# How much potato starch to used instead of mashed potato in bread?

Molly Yeh recently said she substitutes potato flour (starch?) for mashed potato in making bread when she doesn't have time to make the mashed. As I regularly make Refrigerator Potato Bread (J Beard), this is a great tip. But I can't find (from Molly on fb or her website) what ratio of potato starch to use for 1 cup mashed.

• Posted by: Nancy
• June 9, 2023
• 2673 views
• 7 Comments

### 7 Comments

HalfPint June 9, 2023
Hope this helps a little:

From the National Institute of Health, "In general terms fresh potatoes contain ~20% dry matter (DM) of which 60–80% is starch, with 70–80% of this starch as amylopectin"

I would take 20% of the total weight of the mashed potatoes, then multiple by 60% (on the conservative end), which would give you a conservative estimate of how much potato starch (by weight ) to use. Then you could probably adjust as needed.

HalfPint June 9, 2023
Part 2:

USDA lists 1 cup of mashed potatoes as ~210g, so using the estimates above, 20% x 210g x60% = 25.2g starch in 1 cup of mashed potatoes

2 TB potato starch is 17.4g. This leads to:

2TBx25.2g/17.4g = 2.889TB or 3TB of potato starch, to start

HalfPint June 9, 2023
On the high end, assuming 80% starch content, you would use 4TB potato starch.

Nancy June 9, 2023
@HalfPint - many thanks for both the theory and the calculations!
I’ll use these measures the next time I make the potato bread. Will report on the results (and hope James Beard is not rolling in his grave)…

KLS June 12, 2023
Nancy, I think he's always rolling about something LOL

HalfPint June 16, 2023
Let us know when you make this next time. I am curious to see how close the calculations are, if at all. You might have to increase the flour and/or liquids to compensate for the bulk mass of mashed potatoes.

Nancy June 18, 2023
@HalfPint - well, I made my old bread recipe with potato starch instead of mashed as the only replacement.
It tasted good but yes was a little different in texture than the original version - in fact, a lighter crumb.
I think I will make it this way a couple more times and then decide if I’ll put this version in regular rotation

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