How to make potato flour at home

I’ve recently started to experiment with gluten-free flours and flours that are easier to digest, including potato flour.

The problem is that the shop-bought potato flours could be a bit pricey and also seems to have a fairly short shelf life.

Making potato flour at home is actually not that difficult. It not only saves you money, but you can also make the only amount you need without having any flour going off.

It’s a great money saving project and you can easily turn your leftover mashed potatoes or boiled potatoes into potato flour.

Why use potato flour in baking?

Potato flour gives any bake a lighter texture, whether it’s bread, cake or biscuits. You can swap part of regular gluten flour with potato flour (or potato starch) to give your yeasted bread a higher rise and lighter crumb. Potato flour, similarly to lupin flour, is also naturally gluten free, which means you can safely use it in gluten-free baking.

Making your own potato flour at home is also a good way of using up potatoes, instead of freezing them.

To make potato flour at home, we need to first dry the potatoes and then grind them.

What type of potatoes to use

You can use any type of potatoes, but I normally go for large, starchy types of potatoes. Not only that they are easier to peel and slice, but they also have more starch than new or baby potatoes.

Preparing your potatoes

Wash the potatoes properly under water using a potato brush or scrub them with a sponge.
Next, slice the potatoes as thinly as you possibly can, much thinner than when you are making au gratin potatoes. The thinner they are the quicker they will try. You can just use a sharp knife for this, potato peeler (if it’s big enough) or mandoline slicer or other food processors. well and peel the outer skin.

Next step is to place the potato slices on a baking tray (or large tray) lined with a greaseproof paper. When I first started to dry my fruit and vegetables I would use a newspaper, but I wouldn’t recommend doing this as you could get the newspaper ink or colour on your potatoes.

If you don’t have a greaseproof or baking parchment, don’t use any. I’d stay clear of using absorbable papers, unless you know the paper fibers won’t stick to the potatoes as they are drying.

At this stage, you can also par boil the potatoes to prevent them from browning. All you need to do is to bring a large saucepan to boil and boil the potatoes for 1-2 minutes, depending on how thinly you’ve sliced them. You only want them to go through the boil, but not to actually boil them.

Next job is to work out how to dry your potatoes as quickly as you can.

How to dry your potatoes

Oven

This is not the most cost-effective way to dry your potatoes, but if you for example have your oven hot/warm from just finishing your food, you can easily put the trays with potatoes in and leave the oven switched on at about 125° F/52° C or the lowest setting. Or leave the oven switched of and just add the baking trays in.

Depending on how thick your potatoes are, this method can take about 6-8 hrs. If you need to leave your house or can’t watch the oven, it’s O.K to switch off the oven and leave the potatoes in and just switch it back on when you return. You can just dry the potatoes in short burst of heat.

Dehydrator

If you have a dehydrator, then just place your potatoes in your dehydrator’s trays and follow your manufacturer’s instructions for temperature and the length of time it will take to dry your potatoes. As a rule of thumb, I would usually set the temperature for 125° F/52° C and it takes about 8 to 10 hours to get the potatoes dry, depending on how thick they are.

Sun

If you have a safe part of the garden where you know no animal (like a cat or a dog) will come to visit, you can easily dry your potatoes on a direct sun. Unlike drying herbs, you can place the baking trays with sliced potatoes directly on the sun.

The sun will quickly dry the potatoes, so make sure you check your potatoes slices at regular intervals – anything from 30-60 minute and turn them round. To make them dry quicker, when turning them place them slightly off the spot they have been drying previously.

On a direct hot sun in the summer, this process should take about 4 hrs.

Hot room

This is very cost-effective way to dry your potatoes indoors as it doesn’t cost anything, but it’s also the longest way to dry your potatoes. First of all find a spot in your house or a flat that’s naturally hot. It could be in the boiler room, next to the hot water tank, hot spot on the floor where you have the hot water pipe going under, a hot spot in the attic or a glass conservatory.

This method can take 3-4 days depending on the amount of sun/heat you have available. Make sure you turn your potatoes to help them to dry quicker.

Radiator

In the winter it might be better to dry your potatoes on radiators, especially if you already have the heating on. Depending on how often (and for how long) you have your heating on, this method can take anything up to 2 days. Make sure you still turn your potatoes slices over, as this will speed up the drying process.

How to tell when your potato slices are dry

They will reduce in size and will be very light and dry to touch. When you try to crush them with your fingers, they should crumble.

If you are not too sure, whether they are ready or not, you could run a text batch through your grinder or food processor. If they potatoes don’t resemble a fine flour and look more like a dry mashed potatoes, they are not ready yet. You can always put the text potato batch back on the tray, spread it lightly and carry on drying.

How to grind your potato flour

Any kind of blender, food processor or grinder will do a good job at processing the potatoes into flour. You could even crush the potatoes under a rolling pin (like crushing biscuits in a bag), but it would take long time to get the flour as fine as you’d probably like it to be.

I usually use a sieve to separate the large parts of potatoes and either run them through the grinder or food processor again or keep them for other uses (like making mashed potatoes).

Storing your potato flour

I keep mine in an airtight container (usually plastic). I also find that the flour lasts longer when the potatoes are slightly overdried. This way there is no moisture, which can start generating bacteria growth or start developing mould in the flour.

If your potato flour feels slightly damp when you process it, just leave it to dry more in the oven or somewhere hot before storing it.

Other ways of making potato flour

Over the years I’ve also experimented with different ways of making potato flour. You can make potato flour from pre-cooked potatoes, blanched or mashed potatoes, pretty much any type of potatoes you have at hand.

Potato flour from mashed potatoes

Peel your potatoes and chop into smaller chunks to save time on boiling. Boil your potatoes (without any salt) until they are done and drain the water.

Mash the potatoes with a suitable potato masher or a fork and spread on the baking tray in a very fine layer (lined with parchment paper), use a dehydrator or dry the potato mash naturally. Move around the mashed potatoes to make sure they are drying and not catching mould from the bottom of the tray.

Potato flour from grated potatoes

Instead of fine slices, you can also grate the potatoes. When you do that, I usually use the larger grater because it’s quicker (but you can use the smaller one too).

The next step is to remove as much water as you possibly can by squeezing it in a colander or a sieve or even using a clean cotton tea towel. You’ll be surprised how much water comes out!

After that, just space out the grated potatoes on a tray and dry using one of the methods above.

Potato recipes

• Irish Potato Cakes >>
• Leak & Potato County Soup >>
• Traditional Potato Bread >>
• Baked potatoes (in crock pot) >>

Troubleshooting your potato flour recipe & frequently asked questions