3 easy questions about adding flax and chia seeds to sourdough.

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3 questions about adding seed inclusions...

Soak in water first? How long?

Would like to add chia and flax.. how much total seed (grams) for 450 grams flour?

I make a really great spelt SD biga loaf with chia and flaxseed. They work really well together. Both need soaking. I do a boiling water soak for the flaxseed and a cold soak for the chia. I leave both overnight before mixing the loaf the next day. I would do 20g of unsoaked flax with 5g of chia for 400g total flour. Wouldn't probably go over a total of 30g.

You need to soak the seeds in an excess of water so they become fully hydrated but then work out how much of the water is fully absorbed and how much remains and then subtract the remainder from your total loaf water. You also subtract the unsoaked  seeds weight from your total flour and work out loaf hydration based on the remaining flour. Have a look at this post to do the maths

It's really worth the hassle.  Very nice flavour combination chia and flax and loads of soluble fibre in the final loaf.