My First Green Bean Purchase Experience! Details to Pay Attention to When Buying Coffee Beans

Pay Attention to Defect Rate When Buying Coffee Beans!

Defect rate! Defect rate! Defect rate!

Mandheling G1 Analysis

1. Mandheling G1: 500g of green beans, 140 defective beans, a defect rate of 29%. This batch had such a high defect rate. It looks decent on the surface, but on careful sorting...

...there were in fact so many defective beans, and the more I picked, the more I found. Defective beans that don't affect health have not even been picked out yet. The bean sizes also vary greatly, with both flat and round beans, making them difficult to sort.

I picked until I was full of frustration. How terrifying. Is this the green bean supplier's problem, or are all Mandheling G1 beans like this, with such high defect rates?

Guatemala Huehuetenango Analysis

2. Guatemala Huehuetenango: 500g, 48g of defective beans, a defect rate of 9.44%. That defect rate is acceptable, but these beans are the yellowest of the four varieties.

And they are not natural-processed beans. They are probably past-season beans. Fortunately the flavour has not yet developed musty notes.

Kenya AA Analysis

3. Kenya AA: 500g, 40g of defective beans, an 8% defect rate. Large beans are easy to sort and carry low defect rates. Highly recommended.

Ethiopia Sidamo Analysis

4. Ethiopia Sidamo: 500g, 15g of defective beans, a 3% defect rate. Small beans but a low defect rate. Recommended.

Online Purchase Risks

Buying beans online always comes with risks. Please use this as reference.

Important Health Note

The picture above shows defective beans. Black beans, insect-damaged beans and mouldy beans must be removed; consuming them will certainly affect your health.

FrontStreet Coffee is a roastery in Guangzhou with a small shop but a wide range of bean varieties. You can find many famous and lesser-known lots, and it also provides online store services.

FrontStreet Coffee Recommendation

This is exactly why grading and sorting matter. Golden Mandheling, which PWN produces, is screened to an unusually strict standard: beans of 18 mesh and above, and fewer than three defective beans in a 300-gram green sample for the top G1 grade, followed by one machine pass and three rounds of hand sorting that remove the defects almost completely. The payoff is a clean cup with a notably strong sweetness, and beans that are large, even and bright. Most of PWN's output goes to Japan and the United States, so genuine Golden Mandheling is scarce elsewhere; FrontStreet's lots come with PWN certificates and marked bags precisely so buyers can tell them apart from imitations.

For the classic earthy side of the style, FrontStreet's Lintong Mandheling comes from the traditional Mandheling region around Lake Toba in North Sumatra. Wet-hulling and a medium-dark roast leave it low in acidity and full in body, with clove and woody aromatics, a spice-and-mint edge and a strong, lasting sweetness — a natural choice for anyone who dislikes sour coffee. Its pour-over is best expressed at 87–88°C with 15g of coffee at 1:15 and a coarse-sugar grind, poured in three stages: a 30ml bloom, then 100ml, then a gentle 95ml centred pour, which together deliver the thick body, caramel sweetness and chocolate and nut notes. Brewed on an espresso machine, FrontStreet's classic blend sets medium-dark Mandheling over Brazilian creamy-nut coffee for butter, roasted chestnut and caramel, adding sandalwood, herbal and spice notes, with a little Robusta for a fuller crema and easier latte art.