Field Heat, Issue 01, The first mile. Web edition.

In the spring of 2018 I stood in a buyer’s yard in Vashi and watched a man in a vest open one of our trucks. The thermometer on the door read four degrees. The grapes inside had been at four degrees for nine hours, exactly as we had promised. He lifted a box, pressed two berries between his fingers and set the whole pallet aside. The berries had gone soft at the stem, and the stems had turned from green to brown.

Nothing had gone wrong on our watch. The truck was cold, the driver had written down the temperature every hour, and the store at Chakan where the grapes had waited overnight was running as it should. What went wrong had happened earlier, in a vineyard near Dindori, between about eleven in the morning and six in the evening, when the boxes sat at the end of a row waiting for a tempo.

I had built a company around the wrong end of the journey.

What the field leaves in the fruit

A grape or a tomato does not stop living when it is cut. It keeps breathing, using up its own sugars and water, and it breathes faster when it is warm. Fruit picked at noon carries the heat of the field with it; growers and engineers call this field heat. Until that heat is taken out, the fruit is ageing quickly, and no amount of cold later in the journey gives those hours back.

None of this is new. Every book on post-harvest handling says it, and I had read most of them. I had even taught it, in a borrowed classroom in Pune, to a batch of second-year food technology students. But knowing a thing and arranging your money around it are different. For our first six years, almost every rupee we raised went into the part of the chain a customer could see: the cold store, the trucks, the logger on the truck door.

Why we built it backwards

There were reasons, and they were not foolish. A cold store is something a bank understands. It has walls, a capacity in pallets and a rate card. A buyer can visit it. A shade net at the edge of a vineyard, a stack of plastic crates or a small shed with a pre-cooler is harder to explain on a loan application, and harder still to charge for.

We also listened to our customers, which is usually good advice. The buyers asked for cold trucks, so we bought cold trucks. Nobody asked us what time the grapes had been picked, because nobody at the receiving end could see it.

The result was a chain that was very cold in the middle and warm at the start. Our logbooks from those years show the same pattern season after season: the fruit spent longer between the vine and our first cold room than it spent inside our trucks.

What we changed

In 2019 we put a pre-cooler at each of our pack-houses, so that fruit lost its field heat within an hour of arriving instead of waiting for space in the cold store. A pre-cooler pulls cold air through the stacked crates at speed; Nitin explains how on page 9. At the same time we moved our collection points closer to the farms, so that the first journey was ten minutes on a farm road, not two hours on the highway.

Then we began asking growers to pick earlier in the day. It is the cheapest change of all, and the hardest to make.

The pre-coolers were the easy part. They are machines; you buy them, install them and train someone to run them. The collection points meant renting sheds in villages, which meant a sarpanch, a landlord and a power connection for each one. Picking earlier meant changing the habits of people who have farmed for longer than I have been alive.

None of it showed up in our rate card, and for two seasons it cost us money. Then the rejections began to fall.

What it cost, and who paid

I want to be plain about the money, because growers ask and bankers ask more. The pre-coolers, the rented sheds and the crates cost us about as much as one more chamber at Chakan would have. For two seasons that money earned nothing we could show on an invoice. Our rates did not change, because I did not yet know whether any of it would work, and it did not seem fair to charge growers for my experiment.

The growers paid in a different way. Picking at six means a team that arrives at half past five, and that team wants to be paid for the early start. Some growers found that easy; most did not. A few left us for a cold store with a lower rate and no questions about picking times, and two of them came back the following season.

The buyers paid nothing extra at first. They simply sent back fewer boxes, a saving they noticed and we did not, at least not on paper. It took a full season of logs to show them where the saving came from, and another season to agree a rate that shares it.

What the numbers say

Our logbook figures are on page 6, and I have tried not to dress them up. The short version is this. When grapes reached one of our pre-coolers within three hours of being cut, buyers turned away fewer than two boxes in a hundred. When they took more than twelve hours, it was closer to one box in seven. The truck and the cold store were the same in both cases. Only the first hours were different.

Six hours is not a magic line. It is where our own figures begin to climb steeply, and it is a target a grower can hold in his head: pick by ten, in the shed by eleven, in the pre-cooler by one.

What I still do not know

I do not know how far this goes for the crops we handle less often. Our numbers for grapes and pomegranates are good because we move so many of them. For greens, which wilt within hours, I suspect the line is much shorter than six hours; for onions, which we do not cool at all, it may not exist. I would rather say that plainly than stretch a grape number to cover everything.

Nor do I know how to do this for a grower with two acres and no tractor, whose crop leaves the farm on a shared tempo at whatever hour the tempo comes. Many of the growers who supply us farm like that. The collection sheds help them more than anyone, but a shed still has to be within reach, and we cannot rent one in every village. If you have solved this somewhere, I would like to hear how.

What I would tell a new cold-chain company

Spend your first rupee at the farm gate, not at the city end. Measure the time from the knife to the first cold room on every load, and print it on the delivery note so the buyer sees it too. Pay your collection staff for early arrivals, not for full trucks.

And go and stand in a vineyard at noon, with your hand on a box of grapes that has been waiting two hours for a tempo. You will understand the business better than any spreadsheet can tell you.

I still believe in cold stores. We run one at Chakan and it is full for most of the year. But a cold store can only keep what the first six hours have left it. •