YW ratio for Levain or Bread Dough

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DanAyo on 28 Feb 2022 at 07:41

As of late my baking endeavors have focused on breads without sour flavors. I also like naturally leavened breads instead of Commercial Yeast most of the time.

With this in mind I have a few technical question -

  1. How much YW is used in either a Levain or bread dough for a given ferment time?
  2. Is a Levain (pre-ferment) the normal procedure or is it mixed straight into the Final Dough?
  3. If a Levain is scheduled to ferment overnight (12 hr), what percentage by weight of flour should be YW?

I get the idea that most TFL bakers “ball park” the amount of YW, but I’d like to know if there is a correlation similar to SD Starter.

I would suggest you get to the group on FB  “Artisan Bread Baking with wild yeas and water”

 

When I use YW, I use it to build a levain rather than go straight into the final dough. I think there's quite a bit of guesswork involved since one sample of YW could be very different from the next depending on how it's maintained, whereas with sourdough starters, you can (sort of) compare apples to apples based on hydration, seed amount, etc. to generalize how a given percentage of starter will behave. With YW, it's all liquid, so I have less of a sense of just how much yeast is in there.

The nice thing is that YW will keep in your fridge for a very long time without fuss or loss of leavening power (at least IMO), unlike sourdough starters that will get too acidic, get funky, and lose steam. Because of that, I just take out my YW from the fridge when I need it, and use that water to build the levain (no other water added). And just monitor the levain's growth just like any other levain.

I'm excited to hear about your coming experiments with YW, DanAyo. If you or someone else is able to come up with some generalized observations, please share!

Here is the formula and my notes for Hamelman's Swiss Farmhouse Bread. You can see that 47.7% of the flour is pre-fermented over two builds using yeast water in the first build.

Swiss Farmhouse bread.jpg

IMPORTANT NOTE FROM GAVIN: Make sure the raisins are organic without any trace of chemicals or oil additives. I failed when using Sunbeam raisins as they had 0.5% sunflower oil and hadn't declared any chemicals – no rise or activity due to something in them that kills the yeasts. I looked at the Macro “organic” raisins and found that they had a 0.5% oil coating.  So, pending delivery of true organic raisins, I cut up some kumquats from next doors tree, put them in a jar with a couple of teaspoons of pure honey and water. Day 4 and I had bubbly active yeast water. Success! I shall update these notes after my next organic raisin attempt. I have since made the raisin water successfully (picture below)

Hamelman’s Instructions:

1. RAISIN SOAK: 5 to 6 days before the bake, soak the raisins in the water. Cover and leave at warm room temperature (24°-27°C is ideal). White mould normally begins to cover the surface of the raisins. an indication that the liquid is ready. Occasionally. however. no mould is visible. If the juice is bubbly with a sweet and tangy aroma. the natural yeasts are most likely active in the juice and the dough process can begin.

UPDATE: My successful process adopted Debra Wink’s research (microbiologist): Proofing box set at 25°C. I used organic raisins and left for 5 days. Setup was a 500ml jar with a water airlock. After 5 days, there was no sign of mould. Despite lots of activity from day 3, I waited until day 5 so that the Saccharomyces population reached its maximum, while other yeasts drop like flies. The lactic acid bacteria drop to their lowest numbers after about five days (less than 10/ml), which explains the absence of acidity in the bread. 

2. FIRST BUILD: Drain the raisins. collecting the juice. Discard spent raisins. Scale the required amount of juice, add the flour, and mix to incorporate. Cover and leave at room temperature for 6 to 8 hours. until well risen. I put it in my proofing box for 8 hours.

3. SECOND BUILD: Add the second build water to the first build and lightly break up the contents of the first build. Add the second build flours and mix until incorporated. Cover and leave to ripen for 12 to 14 hours until fully domed. My second build was ready after 12 hours in the proofing box. As always, the goal is for the preferment to be domed and fully risen at the time of final mixing; make whatever adjustments give that result and all will be well.

4. MIXING: Add all the ingredients to the mixing bowl except the walnuts and raisins. In a spiral mixer, mix on first speed for 3 minutes in order to incorporate the ingredients, If necessary, correct the hydration by adding water or flour In small amounts. Finish mixing on second speed for 3 minutes, to moderate gluten development. Mix the walnuts and raisins together and add to the dough. Mix on first speed only until they are evenly incorporated. Desired dough temperature: 24°C.

5. BULK FERMENTATION: 2 ½ to 3 hours.

6. FOLDING: Fold the dough halfway through the bulk fermentation.

7. DIVIDING AND SHAPING: Divide the dough into 680-gram pieces (or larger, as desired). Preshape into rounds. When sufficiently relaxed, shape into round or oval loaves, or place into loaf pans. Cover the loaves to prevent a crust from forming during the final fermentation.

8. FINAL FERMENTATION: 1 ½  to 2 hours at 24°-25°C.

 

9. BAKING: Place the risen loaves on the loading conveyor or peel. Slash as desired. Presteam the oven, load the bread, and steam again. Bake in a 232°C oven. After 15 minutes, lower the oven to 221°C to avoid excess darkening due to the raisins. Loaves scaled at 680 grams will bake in approximately 36 minutes.

