It took a bit of fiddling to get this one going. All the recipes and internet research said that it would get bubbly overnight. So bubbly, that the jar shouldn’t be more than 2/3 filled.
I did several different versions that all failed, until I finally broke out the proofing box. The problem had been the too cold kitchen. With the nice and toasty temperatures, the potato yeast spawned from candied, mashed potato within a few hours. It had full strength after two days. Victory at last! I only thought it fitting to name the spawn Victoria.
To make a potato yeast, you need:
- 2 medium potatoes, peeled and cubed
- 400g water
- 150g wholegrain flour (I used wheat)
- 1 Tbsp sugar
Add the potato pieces, the water and the sugar to a small saucepan and bring it to a boil. Cook the potato until it’s soft, about 15 minutes. Mash them up with a fork right in the water or squeeze them through a potato ricer back into the sugar water. Mix well and let cool to about body temperature.
Add the flour to the mix, stir well and fill everything into a jar so it’s about half full. The yeast needs a lot of room to bubble once it’s active. Place a lid on top and keep the jar in a warm place (26°C / 78F) for about 2 days. You need to stir the mix a few times a day, because the potato tends to oxidize. If you don’t stir, you’ll end up with a black layer on top.
Once the potato yeast is bubbly and risen, you can place it in the fridge and use it as a replacement for industrial yeast.
2 Tbsp potato yeast = 1 sachet (7g) dried yeast (2 1/4 tsp if you measure from bulk packs)
You need to feed your potato yeast once a week to keep it active.
1/2 c potato yeast
1/2 c water
1/2 c wholegrain flour (I used wheat)
1/2 Tbsp sugar
Mix everything and keep it on the counter until it’s bubbly and active if you want to bake the same day. If you don’t have any baking projects lined up, keep the yeast on the counter for an hour, then move it into the fridge.
I have developed the habit of replacing what I used up immediately and only discard and feed if I haven’t used the potato yeast in more than a week. So if I take 2 Tbsp yeast, I give 1 Tbsp water, 1 heaped Tbsp flour and a pinch of sugar right back and stir it in.
All my discards end up in the monster mash and get used up eventually.