I read Remembrance of Things Past twenty years ago so don’t actually remember the famous scene in which the narrator bites into a madeleine cake and is transported back to his youth. Your garden variety English nerd will point out (or Wikipedia) that the scene is part of Proust’s exploration of voluntary vs. involuntary memory. Briefly voluntary memory is where you try to remember something. For instance how to spell a shell shaped small French cake. Involuntary memory is where the memory is thrust upon you often because of outside interference.
Yesterday as I picked pinto beans and cursed Mexican bean beetles, I was startled out of my invective by a decrepit truck coming around the corner. What rolled into view was a dangerously maintained ice-cream truck. I could hear a faint melody, muffled by rattles and squeaks. Inside a sweaty man negotiated the corner while arguing into his cell phone. He didn’t see any kids, though I’m not sure he was looking. I looked around the neighborhood and realized an ice cream truck on a week day had no chance. Kids are at camp because parents are at work. That summer’s over; we don’t do that anymore.
The ice cream man could tell I wasn’t interested: I was harvesting. One of the indigent boarders has offered to harvest produce for money. I’m hesitant to let him because sometimes you have to make judgment calls about ripeness. Tomatoes are the perfect example.
A tomato will “ripen” when picked as long as there is the tiniest fraction of red showing. That is, it will turn red, soft and get sweeter and less acidic. In nature ripening tells animals that it is time to eat the fruit, so the plant delays ripening until the seeds are ready. A complicated series of signals leads to tomato ripening. The main signal is the gas ethylene. In grocery stores ethylene is applied to mature, unripe tomatoes to get them to redden and soften. The tomatoes must be mature – the seeds must be ready -- or ethylene won’t work. Maturation is signaled by an epigenetic mechanism: a temporary change is made to the DNA so that ripening can proceed (Zhong et al., Nat. Biotech., 2013).
Those grocery store “ripened” tomatoes aren’t really that good though. They were shipped green then treated with ethylene, and they weren’t bred for taste. The tomatoes I grow are supposed to be tasty, so I want to pick them at the peak of ripeness. This matters, even crappy grocery store tomatoes taste better if ripened on the vine (Arias et al., J. of Food Sci., 2000).
When you leave the tomato on the plant it acts as a “sink” for sugars and other nutrients. The plant produces sugars in the leaves and they head through the plant’s veins, the phloem, to the sinks – the fruit. The longer the fruit is on the plant the more goodness it gets. So I delay picking until full on ripeness. Can I trust the boarders to do that? I don’t think so. They’re fine with green beans, but not tomatoes.
When I get a tomato just right, I’ll stand in the garden and bite right in. The juice runs down my chin and that’s when I have my madeleine moment: all the summers past in a single moment and I forget that the kids are inside playing Minecraft.