I asked AI a pertinent question relating to the binding method of Lievito Madre:
What are the mechanisms which explain how carbon dioxide acts as a bacteriostatic?
Carbon dioxide (CO₂) acts as a bacteriostatic agent through several mechanisms: [1]
- Displacement of Oxygen: CO₂ can displace oxygen in the environment, creating an anaerobic condition that inhibits the growth of aerobic bacteria [1].
- Intracellular Acidification: CO₂ can diffuse into bacterial cells and form carbonic acid, leading to a drop in intracellular pH, which can disrupt cellular processes [1].
- Membrane Function Disruption: CO₂ affects the function of biological membranes, preventing cell division, absorption, or transport of substrates [2].
These mechanisms collectively contribute to the bacteriostatic effect of CO₂, slowing down the growth and reproduction of bacteria [1].
1. A Review of Effects of Carbon Dioxide on Microbial Growth and Food Quality
2. Role of Carbon Dioxide in the Regulation of Adaptive Proliferation in Bacteria
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Further to that information:
Massari says the continued release of CO2 that occurs during both the “free” and Piemontese methods augments the production of acetic acid which is very undesirable in the finished product.
Massari says that binding retards fermentation such that sugars within the dough are utilised more slowly, and if not bound sugars are consumed in half the time.
From my own observation the binding clearly favours the production of lactic acid and may even promote its production during the overnight fermentation.
Fascinating question! If dough undergoing alcoholic and heterolactic fermentation is confined in such a way that it can't expand, the carbon dioxide produced by the yeast and lactic acid bacteria would indeed accumulate in the liquid phase. This could lead to the liquid phase becoming supersaturated with carbon dioxide, which means it would contain more carbon dioxide than it could normally hold at atmospheric pressure.
In practical terms, this could create a pressurized environment within the dough. If the pressure becomes too high, it might lead to the dough bursting out of its confined space, or it might impact the texture and properties of the dough.
I gave your exact prompt to ChatGPT (free edition), and after its lengthy response, added this:
Me
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The context here is is the preparation of the starter for Panettone bread, so more common bread preparation considerations may not apply. In this case, the low hydration starter is sometimes bound with string into a tight package. Without making assumptions about the exact nature of the fermentation (e.g., heterolactic, etc) would you change your remarks in view of knowing this context? Respond concisely.
ChatGPT
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In the context of a tightly bound low-hydration starter for Panettone, the liquid phase may still become supersaturated with CO₂ due to the constrained environment, even without expansion. However, the low hydration reduces the water available to dissolve CO₂, potentially limiting the degree of supersaturation compared to higher-hydration doughs. The tightly bound structure might also influence CO₂ distribution and retention differently than in free-form dough.
TomP
What do you deduce from that TomP?
Darned if I know. It just seemed like an interesting bit of followup. I had been thinking of gas escaping from the exposed surface between turns of binding twine, and an effect of less water leading to less dissolved gas hadn't occurred to me. I've never even made panettone, but sometimes I wonder if there isn't something I could learn about more conventional sourdoughs so I've just been following these panettone threads.