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Weigh out: record the roasted weight and roast loss

Drop is not the end of the batch. The roasted weight turns a logged roast into roasted stock and gives you the number that tells you whether this batch matched the last: roast loss.

6 min read Updated October 19, 2026

Roast loss is the weight lost between green in and roasted out, as a percentage of the green weight. Factory calculates it for every batch from the actual weigh-in and the weight you enter at weigh-out, stores it with the roast, and averages it per profile. Because the weigh-in came from the scale rather than the plan, the figure reflects actual weights. Over a few weeks, it becomes your quickest consistency check: a batch two points off its usual loss was roasted differently, whatever the curve says.

Weigh out straight after drop

  1. Press Drop in the cockpit (or let auto-detect mark it). The feed freezes so the final curve stays on screen, the batch flips to Roasted on the Schedule, and the Weigh out the roast dialog opens with the batch number in its title.
  2. Read Green in: the actual weight recorded at weigh-in. Cool the beans and put the batch on the scale.
  3. Enter the scale reading in Roasted out. The line underneath updates live to the roast loss, for example 15.0% roast loss. If an identical earlier roast exists (same coffee, same profile, same green weight) Factory pre-fills the field from its loss as a starting point; it never guesses otherwise, so an empty field means weigh it.
  4. Optionally enter Agtron whole and Agtron ground from your color meter, and a note in Notes: anything you would want to read beside this curve next month.
  5. Press Save & finish. The roast is written to the device with its curve, events, weights and loss, queued to the cloud, the lot's green is finalized, the batch reads Complete on the Schedule, and the cockpit returns to the waiting screen ready for the next batch.
  6. Pressed Skip for now instead? The roast is still saved with its curve, but the batch stays Roasted until you record the yield, and it will not produce roasted stock in Roastnet until you do.
The Weigh out the roast dialog in Factory over the finished roast curve, showing Green in 12.02 kg, a Roasted out field with 10.22 kg, 15.0% roast loss, Agtron whole and ground fields, Notes, and Skip for now and Save & finish buttons
12.02 kg in, 10.22 kg out: 15.0% roast loss, saved with the curve.

Record the yield later

Skipping weigh-out is normal when the next charge is due and the beans are still in the cooling tray. Any batch in the Roasted state can be finished from the Schedule: open its row, and the dialog shows Weigh out the roast with Green in and a Roasted out field. Enter the weight and press Save & finish. The same section accepts Agtron readings. The roasted weight cannot exceed the green weight, and Factory flags this rather than saving an impossible gain. If you dismissed the weigh-out dialog in the cockpit by accident, press the completed Drop button again to reopen it.

Where the numbers go

  • Roasts: the archive shows In, Out, Loss and Duration for every batch, filterable by coffee, operator, machine and profile. Open a batch to see the loss beside its curve and the development ratio.
  • Coffee Profiles: each profile's Avg loss column averages the loss of the roasts that used it, and Target loss is the figure saved when the profile was created.
  • Roastnet: when connected, the completed roast converts green into roasted stock on the web, so wholesale orders, packing and the storefront draw from the correct roasted quantity.
  • Batch cards: a card printed after weigh-out (Print Batch Card on the row) shows the roasted weight and loss instead of the blank weigh-in box, ready for the roasted-beans bucket.

Reading roast loss

Light filter roasts of a washed coffee often lose 12% to 14%; espresso roasts sit around 15% to 17%; dark roasts and naturals go higher. Your own figures matter more than any table, so compare like with like: the same coffee on the same profile should fall within a point of its average. A batch that lost less probably dropped early or ran short; one that lost more went longer or darker. Moisture matters too, which is why a fresh lot of the same coffee can shift the figure. The roast loss guide covers how roast loss affects cost per kilo.

Weighed out

  • Roasted weight entered from the scale after cooling, not estimated
  • Agtron readings added when you have a meter
  • Skipped batches finished from the Schedule the same day
  • Loss compared with the profile's average before the next batch of that coffee

Where Roastnet helps

Questions roasters ask

Does Factory calculate roast loss automatically?
Yes. It divides the difference between the actual green weight and the roasted weight you enter by the green weight. It shows the result live in the dialog and stores it with the roast.
Why is the Roasted out field empty on one batch and pre-filled on another?
Factory pre-fills only from an identical earlier roast: same coffee, same profile, same green weight. With no match, it leaves the field blank so you weigh rather than accept a guess.
Can I correct a roasted weight after saving?
Not in Factory once the batch is Complete. If you skipped weigh-out at drop, the batch stays Roasted and you can enter the weight from the Schedule row. To correct a saved mistake, edit the batch in the Roastnet web app.
What are the Agtron fields for?
Roast color readings from a color meter, whole bean and ground. They are optional and are saved with the roast so you can check color targets against the profile later.

Run the roastery from one place

Green stock, roast plans, wholesale orders and the green coffee market in one platform, with a free roast-logging app for your machine.