Yes indeed it's true that sourdough bread is low FODMAP per Monash University! I know there are many people who aren't fond of gluten free bread, so it's a happy day when they learn they can eat sourdough on the low FODMAP diet. Of course, if you have gluten sensitivity or celiac, you'll need to continue to avoid bread made from wheat.
Why is sourdough bread low FODMAP? Great question! It's thought that the wild yeast and bacteria produced in the sourdough fermentation process actually consumes some of the FODMAPs, thus reducing them to a level that's low enough to qualify them as low FODMAP.
But did you know that not all bread labeled sourdough is actually made using the true sourdough fermentation process? Many sourdough breads are just regular bread with a sour flavoring added to them, so it's important to read the label to know what you're getting. Some jokingly refer to these fake sourdough breads as "sourfaux".
Below are some tricks for identifying true, low FODMAP sourdough bread. Please note that we can't ever be 100% certain regarding FODMAP status unless something has been officially lab tested. It's not possible to eat only certified foods at this time since so many foods haven't been certified, so we have to use our best judgement in many cases.
When looking for a true sourdough bread, look for one that has a small number of ingredients in it. Some will list a "sourdough starter". This is a good sign. Typically there is only flour, water, and salt in true sourdough bread. FYI sometimes flour is written on the label as "Unbleached Enriched Flour (Wheat Flour, Malted Barley Flour, Niacin, Reduced Iron, Thiamine Mononitrate, Riboflavin, Folic Acid)".
Avoid any breads with high FODMAP ingredients like high fructose corn syrup or honey (often no sweeteners are added to sourdough).
The key is to look for a sourdough that is naturally, slow leavened for at least 1-2 days. It is this process that consumes enough of the FODMAPs to make the bread low in FODMAPs. The leavening time may be written on the package, on their website, or if buying from a bakery, you can ask them directly. Sometimes the addition of yeast can mean that it was not slow leavened because yeast can be added to accelerate the process.
I have found that natural markets, like Whole Foods, PCC, Trader Joe's and local bakeries tend to be the best sources for true sourdough bread.
Let's take a look at a few ingredient labels of some breads labeled "sourdough."
This one is from a bread that is labeled "sliced sourdough."
In this case, vinegar is added to make the sour taste, and yeast is added to speed up the process. Looks like "sourfaux" to me.
This one is Nashoba Brook Bakery's sourdough bread.
As you can see, it has minimal ingredients and contains natural sourdough starter, so that's a good sign. Then I checked Nashoba Bakery's website, and it states that they use a slow leavening process with no yeast added, so I'd bet on this being a low FODMAP option.
The label below is from Berlin Natural Bakery's Old Fashioned Sourdough Spelt bread. Only three ingredients are listed. Checking their website, it says that their sourdough starter is fermented for at least 24 hours, so this is also a good choice.
Of course, you can always try making your own sourdough bread if you can't find a suitable one locally. And as with all foods, listen to your body and experiment with small portions to start with. Everyone has unique tolerances-- no one can guarantee what's going to work from person to person.
Happy sourdough hunting!
Do you have a brand of sourdough that you love or have you made your own? Share in the comments if so!