grow them, eat them, sell them, and talk about them to anyone who will listen. And the number one question I get is always the same: how do I eat sunchokes without the gas?
It’s a fair question. Sunchokes have earned a reputation, and a nickname to go with it. But with a few simple habits, you can enjoy this nutty, sweet, wonderfully versatile tuber without clearing the room. Here’s what I’ve learned from years of growing and eating them, along with what the research says.
The Fartichoke Dinner Party
I was at a seed swap with tons of Jerusalem artichokes for sale when a man walked up to my table. He looked genuinely shocked that I was selling them. “Fartichokes!” he said, and he seemed a little triggered just looking at them.
I asked him if he had ever tried them and whether he liked them. He told me his wife had made them for a dinner party with many guests. Everyone ate lots of them because they were so good. Then the sunchokes’ notorious gases turned into the real party poopers, and everyone had to leave. Some guests said they would never come back for dinner again.
That story makes me laugh every time, but it also shows exactly what not to do. Nobody at that party knew to go slow.
Why Sunchokes Cause Gas
Sunchokes store their energy as inulin instead of starch. Inulin is a type of fibre that your body can’t digest on its own. It passes into your large intestine, where your gut bacteria feast on it, and that fermentation produces gas.
Here’s the good news. That same fermentation is what makes sunchokes so good for your gut. Inulin is a prebiotic, meaning it feeds the beneficial bacteria that live in your digestive system. The goal isn’t to avoid inulin completely. It’s to give your gut time to adjust.
How Much Inulin Is Too Much?
The dinner party problem comes down to dose. Sunchokes are one of the richest sources of inulin there is. Professor Bob Rastall, a food biotechnology expert at the University of Reading in England, told Modern Farmer that sunchokes can be as much as 30 percent inulin by fresh weight, while volunteers in his nutrition trials regularly handle up to 20 grams of inulin a day without significant problems. An average tuber weighs about 3 ounces, which works out to as much as 25 grams of inulin in a single sunchoke.
Clinical research tells a similar story. In a controlled study of healthy adults, doses of up to 10 grams of inulin a day were well tolerated, and the most common complaints were flatulence followed by bloating. That’s why one raw sunchoke is my limit, and why a big bowl of them at a dinner party is asking for trouble.
My Best Methods for Eating Sunchokes With Less Gas
Start Small and Build Up
This is the most important tip I can give you. Eat just a little at a time when you’re easing into sunchoke season. I know it’s hard to stop at a few bites when they taste this good, but after a week or so, I find I can gradually eat more. Your gut bacteria adapt to what you feed them, so patience pays off. Once your body has adjusted, you may even find yourself eating sunchokes every day.
This isn’t just my experience. Professor Rastall recommends eating small amounts on a regular basis rather than avoiding inulin altogether. Over time, your gut adapts: the beneficial bacteria multiply, the gas producing bacteria decline, and eventually you can eat sunchokes without discomfort.
If you’re cooking for guests who have never had sunchokes, serve them as a side dish rather than the main event. Learn from the fartichoke dinner party.
Boil, Drain and Smash
My favourite way to reduce the gas is to boil the sunchokes first, then drain them well. Next, I put them in a frying pan, smash them flat with the bottom of a cup, and let them dry out and crisp up.
Research on inulin extracted from sunchokes found it becomes more soluble as temperature rises, so boiling and pouring off the cooking water may carry some of it away. The smash and fry step then gives you crispy edges and a creamy centre, so you don’t lose any flavour.
To take this method even further, add lemon juice to the pot. Acid breaks inulin down into fructose, a sugar your body can absorb, through a process called acid hydrolysis. Food scientist Harold McGee recommends boiling sliced sunchokes in plenty of water for about 15 minutes with 1 tablespoon of lemon juice per quart. Writer Kristan Lawson tested boiling 1/4 inch slices for 15 minutes in just enough lemon juice to cover them, and reported no gas at all after a heaping bowl. The tradeoff is flavour: lemon boiled sunchokes taste sweeter and lose some of their artichoke flavour.
Ferment Them
Fermenting is one of the most effective methods of all. When you lacto ferment sunchokes, the good bacteria in the jar feed on the inulin for you, so the gas bubbles out in the jar instead of in your belly. According to Professor Rastall, both lemon boiling and fermenting leave enough inulin behind for prebiotic benefits, but not enough to cause gas, even with a generous serving. Fermented sunchokes keep their crunch and nutty flavour, with a pleasant tang.
