I found an article that compares white bread made with yogurt whey to the same formula made with a sourdough starter.
Valorization of Acid Whey to Produce Sourdough Bread Starter
Contrary to what the title might make you expect they aren't making a sourdough starter, they are making bread.
I had to look up "valorization".
Valorization is the process of increasing, enhancing, or realizing the economic, social, or functional value of something, such as turning waste into products, upgrading commodities, or maximizing the societal impact of research. It involves transforming low-value materials into higher-value resources (waste valorization) or validating the worth of ideas and knowledge.
Their primary interest is reducing waste.
Abstract
Acid whey, a by-product of Greek yogurt and acid-coagulated cheese, poses environmental challenges due to high biochemical and chemical oxygen demand. It also contains lactic acid bacteria (LAB) with the potential to enhance fermentation. Using acid whey in breadmaking addresses waste management while creating value-added products. To evaluate acid whey as a starter in bread production and compare its performance with commercial sourdough and white bread. Acid whey from skim milk yogurt was used to replace 50% of the water in the dough. Three breads were prepared: white bread (WB), acid whey bread (AWB), and commercial sourdough bread (CSB). Physical, chemical, microbial, and textural properties were measured. Consumer acceptability was assessed using a nine-point hedonic scale with 81 participants. Data were analyzed using ANOVA and paired t-tests (p < 0.05). AWB showed greater loaf volume (1550 ± 20.4 cm3) than WB (1375 ± 20.4 cm3, p < 0.05) and similar aeration to CSB (p = 0.97). Its pH (5.17 ± 0.03) was lower than WB (6.07 ± 0.12, p < 0.05), indicating stronger fermentation. AWB displayed lighter crust color and delayed mold growth compared to WB. Sensory tests showed higher scores for AWB in flavor, aroma, color, texture, and overall acceptability (p < 0.001). Notably, 76.5% of participants preferred AWB over CSB for purchase. Acid whey is a viable alternative to commercial sourdough starters, producing bread with favorable qualities while reducing dairy industry waste, offering benefits for sustainable food production.
I question many of their choices but this work could make a good starting point for playing with yogurt whey as a souring agent.
Gary
You deserve the Medal of Valorization for posting this, Gary! :)
I regularly use the whey from my homemade yogurt, especially for white breads. My yogurt ferments for 16-17 hours so it is more acidic than most storebought varieties. I too question some of their choices, especially this one:
Skim milk yogurt? Yuk. And 50% of water is a huge amount. That's double what I've arrived at as a max amount to use.
Have you observed the pH of the dough dropping over time with the added whey? I'm wondering if the LAB in yogurt will process what they find in dough.
I agree with your yuk. I guess they chose skim to avoid the added fat confusing the comparison.
I think they would have done better to add a bit of yeast to the sourdough to match the acidity of the whey bread.
Gary
I haven't measured the PH so can't answer that one.
I did not like the taste of breads made with 50% whey. Apparently yogurt LABs are different than sourdough ones.
One of my fave white breads uses ~20% (of H2O) whey and 15% (of H2O) CLAS. Ferment time and temp are critical.