Solved my starter issue
My liquid white flour starter gets gradually weaker over time, although was created from rye flour. My regimen was to feed my culture a couple of times a week and refrigerate after the starter had ripened on the bench. The culture is 125% hydration and is fed with white bread flour.
The culture was initially strong with good rising power. After about three weeks it becomes weak and has a reduced ability to give a good rise and volume to the loaves. I have to occasionally freshen the starter with stone-ground rye to return its vitality and power.
The problem is that I did not notice the weakened state of my culture until I elaborated the starter to make the levain. The ensuing bake yielded a loaf with poor rise and volume.
I stumbled across Jeffrey Hamelman’s ISO videos. In the Vermont sourdough episode, Hamelman revealed that the culture he maintains at home is a stiff rye sourdough. He gave the formula as 10-gram stiff rye sourdough, 20-gram rye flour and 17-gram water. I calculated the baker's percent to be 50% stiff rye sourdough, 100% rye flour and 85% water. He feeds it every morning and has been doing so for 40 years, without alteration.
I was immediately interested in trying out a stiff rye starter in the hope it would solve my issue.
Furthermore, in the Deli Rye Bread episode, Hamelman again used his stiff rye sourdough to make the Deli Rye Bread. He also included some liquid starter. He does not maintain two starters, only the stiff rye sourdough. When he needs a liquid white flour levain, he first converts some stiff sourdough to a liquid starter over two feeds.
I was convinced that this would provide me with a consistently lively starter that I could rely upon.
I fired up my Excel spreadsheet and made the calculation: Liquid stater to a stiff rye sourdough to match Hamelman's.
The process is in two stages:
1. Convert the liquid starter to a stiff starter. This is only needed to be performed once. To 56 gram of my 125% hydration liquid starter, I added 68-gram of stone-ground rye flour. Cover and leave on the bench until next morning.
2. Commence Hamelman's regimen. Mix 10-gram stiff rye culture with 17-gram water. Mix in 20-gram stone-ground rye flour.
I repeat the feeding once a day first thing every morning.
Using the stiff rye starter
Many of the sourdough formulae I bake with requires a liquid levain of 125% hydration.
Again with my spreadsheet, I calculated that I could easily create the liquid levain over two feedings. At the time of feeding the stiff starter in the morning, I use the leftover starter to make a small amount of 125% liquid starter: 37-gram stiff rye starter, 20-gram water and 9-gram bread flour. Then leave on the bench until about 5 pm that day. I then elaborate the starter to make the levain for the next day. The levain requirements for a Vermont sourdough is to pre-ferment 15% of the overall flour. Bread flour 100%, water 125% and mature liquid starter 10%. (I put the levain in a proofing box overnight at 24C). The levain is ripe when needed at 7 am the next morning.
The elaborated levain was very bubbly and appeared lively, more so that I have ever seen.
I noticed at the end of the bulk fermentation, that the dough had a nice feel of lightness, and had good structure.
It was easy to pre-shape and shape into an oblong. I placed the dough into a banneton to proof. After 2 hours I checked the dough and determined it was ready for the oven, half an hour earlier than the usual proofing time.
The dough was easy to score after being inverted onto a wooden peel. It did not flatten out on the peel and held it's structure.
I baked the loaf on a stone in a pre-steamed oven, and steam for the first 10 minutes after loading. Finished in a drying oven.
The oven spring was much better than before. The ear and gringe opened up nicely.
This will now be my new sourdough starter regimen.