Swiss Farmhouse bread crumb.jpg

 

Dan,

I use my YW directly from the refrigerator and build levains using 125% hydration and 30% PFF.  At 76 deg F, they usually take 8-12 hours to get nice and bubbly.  I would agree with the 2-part build mentioned by Gavin.  Either that or add a pinch of ADY to the Final Mix.

Good luck!

Troy  

I use a preferment as normal procedure to make things more reliable. If necessary a double preferment (as per the CB) to make it even more reliable and as per the RonRay links. Or develop the preferment in a transparent container to assess development and when it has increased in volume and shows good alveoli (approx 8 hours) store in fridge for use at a later date.

It is hard to visually asses a YW culture to know how potent it is. Fizziness; time since feeding and sediment all are clues, but have had some occasions when they've let me down and this is why I rely on the preferment.

My preferred preferment is stiff at 65% hydration (as per the CB) and from 30-45% PFF.

As I study the replies to this post there seems to be a consistency of large percentages of PFF. In a sourdough levain the PFF is typically much less, because there is an issue of introducing too much degraded (acidic) dough into the mix.

Are higher PFF in YW allowed because the acids (lack of relative % of LAB) in the culture are less destructive during the levain builds? If this is the case it seems that since there is a large PFF and the flour in the levain is wet for a long period of time that the dough should be more extensible - Nice to handle.

I will be doing some more work here...

If you followed the post I had about yogurty levains from YW, one thing Jon, Caroline, and I did was develop a levain from the bottom sediment to see if it was active.  Mine had a very acetic aroma, so I decided to maintain it as a SD starter.  I've been feeding it 1:1:1 with bread flour and fermenting it at 70-72 deg F.  Unfortunately, it has lost any aroma that's sour.  Has a mild fruity smell maybe.  In many ways, it's almost "odorless".  I'm going to keep feeding it and see if it adapts to the food source and develops some aromas.

Here's the interesting thing.  Feeding at 1:1:1, it triples in volume in 5 hours at 72 deg F.  It then hangs out there for a few hours, and then recedes maybe 15-20% where it stays.  I've been feeding it on a 12-hour cycle.  I measured the pH last night to see if it was maintaining any acidity or if any LAB's that were present had died off.  pH was 3.84.  It is a very stable and fluffy starter even 4-5 hours past ripe.

EDIT:  I don't have a dough pH meter.  I have one of the standard bulb pH probes.  Not sure it's 100% accurate measuring a 100% hydration levain, but I'm fairly confident it's well into the acidic pH range.  In a few days, I'll compare this to the brand new RYW I made.  Will get starting and finishing pH's of the starter and a RYW levain build.

Can do!  Work travel for a couple days, so it will be an overnight build on Thursday.  I'll do both the new RYW, the RYW sludge starter, and my normal 120% hydration white starter.  All three will have been refrigerated for 3-5 days, so should be a reasonable comparison.

Got home a little late last night, so didn't have time to do all three starters but here is the new RYW.  This is a brand new YW created last weekend, and this is the first levain I've built with it.  I thought it was looking pretty potent based the fizzing, but after a 4-5 days in the refrigerator, it was slow building.  I would definitely plan for 2 builds with this YW, and I may have to give it some more fermentation time.

However, I did get some good pH data for this build.  The RYW was taken directly from the refrigerator and mixed 1:1 with bread flour.  The RYW was drawn from the top of the jar using a turkey baster without disturbing the sediment at the bottom.  pH was taken immediately after mixing and then placed into fermentation at 77 deg F.  pH at the start  of fermentation was 4.94.  As mentioned, the fermentation progressed slow, but it was nearly doubled after just over 15 hours.  The pH at that point was 3.99, so it dropped roughly 1 pH unit.

 

I’m surprised at the drop in pH of the levain as it ferments, I wasn’t expecting that.  What acid do you think is being produced to cause such a drop in pH?  You mentioned earlier that you wondered if your RYW had become inoculated with LAB and if they were the cause of the acidity you smell and taste in your RYW breads.

I’d really be curious to hear what other bakers find if they can measure the pH of their yeast water levains.

Benny

I'd like to hear from others too. 

This levain was also noticeably acid and vinegary.  But...  This is a new RYW.  With new organic raisins that do not have sunflower or palm oil.  Prepared in a jar that was thoroughly washed and then sterilized with boiling water.  If this also has LAB's, they had to come in with the raisins.  Any chance it's a bag of bread flour with high LAB content?  Got me guessing...

You will see a pH drop from fermentation as CO2 is generated and bicarbonate alkalinity is consumed.  Not sure it would take you much past pH 4.4 though (methyl red end point) under normal atmospheric conditions.  However, in a sealed jar with elevated CO2 partial pressure in the head space, it might drive you into the free mineral acid range. 

 

This is fascinating. YW generating such a large drop in pH?! Very interesting.

