The plants sprang back to life after a day with water. I've let them grow for a few more days, but things aren't really moving much at this point due to mutual shading and limited vertical space.
I pulled a few leaves and had a few tastes.
Still alive and no unfortunate bathroom incidents, so whatever colonized the tray must have been benign or easy to wash off.
Leaves averaged 18cm long and 12cm wide at the widest, 5 grams fresh weight. I estimate about 200 grams of leaves could be harvested; far less than I hoped but not bad considering their stress history. I'll collect them all soon and note the total edible mass.
- Sap was thin, milky only near the base of the leaf. It had a fairly strong 'bitter lettuce' smell, which is typical for freshly-picked leaves.
- The leaves were slightly limp for a number of reasons (water stress, heat stress, competition, etc.) but still managed to stay horizontal with minimal drooping.
- Several had small brown 'burn' spots on the edges where the leaves had rested against the nutrient-encrusted clay puffs, but otherwise every leaf was perfect.
- The flavor at the outside was mild, sweet but with enough bitter undertone to avoid blandness. Texture was much like the outer wrap leaves of head lettuce; I happen to like those so I thought the result was good.
- Flavor at the stem was stronger, but still sweet. Usually I find leaf lettuce to be overpoweringly bitter at the stem base, so that was a nice surprise. All of the stem and vein structures were crisp.
- No 'aftertaste' or unpleasant flavor undertones after eating.
Overall I am surprised at how tasty the results were. I managed to mess up the process in several different ways but the plants survived and even thrived.
The rest of the family is suspicious, so I might be the only one eating fresh salad for the next day or two. We'll see.
Not much to add beyond what was in my image post, other than that you should definitely try this at home. Even the mistakes seem to work out well; can't wait to see how a well-designed crop will turn out next time.