A press is a batch
The destemmer has a rate and the press does not. Four tons a load on a two and a half hour cycle averages 1.6 tons an hour, and that average is only true if the press never waits for fruit and never sits half full. Twenty-four tons is six cycles if it all goes in together; split into two lots of twelve, it is three cycles each and still six. Split it into five lots and it is ten cycles, because a 4.8 ton lot needs two loads and the second one is only 0.8 tons full.
That rounding is the single biggest schedule risk on a crush pad, and it is created entirely at the whiteboard rather than by any machine. The page prints the bulked figure beside the separated one so the cost of the decision is visible before the day starts rather than after it.
The slower machine sets the day
Six tons an hour through the destemmer against 1.6 tons an hour averaged through one press means the press binds, badly. The whole day runs at 1.6 tons an hour whatever the destemmer can do, and 24 tons over six picking hours takes 15 hours to clear — five hours past a ten hour shift.
Add a second press and the average becomes 3.2 tons an hour, and the day comes down to 7.5 hours. Make the destemmer 25 percent faster instead and nothing at all changes, because the destemmer was never the constraint. This is the most useful thing the page does: it stops money going into the machine that is already waiting.
Reds are a different day. The fruit goes to tank and the press happens a fortnight later, so the destemmer is the only thing on the critical path and 24 tons at six an hour is four hours of machine time. The press cycles still have to happen, but not today, which is why the page moves them out of the binding calculation when the route is set to red.
Backlog is arrival minus service
Twenty-four tons over six picking hours is four tons an hour landing on the pad. If the pad processes 1.6, it falls behind by 2.4 tons an hour, and by the time the pickers stop there are 14.4 tons standing in bins — 29 half-ton bins. Clearing that at 1.6 tons an hour is another nine hours.
If the pad processes 4.5 tons an hour instead, nothing ever stacks up and the day finishes when the picking does. The turning point is exactly where the service rate meets the arrival rate, and either side of it the day looks completely different, which is why the peak backlog is worth watching as much as the finish time. A pad that just keeps up on the average will still bury itself the moment a gondola arrives early.
What is not in the number
Sorting. Moving hoses. Waiting on a forklift. Sanitising between lots. The clean-down, which on most pads is an hour nobody schedules. Breakdowns, which happen at harvest more than at any other time because everything is running at once and nothing has been serviced since April. The finish time here is the machinery arithmetic alone and a real day runs longer than it, usually by a third.
And the thing worth naming plainly rather than modelling: a crush pad during harvest is where wineries hurt people. Augers, gondolas, forklifts, wet concrete, long shifts, and a fermenting cellar full of carbon dioxide next door. Nothing on this page is a procedure for any of that.
Questions people ask
How many tons can a crush pad process in a day?
Whatever the slower of the two machines does, which is usually the press. Six tons an hour through a destemmer against one press doing four tons on a two and a half hour cycle gives a pad that runs at 1.6 tons an hour, so a ten hour shift clears 16 tons and not 60. The destemmer rating on its own tells you almost nothing about the day.
Why does keeping lots separate cost so much time?
Because a part load is still a whole press cycle. Twenty-four tons in one lot is six cycles at four tons a load. The same tonnage split into five lots is ten cycles, since each 4.8 ton lot needs two loads and the second is barely a fifth full. Four extra cycles at two and a half hours each is ten hours of press time created by a decision on a whiteboard.
How much fruit will be waiting on the pad?
Arrival rate minus processing rate, times the hours the pickers keep going. Twenty-four tons over six hours arrives at four tons an hour; a pad processing 1.6 falls behind by 2.4 an hour and has 14.4 tons standing in bins when picking stops. That is 29 half-ton bins, and it takes another nine hours to clear.
Should I buy a second press or a faster destemmer?
The page answers it from your own numbers rather than in general, and with the defaults it is not close: a second press takes the day from 15 hours to 7.5, while a destemmer 25 percent faster changes nothing at all because the destemmer was already waiting. The rule underneath is that spending on the station that is not binding buys nothing, and the binding station changes with the fruit and the route.
Does this include cleaning and sorting?
No. It is machinery arithmetic only — destemming and pressing. Sorting, hose moves, waiting on a forklift, sanitising between lots and the clean-down at the end are all real hours and none of them are counted. A pad that runs a third longer than this figure is normal rather than slow.