Guides

How to log roast batches and track weight loss

A roast log is the link between green coffee and the bags you sell. Profiling tools record what happened inside the roaster. A batch log records what went in, what came out and which order it was for, so stock, yield and orders agree.

What to record for every batch

Keep the log simple enough that it is filled in every time, not only on quiet days.

• The green coffee used, down to the sack or lot.
• Green weight into the roaster.
• Roasted weight out.
• Roast level or profile name, the date and the roaster.

Calculate weight loss

Weight loss is the share of green weight that does not come out as roasted coffee: (green weight − roasted weight) ÷ green weight × 100.

Track it per coffee and roast level. A batch that sits well outside its usual range is worth a look: a weighing mistake, a different profile, or a coffee that has changed in storage.

Work backwards from orders

Once you know a coffee's usual weight loss, you can work out the green coffee an order needs: roasted weight needed ÷ (1 − weight loss as a decimal). That turns a list of orders into a list of what to roast and which sacks to pull.

Blends need a recipe that reaches the packing table

Whether you roast components separately or together, write the blend down as percentages, then convert it into grams per bag for the pack sizes you sell. The person packing should not have to do the arithmetic.

Profiling and batch logging are different jobs

Roast-profiling software records temperature curves and helps you repeat a roast. A batch log ties that roast to stock and orders. Many roasteries need both, and they work best when each does its own job.

Updated 21 October 2026