I was thinking about this as I picked through my roast this afternoon. Do most people cull through their beans before roasting or after? I am assuming that those that cull before also do so afterwards as well.

The longer I have been home roasting, the more important this has become for me. I tried an experiment where I pulled a few shots and then threw a few defect beans into a couple shots and the difference was very noticeable. Now I really try to work through the beans, but I do it after roasting. I will pull the occasional broken bean or obvious defect from the greens if I spot them during weighing, but for the most part only cull through them after roasting. To me, it seems easier to inspect the beans after roasting, in part because the defects become more obvious, and in part because you have to inspect them afterwards in any event (quakers, shells, etc). I was hoping to hear from others to see if perhaps there are things I am missing by only culling after roasting.

Immature floater beans turn into quakers (very light colored) after roasting, and are much easier to catch at that point. It's customary to remove them, but they are not a big deal, since they taste like Post toasties.

One partial black or partial sour will ruin a shot; full sours or blacks will ruin an urn's worth of coffee. So, before roasting, remove any bean that is partially or wholly the wrong color - black, red or orange. The red or orange ones can be an odd silverskin. If they are, the color can be scratched off with your fingernail.

Coffeeresearch.org has a few pages on sorting green beans, they are worth a look (they picture the blacks as both "blacks" and "stinkers," and picture sours, as "greens")

Also, less commonly, don't forget that it is important to cull beforehand to eliminate rocks, stones, and foreign material.

That's is a good point, Adrian. What is the probability of encountering rocks with home roasting? I guess the answer depends on how much you roast and the source of green beans. But to be honest, I've never culled Oh I forgot. I used to cull lentils when I was little.

Cheers

I often cull before and after the roast; removing between 5-90 % depending on beans and intent.

I think it's cool that coffee doesn't come pre-brewed, at least to HBs, and we can do this kind of dissection.

Peter
How about sharing some culling thoughts. You should write "The Culling Book".

Thanks for all the replies. Some good information and I think I will add culling before roasting to my routine.

I often cull before roasting between 4-10g out of 400g batch size. This usually only takes me 5-10m. However I'm not always certain exactly the priority on which defects should be culled. Hopefully someone can shed light, but according to the previous link given (coffeeresearch.org) I would cull all of: black/stinkers, sticks/stones...most of: floaters, insect dmg, mold (they call this one green?), half black...the rest I place lower priority, but I'm not actually sure how much impact they have on flavor. My mind says not much, but as an experiment I've been saving the beans I cull, I'll then cull those into these groups and roast them up and taste! Hopefully the education will be worth the time.

After roasting I usually pick out the obvious underroasted beans and charred ones as I feel they would detract from a shot significantly if one was in. If I'm unsure and there's more than just a couple, I'll munch one to see what it's like and decide to keep that type or not.