Go Easy on Raw Sunchokes
I love eating sunchokes raw with a sprinkle of salt or a good dip. They’re crunchy and refreshing, a bit like a water chestnut. But raw sunchokes keep all their inulin, so when I eat them raw, I only eat one.
A Note for Sensitive Stomachs
If you have irritable bowel syndrome or follow a low FODMAP diet, take extra care. Sunchokes are high in fructans and rank among the highest FODMAP vegetables, so many people on a low FODMAP plan skip them during the elimination phase or test only tiny tastes. Fermented or lemon boiled sunchokes may be the gentlest place to start.
Does Harvest Time Make a Difference?
Personally, I’ve never noticed a difference in gas from one harvest to the next. But the research shows that a sunchoke’s chemistry does change depending on when you dig it and how you store it.
Studies show that inulin chain length is highest around flowering time and drops significantly by the final tuber harvest. Tubers harvested late in the season also had lower inulin content. Researchers in Lithuania found that tubers dug in late autumn, or overwintered in the soil and dug in spring, contain more of the shorter fibre chains.
Storage matters too. During storage, an enzyme gradually breaks inulin down, lowering inulin content and raising the natural sugars, while freezing best slows these changes. One study found that tubers kept in cold storage for up to 8 months steadily lost inulin and average chain length. If you want to keep your harvest going all winter, here’s my guide on how to store Jerusalem artichokes for winter.
No study has measured gas directly, so I can’t promise any of these will make a difference for you. But less total inulin may explain why many people find late season tubers sweeter and easier on the stomach. If you want to experiment, try:
- Harvesting after a few hard frosts in late autumn
- Leaving some tubers in the ground over winter and digging them in spring
- Storing your tubers in the fridge for a few weeks before eating them
Do Some Varieties Cause Less Gas?
Research hasn’t ranked sunchoke varieties by how much gas they cause, but it has tested several for inulin. A Hungarian study comparing five cultivars singled out ‘Ceglédi’ for its outstanding inulin content. An Italian trial found that ‘Violette de Rennes’ had the longest inulin chains of the clones tested.
I’m happy to say Violette de Rennes is now part of my collection. It’s a beautiful variety, and I’m looking forward to sharing it with you.
Why Sunchokes Are Worth a Little Gas
Food Security in Your Backyard
Sunchokes are one of the easiest crops you will ever grow. Once they’re in the ground, you have a large supply of food sitting under the soil in your backyard, ready whenever you need it. They’re the plant you can count on to always provide some nutrition. I wrote more about this in why Jerusalem artichokes are the perfect heirloom crop for rising grocery prices.
Delicious and Versatile
I love their nutty, sweet flavour, and they can be prepared in so many different ways. Roast them, smash them, slice them raw, or puree them into soup. You can even dry them and grind them into flour, or ferment them.
Good for Your Gut and Your Health
In a placebo controlled human trial published in the British Journal of Nutrition, volunteers who drank juice containing sunchoke inulin had significantly higher levels of bifidobacteria, a beneficial gut bacteria, than the placebo group. A Thai study of 90 healthy adults concluded that fresh sunchokes could serve as a prebiotic in place of imported commercial supplements.
They’re nutritious too. According to USDA data, one cup of raw sliced sunchokes contains about 110 calories, 3 grams of protein and almost no fat. That same cup provides 28 percent of the daily value for iron, 18 percent for potassium, 12 percent for phosphorus and 11 percent for copper, making sunchokes a great plant based source of iron.
A Plant for Changing Times
Preserving sunchokes matters to me because they are such an important food to have in the garden. They can handle drought, cold weather and all kinds of growing situations. As I believe we go deeper into the Grand Solar Minimum, I feel this is exactly the type of plant that will handle longer winters and short, hot summers.
They’re beautiful too. Sunchokes are members of the sunflower family, and their cheerful yellow blooms look right at home in a flower bed. They can be planted almost anywhere and work wonderfully in front yards.
Where to Start
If you’re nervous after hearing about the fartichoke dinner party, I recommend starting with Clearwater. It’s my earliest variety, so you’ll be enjoying your own harvest sooner. Violette de Rennes is another wonderful choice.
Honestly, though, I recommend them all. Every variety in my collection is amazing in its own way.
You can find my sunchoke tubers for planting at Garden Faerie Botanicals. Start small, eat slowly, and welcome one of the most generous plants you’ll ever grow into your garden.