ISO 5703-1979 pdf free.Equipment for vine cultivation and wine making — Grape presses — Methods of test.
The pressing of the press during tests shall be comparedwith that of the reference press.
By means of a distribution duct，pass the grapes to bepressed simultaneously into two weighing hoppers situatedabove the entrance to the reference press and press under-going tests.
The pressing programme of the press undergoing tests shallbe the programme recommended by the constructor.
An operating sheet (or check list) for the press (see annexes and C) shall be completed for each test. On this sheetshall be entered the properties of the grapes used : varietyofvine，degree of cleanliness,maturity,duration ofdraining,duration offermenting, temperature of thegrapes, etc.
The minimum test sample of sound,whole grapes,storedor processed in the mechanized emptying tank (to bedivided between the press to be tested and the standardpress) should be sufficient to filltwo presses homo-geneously.
Before pressing,subject the sample to static draining inthis vat for a maximum period of 30 min; do not begindraining until the vat has been completely filled. For thecontinuous acting press，draining of grapes should besufficient to ensure a normal working.
Thepressing programme for the standard press shallcomprise sufficient screwing operations maintained by anautomatic regulating device,to obtain a gross outputapproximately equal to that of the refercnce press.
This is when the grapes are pressed and have not previouslyundergone any mechanical action before arriving at thepress.
The minimum test sample of sound grapes (to be dividedbetween the press to be tested and the standard press)should be sufficient to fill the two presses homogeneously.This is when crushed grapes，regardless of whether theyhave been destalked or not, are pressed after having undergone fermentation until draining. This is also the pressingof crushed and destalked grapes which have been soakedand heated before any fermentation (hot soaking). Theyare partially drained before pressing.When removing the marc, put into sealed plastic bags threesamples each weighing 5 kg and which are as homogeneousas possible, stabilize them with mustard essence and analysethem very quickly.
ln order to guarantee that the marc sample is homogeneous,take the following precautions :Discontinuous press : take three samples when the marc isbeing evacuated, one at the beginning of the evacuation, thesecond halfway through and the third towards the end ofevacuation.
Continuous-acting press : take the three samples over theentire width of the cake of marc,i.e. from the peripheryto the centre of the cake; repeat the operation three timeswith two equal intervals during the time taken as a basisfor the test.ISO 5703 pdf download.