Every cold-press juicer produces two things: the juice that fills the cup, and the solid fibrous mass that gets pushed out the back of the machine. At most juice bars, the second thing ends up in a bin. We wanted to know exactly what happens to ours — not in a vague "we compost responsibly" way, but in a day-by-day, kilogram-by-kilogram way. So for the week of Monday 9 September through Sunday 15 September, one of our staff members weighed every batch of pulp before it left the press room, logged the crop source and moisture level by feel, and recorded where it went. What followed surprised us in a few places and confirmed a few hunches in others. This is that log, more or less unedited.

The method: a kitchen scale and a shared spreadsheet

The setup was not complicated. We placed a tared 10-litre bucket on a Tanita KD-321 commercial kitchen scale next to the press rack. After each pressing cycle — we run the Goodnature X-1 Mini in two-litre batches — the operator scooped the pulp cake into the bucket and called out the weight to whoever was logging. We used a shared Google Sheet with five columns: date, time of pressing, crop blend, wet weight in grams, and an estimated dry-matter percentage based on a squeeze test we calibrated loosely against a Yamamoto Farm reference sheet from their 2023 soil-amendment trial. We did not have a lab moisture analyser on site, so the dry-matter figures carry an error margin we are putting at roughly plus or minus 8 percent. Bear that in mind when reading the totals.

Monday through Wednesday: the heavy carrot days

The first three days of the log were carrot-heavy. Clay Crest Zone runs a rotating seasonal base, and the week of the 9th fell squarely in the middle of our autumn Fushimi Ninjin blend — a purple heritage variety sourced from Yamamoto Farm's eastern plot, supplemented with conventional Kintoki from a Kyoto wholesale market. Carrot pulp is the densest we produce: low moisture, almost crumbly out of the press. Monday logged 4.2 kg wet weight across eleven press cycles, Tuesday 3.9 kg, Wednesday 5.1 kg (we had a private catering order that pushed volume up). By Wednesday evening the refrigerated holding bin held 13.2 kg total. Yamamoto Farm collects every Thursday morning, so that three-day accumulation becomes one figure in Kenji Yamamoto's intake log: he recorded it as 12.8 kg on arrival, a 400-gram discrepancy we attribute partly to drainage overnight and partly to the scale differences between his platform unit and ours.

Thursday: the handoff and what Yamamoto Farm does next

Kenji Yamamoto or his son Riku pulls up in a white Daihatsu Hijet around 7:40 most Thursday mornings, which is before we open the front counter. The exchange takes about four minutes. He brings back empty buckets from the previous week and takes the full ones. The pulp goes into a covered windrow on the north side of the Yamamoto plot in Fushimi-ku, mixed with rice straw and a measured dose of bokashi inoculant — a ratio Kenji described to us as roughly three parts pulp to one part straw by volume. He told us the carrot pulp in particular breaks down within 18 to 22 days at current September temperatures, and the resulting compost goes back onto the beds where the Fushimi Ninjin is grown the following spring. It is a short, closed loop: about 800 metres between our press room and the field.

Thursday through Saturday: the mixed-citrus complication

Thursday afternoon we shifted into a citrus-forward run for a weekend menu addition — yuzu, Amanatsu orange, and Hyuga-natsu, all sourced from a Miyazaki prefecture broker via the Tambabashi wholesale terminal. Citrus pulp behaves very differently from carrot. It holds more moisture — our squeeze test suggested 78 to 82 percent water content versus carrot's 55 to 60 percent — and the essential-oil residue in the peel can slow microbial activity in compost if concentrations get too high. Kenji flags anything above roughly 30 percent citrus in a weekly batch as requiring a longer cure time. Our Thursday-to-Saturday citrus pulp weighed in at 6.7 kg wet, a figure Kenji accepted but noted would sit in a separate holding pile for an extra two weeks before joining the main windrow. The total week weight across all crops came to 19.9 kg wet, or approximately 8.1 kg estimated dry matter.

The full week log, in one place

Here are the seven daily figures, which we are also publishing as a downloadable CSV linked from our sustainability page. Monday 9 Sep: 4.2 kg wet, carrot-dominant. Tuesday 10 Sep: 3.9 kg wet, carrot-dominant. Wednesday 11 Sep: 5.1 kg wet, carrot with 15 percent apple. Thursday 12 Sep: 2.3 kg wet, transition day, mixed carrot and citrus. Friday 13 Sep: 2.1 kg wet, citrus-dominant. Saturday 14 Sep: 2.2 kg wet, citrus-dominant. Sunday 15 Sep: 0.1 kg wet, single mid-afternoon press run, apple-ginger, retained for staff meal prep. Total: 19.9 kg wet. For context, our press room has been operating for 14 months. We have been tracking pulp weight for six of those months. The September week sits near the high end of our weekly range, which runs from about 11 kg in slow weeks to 22 kg in event-catering weeks.

What the numbers suggest about press efficiency

Pulp weight is, among other things, a proxy for press yield. A heavier pulp cake from a given quantity of produce means you are leaving more juice in the fibre, which either reflects produce characteristics — fibrous heritage varieties yield less than commercial ones — or press pressure and cycle time. Our Goodnature X-1 Mini runs at a fixed hydraulic pressure, so variation mostly tracks produce type. The carrot-heavy days in this log averaged 2.67 kg of produce per litre of juice sold, against a manufacturer reference of roughly 2.4 kg per litre for standard carrots. That 11 percent gap is consistent with the Fushimi Ninjin variety, which Kenji Yamamoto has previously described as running drier than commercial Kintoki because of the lower irrigation regime on his eastern plot. The citrus days ran closer to the manufacturer figure: 2.1 kg produce per litre. We are not drawing firm conclusions from a single week, but the carrot gap is worth watching.

What we plan to do differently

Three things came out of this exercise. First, we are going to add a pH strip test to the citrus pulp before handing it off, so Kenji has one more data point for setting cure time rather than eyeballing oil content. Second, we want to extend the log to a full quarter — September through November — to see how pulp volume changes as the winter citrus season deepens and the carrot harvest winds down. Third, the Sunday figure is interesting: 100 grams from a single press run is almost nothing, and right now it goes into a staff salad. We are thinking about whether a small-batch cracker or dehydrated dog-treat product built around low-volume daily pulp is worth testing. Yamamoto Farm has expressed no opinion on this plan, which we are taking as a neutral signal.

The full September week CSV is available on our sustainability page. If you work in food service and are tracking your own waste streams, we would be genuinely curious to compare methodologies — the contact form is real and someone reads it. Next log covers the week of 14 October, when yuzu volume historically doubles and the carrot supply from Yamamoto's eastern plot transitions to a neighbouring grower.