How a Yoshan Coffee Roaster Is Built: 30 Steps from Cast Iron to Your Door

You are about to wire a five-figure deposit to a factory in Shenzhen you have never visited, for a gas appliance that will run in your building every day. “We are a real manufacturer” is not enough to go on. So instead of telling you that, this page shows you the work — every step a roaster goes through in our plant, and what you are allowed to ask for as proof at each one.

Why we lay the whole process out

Most roaster websites, ours included until now, have one “factory tour” article and a lot of product pages. That leaves the questions that actually stop a purchase unanswered: Is the drum really cast? Who wires the panel for my voltage? Does anyone roast coffee in the machine before it is crated? What is in the crate?

We have built drum roasters since 1990 — from 100 g sample machines up to 300 kg industrial lines — and today they are made in our own factory in Guangming District, Shenzhen: 4,624 m² of floor, three production lines, verified on site by SGS. Every machine goes through at least three inspections before it leaves.

Our own production sheet lists the work in eight stages: blanking, welding, polishing, spraying, assembling, power distribution, quality inspection and debugging. The thirty steps below are those eight stages broken down to the level a buyer can ask questions about. The pages linked below break that work into individual steps so you can check each one.

The build sequence

The order below is the order a machine moves through the plant. Each step links to its own page.

1. Materials and drum

• What a roaster is made of — cast iron drums on SD and YS series, 304 stainless drums on DY and EC series, 304 stainless panels, and how to tell 304 from cheaper grades.
• Why we cast our drums in iron — heat retention, turnaround after charge, and what that does to batch-to-batch consistency.
• Incoming material inspection · Drum machining · Drum balancing

2. Sheet metal and structure

• Laser cutting · CNC bending
• Welding — the step that decides whether a gas roaster is safe ten years from now.
• Grinding and deburring · Brushed and polished finishes

3. Surface and branding

• Electroplated 304 shell — corrosion protection for coastal and humid roasteries.
• Powder coating and custom colours — red, black, white, blue, green, yellow, copper, silver, or your own colour.
• Your logo on the machine — silk screen, laser etch and nameplate.

4. Assembly

• Burner train assembly — nozzles and regulation set for LPG or natural gas before shipping.
• Control panel and wiring — German temperature probes, Siemens touch screen on YS and SD Pro, wired for your voltage.
• Key components we do not make ourselves — Weishaupt, Siemens, ADDKA, OMRON, and why we name them.
• Drive system · Final assembly

5. Testing — every machine, at least three times

• Three-stage factory inspection — what each of the three checks covers.
• Gas leak and pressure test · Electrical safety test · Heat-up and dry run
• Test roast with real green coffee — the machine you receive has already roasted coffee.
• Final QC and remote video inspection — you watch your machine run before the balance is due.

6. Packing and shipping

• Export packing — film, fumigated wooden case, ISPM-15.
• Container loading · Shipping documents · Sea freight timeline

7. After arrival

• What is in the crate — the tool kit, spare fuses, gas nozzle, pressure gauge and exhaust pipe that ship with every roaster.
• Installation and exhaust · Operator training
• Warranty and spare parts — one-year whole-machine warranty and how parts reach you.

Five points where you should ask for evidence

You do not need to visit to verify us. At these five points, any buyer can ask — and we expect you to:

1. Before deposit: the drum material and wall thickness of the model you are buying, in writing.
2. During production: photos of the welded frame and drum before paint.
3. Before balance: the roast curve from the factory test roast, and a live or recorded video of your machine running.
4. Before shipping: photos of the crate with the ISPM-15 mark and the packing list against the crate contents.
5. After arrival: the accessory list checked against what is in the box within 24 hours.

If a factory — any factory — will not give you these, that tells you more than any brochure.

What we buy in, and what we build

We are open about the parts we do not manufacture. Automatic control on the YS series and the SD Pro series runs on a Siemens system with a Siemens touch screen. Burners on the largest machines — SD-30 Pro and above, YS-120 and above — are Weishaupt. Temperature probes are German-made, with dual bean and air probes on the YS series. Drum, cooling and fan drives on the YS series use four independent ADDKA motors, and industrial lines use OMRON pneumatic servo control. Everything structural — drum, body, cyclone, cooling tray, frame — is cut, welded, finished and assembled in our own plant. The key components page explains why this mix, and why it matters for spare parts in your country.

Frequently asked questions

Do you publish prices?

Yes. Every product page shows the current price in US dollars, EXW Shenzhen, from our 2026 price list — for example the DY-1 at USD 2,599 and the YS-6 at USD 7,499 — together with extended-warranty and bundle options. The quotation adds freight to your port and any custom colour or voltage items.

Can I visit the factory?

Yes. We are in Guangming District, Shenzhen, about an hour from Shenzhen Bao’an airport and reachable by high-speed rail from Hong Kong West Kowloon. Tell us your dates and which models you want to see running; we schedule a test roast so you can cup the result, not just look at the machine.

If I cannot visit, how do I check the machine before paying the balance?

Every machine is filmed running before it is crated, and we can do a live video call at your chosen time. You choose what to look at — drum rotation, flame, cooling tray, control screen, a full roast cycle. See the video inspection page.

How long does production take?

It depends on the model, colour and voltage. Standard-colour machines in the 1–6 kg range are usually quicker than industrial lines or custom colours. When you send us your country, voltage, gas type and weekly volume, the reply includes a production time for that exact configuration.

Can I buy only part of the line, such as a destoner or afterburner, to add to a roaster I already own?

Yes. We build destoners, ESP smoke filters, afterburners, loaders, sealing and filling machines as separate items, and we have made custom loaders for machines from other manufacturers. See roastery equipment.

Which certifications do you hold?

Our roasters are CE certified under the Machinery Directive (certificate AH2023062101, with the Low Voltage Directive covered on the 2020 certificate for YS-20 to YS-200), RoHS certified (AH2023062102), and food-contact tested to FDA 21 CFR (SCT report RC2605141067, June 2026). Our factory has been audited on site by SGS. Every certificate is shown on the certifications page. Tell us your country at quotation and we confirm which burner documentation your inspector will accept.

Final thoughts

A roaster is a welded steel body around a cast drum, a burner, a control panel and a lot of testing. None of that is secret. We have put it all on these pages so you can judge the work rather than the sales pitch, and then choose a machine from the SD series, the YS series or the full commercial range knowing what is inside it.

Last updated: September 22, 2026