Ten bags. That is the working size of a microlot in James Hoffmann's The World Atlas of Coffee: typically ten export sacks of 60 or 69 kg or fewer, from one farm or producer group, which puts the whole lot under about 700 kg of green coffee. A microlot is a small batch that has been kept physically separate from the rest of a harvest, from the mill onward, and sold under its own name at its own price. That separateness is the entire definition. The word tells you the coffee was isolated. It does not tell you why, and it does not tell you it was worth isolating.
The reasons for keeping a batch apart are usually one of four: a specific plot on the farm, a single variety, one harvest day's picking, or a processing experiment the producer wants to sell on its own terms. Keeping it apart is real work. The lot needs its own drying bed and its own marked sacks through the dry mill, plus paperwork that follows it across an ocean. That cost is why microlots carry a premium, and why the premium can be honest: a producer who separates a good plot and gets paid more for it has a direct reason to farm that plot better next year.
The term sits at the far end of a naming ladder that keeps escalating. Maxwell Colonna-Dashwood's The Coffee Dictionary traces the sequence from single origin, which can legally mean an entire country, down through single farm, single-variety lot, microlot, and now nano lot. Each step claims tighter traceability than the one before. None of the steps is policed. There is no auditor weighing bags and revoking the word from anyone who applies it to twenty tonnes.
What a microlot will not do is guarantee a better cup, because separateness is a provenance claim and not a quality claim, and a separately dried failed experiment is still a failed experiment. Taste one because you want to know what a single plot or a single decision tastes like on its own. That is a real and specific pleasure. Just read the rest of the label with the same scepticism you brought before the word appeared, because the wider lesson of coffee labelling is that single origin means less than you think.