Two ideas: can you try the same, but with no yeast of any kind (just flour and water, left for the same time), and with a tiny pinch of commercial yeast? Yeast do generate some acid as well, just much less than LABs. So perhaps if it needed a very long time to double maybe they had enough time to really bring a substantial acidity... Or if your flour has a large number of LABs or other acid producing bacteria you'll get a drop of pH even without any yeast.

Both of these can be used in a bread later (one as a small amount of autolysed flour, as long as it doesn't start smelling weird by the end of the experiment from spontaneous fermentation, the other is a normal preferment), so shouldn't be just a waste of flour.

I can certainly do both of those, and I’ll add water/flour only as a control.  I may do YW with a different white flour as well just to round out the experiment.  Should be able to do this sometime tomorrow.  Going to pull the RYW out of the refrigerator now to let it perk up and hopefully reduce the time to maturity for the levain.

This week a raisin YW was made. It steadily bubbles, although not furiously. The goal is to make TX Farmer’s SD Sandwich bread in hopes that the flavor is not sour. NOTE - it is my experience that if the fermentation times and temp are not adhered to the bread can become a little too sour. But not super sour.

A two stage levain build was used.
The first stage took a long time to mature.
The second stage rose quickly and quadrupled. 

9:15 pH of RYW = 3.67
19:30 pH of RYW = 3.64 (added 1/4 water to replace what was used for first levain build. 

First Build
9:15 50/50 RYW/Strong Flour pH 4.71
19:30 2.75x Rise pH 4.65

Second Build
10:20 Added flour to reduce hydration to 54% pH 5.05
06:00 Levain had over-matured (forgot to take pH :(  ) Took pH after it was put into cold milk - 5.08
The mature Levain produced a gorgeous cell structure and quadrupled. It stuck to the glove at the top the glass. My SD Levains never produce that cell structure.

The dough was quite different from one made from a SD starter. It developed gluten much quicker. The dough seemed to be more shiny. It was elastic and showed signs of plasticity (I think that is a correct description).

How I wished the pH was taken on the matured Levain!

Question -
Since it is commonly accepted that YW produce non-sour breads, how do we explain a pH reading of 3.6 taken in the culture jar?
Although the RYW shows a low pH, the dough does not.

That‘S great looking pH data Dan, I’d say the RYW cultures have low pH from the acids in the fruit.  I wonder what the pH would be if you just soak raisins for a number of hours before any fermentation starts or blend them to get their acids outs of the dried fruit?

  1. Microbes, both yeast and LAB, drift around and land on Wheat, and Grapes (which become raisins) and every other thing exposed to nature. 
  2. BUT, wheat berries produce yeast and LAB
  3. AND, grapes and other such fruit produce predominantly yeast

Why is this so?
Could it be that the YW solution stays too acidic to allow LAB to grow and reproduce?
Are all YW solutions very acidic?
We are taught that LAB do not tolerate low pH, buy yeast are not affected by the acidity. 

“ Could it be that the YW solution stays too acidic to allow LAB to grow and reproduce?

Are all YW solutions very acidic?
We are taught that LAB do not tolerate low pH, buy yeast are not affected by the acidity. ”

It certainly seems like that might be the case.  Despite the LAB existing on the exterior of the fruit, once the acids from the fruit acidify the water perhaps the LAB never really get a good chance to take hold the way they do in sourdough starters in which the pH rises quite a bit when fresh flour is added to them.  So when a starter is feed the higher pH allows the LAB to replicate and populate the stater and then their activity decreases as the pH drops below 3.8.

So to answer your earlier question, because the starting pH of the RYW is so low the LAB never really take hold.  So a levain made with yeast water will make a bread that isn’t particularly acidic.

“ I’d say the RYW cultures have low pH from the acids in the fruit.”

When we consider the following, it does seem to make sense.
9:15 pH of RYW = 3.67
19:30 pH of RYW = 3.64 (added 1/4 water to replace what was used for first levain build

After +10hr the pH only dropped 0.03.

This is great data Dan!  Your RYW pH is very close to what I have and the the RYW/flour blend is also close.  Good to see that consistency.  

Curious…. What kind of aroma did you get from the mature levain?

Benny, have you ever thought to measure the pH of the crumb?

Watched a video where this was done and it was eye opening the difference between sourdough and non sourdough breads. Can dig it up if you're interested.

I'd also be interested in seeing data about YW pH changes as well! Time to get a meter, but can be expensive in these parts.

-Jon

I am noticing that YW leavened doughs are much stronger than typical SD leavened doughs when both are fermented in similar ways. The dough is strong and resilient, even after long fermentation. I attribute that to the lack of acids.

Tomorrow a TX Farmer Sandwich Loaf will be baked with a RYW. This is a first for this particular bread. Hoping for the complex flavor of a naturally leavened dough, and the long keeping qualities, without any sour flavor notes.

My RYW dough is strong but neither elastic or extensible. I will be surprised if you get a soft crumb or a sour note. The second build and a higher proofing temp seems to kick it into another higher gear. Mine was ready in a few hours  instead of the 12 hours in the recipe. I will be interested to see how it rolls out and then recovers during the final proof. If it is successful you could call it LA Fisher Sandwich loaf;-)