New Crop Green Coffee

Is it possible for a green coffee to be too fresh? I live in Thailand and bought a 50kg bag of a washed coffee from a northern province and it seems even when I roast it to a medium degree and it has an undrinkable amount of vegetal taste notes, over the past 2 months the dry aroma of the bean seems to be getting more bell pepper like and less on the extreme vegetal. I believe it to be chlorogenic acid, I have roasted many other coffees without nearly the same amount of bad result as this bean. Anyone have any inside information on fresh crops? (as this crop is from Dec 2023) Any tips tricks or help would be great appreciated. :grin:

Maybe post your roast profile and the bean process and altitude along with this, so people can get a sense of things.

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Thailand Mae La Noi Washed
Village:Baan Huay Kung (บ้านห้วยกุ้ง)
District: Mae Ho (แม่เหาะ)
Province: Mae Hong Son (แม่ฮ่องสอน)
Altitude:1,100-1,250 masl
Plant Varietal:Catimor, Bourbon

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No, the coffee can’t be too fresh. Once the correct moisture content is reached and it is packaged for sale, there’s really not much difference between 3 or 6 months. Anyway, I’d go for a longer roast, FC closer to 9 minutes, and see how that goes. After that I’d adjust accordingly. At times, if you’re looking for a perfect roast, it will take you more than 2-3 tries. Also, it’s important to know what notes you should pull out of it. In this case, the farmer, or whoever you bought from, is your friend.

I don’t think there’s any way to confirm this but could it be possible the cherries were picked too early before they were fully ripe?

I think I found your profile for the image above. I noticed you reach yellow very quickly - after just about 3 mins. This to me is very fast. You may want to try to stretch out that drying phase to at least 5 mins since the beans may still have high moisture content. Your PH temp is also high, IMHO, for a 600g batch. I tend to use lower PH for a batch that size, 419F (215C) and my yellow is marked anywhere between 5 and 5:30. Just my 2 cents that you can try out since you have 50kg of that bean to play with.

I have to say Thailand is finally producing really good beans but so hard to get in the US :slight_smile:


I went with a wider “prolong the roast” thing, because he said that the other roasts were just fine, but they too are going yellow at around 3 minutes. There are those marked at incorrect temperatures, but those too are around 3 minutes when you look at the correct temperature. There are 2 or three that are correctly marked at around 4m, 4m and something, but that’s just 2 or 3. I have looked at all 78. There is another possibility, which is a dirty sensor that tells higher temperatures, but he dumps the coffee at lower than desired, hence grassy flavours. Who knows? We’ll see once he gets back to us.

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Could be a moisture issue, I dont have a moisture measuring device but I will try to get one at the end of the month for quality control. Since I’ve gotten the green bean, the aroma of the green bean has changed from so overwhelmingly grass to bell pepper to getting to a more normal washed aroma. Strangely, the roasted bean now is absent of the chlorogenic acid after degassing for around 40 days, my concern wasnt for the roast being good, it was that the chlorogenic acid was so strong and of to such a high level that it was actually made me gag during cupping, as I had roasted a number of other washed thai coffees that were from last season to good results. now that I can actually taste the roast, it needs work but not gross and undrinkable which is a huge change in my view. A friend of mine who used to work for a roaster near me told me they would often age their coffees for up to a year for the correct moisture content I believe, this is the first crop of the season for that area so they could have harvested it a bit early too.

If you look at my other roasts, some of the profiles I was in production mode and missed marking yellow on occasion :sweat_smile:

Extending my time to yellow is something I do need to work on and I will try it for this, but for most of my roasts as is I do get good results I am happy with but I do have room for improvement. I am self taught and watch lots of youtube, podcasts and read some books, so I do make jumps in my roasting ability, maybe this will be another moment. There arent many classes in english where I live for a fair price so its hard for me to get formal education in this, my sensory skills are self taught along with one of my thai friends helping me who has had roaster training. I do attend as many public cuppings as possible :sweat_smile:

Moving forward I will play with a longer roast and extending the roast time a bit, I will roast a bit today and see how that fairs.

Yes Thailand coffee is incredible it is my favorite origin, in the last few years there has been such a boom in specialty coffee here, Ive lived over here for 6 years and didnt like coffee until 5 years ago when my eyes were opened. I feel lucky to enjoy all they have to offer, in a few years I hope to move back and bring Thai coffee for enjoyment to the usa :grin:


For the dumping, for my first 20 was alot of experimenting, if they would stall for a while I would dump as the color would be getting darker or the time since first crack was long, Ive changed since then in my thinking, I find more success in this larger batch size as well too. I will try that lower charge today :grin:

The photo of the beans in your first post shows most of the beans being a light color but darker in the lower right. Are the darker beans wet? If so, maybe spread the beans out on a tray a day or so before roasting to dry them out a bit. Or perhaps it’s just a shadow🙂. Michael

@beaunistler.Wh1m And Thailand being quite humid as well it didn’t surprise me that your friend said they “age” the beans as long as they do.

Don’t worry… many of us here are all self taught, myself included (I started on a FreshRoast SR500 air roaster and jumped to the Bullet). With your 50kg you can definitely use that to experiment on the profiles on the Bullet. Your condition of being in a more humid and warmer climate can affect how the profile works out.

I lived in Thailand for nearly 20 yrs, moved to the US in the late 1980s - I still have family there so I go back occasionally and it used to be that I would bring my own beans back with a portable hand held grinder so I can have good coffee in the morning at my parent’s place :smiley: Several many years ago (10+ yrs ago I think) I visit my childhood friend in ChiangMai and boy the amount of good coffee there from the locally grown beans was fabulous at the time, it’s took a bit more time for that to get down to Bangkok. Lots of mom-and-pop type shops which is wonderful - but ain’t cheap either by Thai cost-of-living standards.

I think you’ll find plenty of resources referred to in these forums. Rob Hoos’ e-book is referred to quite a bit, as well as CoffeeMind’s YT videos and free online course for Bullet owners (search the forums for the link).

Happy Roasting!


Well, my personal process is to always blame myself first before searching for other reasons. Then I would work towards correcting that. Here, you have a few options as to how to go about with prolonging your roast. Even if you maintain the same preheat, you can do a heat soak and/or go with lower power settings at the beginning. Who knows, maybe Uriel’s recipe is what you need. Of course, just as a guideline, as you’re roasting different beans in a different environment. You do mention that courses are expensive, but you can find a lot here. For example, the Morten Münchow course, which is free for bullet users.

Also, if you’re struggling with flavours, you can download a sensory lexicon from the World Coffee Research site. The SCA flavour wheel is based on that, and you can find much more stuff on their site. There’s also the interactive flavour wheel posted here.

You can find much on Münchow’s Coffee Mind site. And there is a lot of quality reading material at the Cafe Imports education section. That should cover the concepts, but don’t get lost in the science and number watching. I’ve never had good results when I concentrate on what I’m supposed to do instead of doing. Of course, you must have a reference. You must know how the coffee should taste like so you can perfect your roast.