What grain drying actually costs

Grain drying has two costs, and most back-of-the-diary sums only count one of them. The first is the running cost — fuel, electricity, labour — typically £2–£3.50 per tonne for each percentage point of moisture removed. The second is the weight: the water that leaves the heap was tonnage you'd have been paid for, and on a decent moisture reduction it's a bigger number than the fuel bill. Add the two together and drying a wet crop costs meaningfully more than the drier's fuel gauge suggests — which is exactly the sum you need before deciding whether to dry at home, pay commercial charges, or sell wet and take the merchant's moisture claim.

Cost one: running the drier

The convenient unit is pounds per tonne per percentage point removed, because it scales with how wet the grain actually is. As a rough UK guide, £2–£3.50/t per point covers most on-farm setups, with the spread mostly down to fuel type and price, drier efficiency, and whether labour gets counted honestly.

So taking wheat from 18% to 14.5% — three and a half points — costs somewhere around £7–£12 per tonne in running costs. Taking a properly wet 20% crop to the same spec is five and a half points, £11–£19/t. Wet years don't just mean more loads through the drier; they mean more cost per load.

Commercial and co-op drying charges commonly land at £15–£25/t depending on the moisture band, which usually looks expensive against home drying's marginal cost — until you price the capital, or you're the farm with no drier in a season that needed one.

Cost two: the weight that leaves with the water

This is the forgotten half. Grain is sold by weight, moisture included, and drying removes moisture — so the dried heap weighs less than what came off the field. The arithmetic:

dried weight = wet weight × (100 − wet %) ÷ (100 − dry %)

Take 100 tonnes of wheat at 18% dried to 14.5%: 100 × 82 ÷ 85.5 = about 95.9 tonnes. Roughly 4.1% of the weight — four tonnes on that hundred — went up the drier stack as water vapour. At £180/t feed wheat, that's about £740 of tonnage gone before the fuel is counted. It's not a loss you can avoid (nobody pays full price for water), but it is a cost you must include. Our guide to grain shrinkage covers this arithmetic in more depth.

The worked example: dry it or sell it wet?

The genuinely useful comparison is home drying versus the merchant's moisture claim for taking grain over spec. Say you have 100 tonnes of feed wheat at 18%, contract max 15%, price £180/t:

	Dry to 14.5%	Sell wet at 18%
Tonnage sold	~95.9 t	100 t
Drying cost at ~£2.75/t/point × 3.5 points	~£960	—
Merchant claim (weight and drying deduction, varies)	—	commonly £8–£15+/t, say ~£1,100
Weight loss value at £180/t	~£740	claimed within deduction
Rough net position	~£16,300	~£16,900 minus claim risk

The numbers are illustrative — claims vary widely by buyer, season and contract, so check yours — but the shape of the decision is real: at modest moisture excess the two routes often land closer together than people expect, and the choice turns on the details. Which is why the honest answer is to run your own figures rather than a rule of thumb: our grain drying calculator does the weight-loss and cost sum per load in a few seconds.

Two things tip it in practice. Merchants' claims are priced to cover their risk and their drying margin, so they're rarely generous. And grain over spec has fewer homes — you're negotiating from the back foot, in a queue.

Wet years change the maths

In a catchy harvest everything moves against the seller of wet grain at once. Intake moisture claims rise because the merchants' driers are the bottleneck. Haulage queues lengthen. Buyers get choosier about marginal loads because they have plenty of wet grain already. Meanwhile the farm drier, whatever it costs to run, keeps working at the same £/point it always did.

That asymmetry is most of the case for on-farm drying capacity: it's insurance priced in fuel. The choice of drying system is a separate question, but the wet-year economics are what justify owning one at all.

Dry the wet loads, not the whole heap

Loads off the same field on the same day can span two full points of moisture — morning grain cut in dew against mid-afternoon grain. If every load's moisture is recorded at intake, the wet morning loads go through the drier and the dry afternoon loads go straight on the floor. If nothing is recorded, the cautious answer is to dry everything, and you pay £2–£3.50/t/point on tonnes that never needed it.

On any real tonnage that discipline pays for itself quickly — a meter reading per load takes seconds, and a meter you've checked against the merchant's intake figures makes the readings worth acting on. Recording moisture against each load at the weighbridge also builds the per-shed picture that decides what needs moving first in spring, and the moisture context is what makes sense of safe storage levels later.

Frequently Asked Questions

How much does it cost to dry grain per tonne in the UK?

On-farm drying typically runs £2–£3.50 per tonne per percentage point of moisture removed, so taking wheat from 18% to 14.5% costs roughly £7–£12/t in fuel and running costs. Commercial or co-op drying charges are commonly £15–£25/t. On top of either sits the weight loss — the water removed was saleable tonnage.

How much weight does grain lose when dried?

Dried weight equals wet weight × (100 − wet %) ÷ (100 − dry %). Drying from 18% to 14.5% loses about 4.1% of the weight — around 4 tonnes on a 100-tonne heap. The wetter the grain arrives, the bigger both the fuel bill and the weight loss.

Is it cheaper to dry grain or sell it wet?

It depends on the merchant's moisture claim, your drying cost, and the season. At modest excess moisture the routes often land surprisingly close; in wet years claims rise and wet grain has fewer homes, which favours drying at home. Run the actual figures per load rather than relying on a rule of thumb — the arithmetic takes minutes and the difference can be four figures on a shed.

Why record moisture for every load?

Because loads vary — morning loads cut in dew can be two points wetter than afternoon loads from the same field. Per-load readings let you dry only the wet loads instead of the whole heap, which at £2–£3.50/t/point is a real saving, and they give you the record that explains tonnage differences at sale time.