In vegetable fermentations (e.g., sauerkraut or pickles), which conditions most favor the development of “floaters” (pieces that buoy up instead of remaining submerged)?

Introduction:
Floaters are defective pieces that rise to the brine surface during lactic fermentations. This question checks practical knowledge of processing factors that trap gas in plant tissues and promote buoyancy—important for quality, safety, and brine coverage control.

Given Data / Assumptions:

• CO2 generated by heterofermentative lactic acid bacteria can inflate tissues if not released.
• Salt concentration influences osmosis, gas production patterns, and tissue firmness.
• Thicker skins impede gas diffusion.

Concept / Approach:
Excessively high initial salt can harden tissues osmotically and slow normal early fermentation, leading to uneven gas evolution and retention. Thick skins (or poorly shredded/trimmed surfaces) physically limit gas escape. Together, these factors trap CO2, reduce effective brine coverage, and create floaters prone to yeast/mold spoilage at the surface.

Step-by-Step Solution:
Identify gas source: microbial CO2 early in fermentation. Relate high salt to tissue firmness and gas retention problems. Recognize thick skins as diffusion barriers for dissolved gases. Select the combined condition “both (a) and (b).”

Verification / Alternative check:
Process troubleshooting guides link excessive salt and poor trimming to floating defects and surface spoilage risk.

Why Other Options Are Wrong:

• High salt only / Thick skin only: Each contributes, but floaters are most favored when both factors operate.
• None of these: Contradicted by plant tissue behavior and brining physics.

Common Pitfalls:
Ignoring proper shredding, packing, and weights to keep material submerged under brine.

Final Answer:
both (a) and (b) favor the development of floaters.