Image
Chris Lintz of Lintz Estate winery, near Martinborough in the Wairarapa, squints into a refractometer, in 1992. Growers can check if grapes are ripe for harvesting by squeezing a drop or two of grape juice onto this instrument. Light is refracted (bent) by the juice to a degree proportional to the amount of sugar in the juice.
Te whakamahi i tēnei tūemi
Alexander Turnbull Library, Dominion Post Collection (PA-Group-00685)
Reference: EP/1992/2065a/10
by Ray Pigney
Permission of the Alexander Turnbull Library, National Library of New Zealand, Te Puna Mātauranga o Aotearoa, must be obtained before any re-use of this image.