How to increase solubility


#1

I roasted some Peru Finca el Palmo beans from Bella Barista for espresso using the two Ikawa espresso roast profiles. No 2 led to a result that is too roasty in the cup. No 1 tastes fine, but it has a rather low extraction yield (18.4%). I wonder what I might change in the profile to increase solubility.


#2

Can you post the profiles you used?
To share profiles I first copy the link and screen shot the profile, then I go to my “photos” app and send the screen shot in an email and paste the profile link in the from the email (sent to myself) I download the image to my computer and copy the link. Next I log into the forum then compose a reply, the 7th option tap is the upload button, I upload from my computer because I don’t know why the other one doesnt work and lastly paste the link.


#3

Have you tried boosting the extraction od espresso? Longer shot, a bit higher temoerature etc? Also what is your ratio used for the shot?

Otherwise I would say adding development to the better profile in little steps. But first I would try to push the extraction to the limit, and see what I can get from it.


#4

I’d suggest you’ll have a look at this article. The core question though: why do you want to reach a higher solubility? A ‘good’ extraction yield is deemed to be in the area of 18-22% which you clearly are. And higher yield certainly does not mean better taste.
So personally I would more aim at a better coffee then at a higher extraction yield.


#5

Thank you for your reply and the link to your article, which I found very informative. It has been my experience that, within reason, higher EY does produce more enjoyable espresso – brighter, better-separated flavours and more intensity. With lighter roasts and 1:2 ratios, I commonly get around 20% EY, more if I use higher ratios. Darker roasts, in general, seem to extract a bit more. (If it’s helpful, I grind with a Kafatek Monolith Flat and brew on a Londinium 1, lever machine.)


#6

I used a brew ratio of 1:2. I’ve tried your suggestions, and that does indeed boost extraction by a percentage point or so. When you speak of adding to the development in little steps, you could mean longer time post-FC, or in another stage. Higher or lower temperatures. Changes in rate-of-rise. I hardly know where to start.


#7

You can find the two roast profiles (links and screen shots) that I used at the bottom of this blog from Geoff/Ikawa: https://www.ikawacoffee.com/exploring-roasts/


#8

I don’t see any profiles or screenshots at the bottom of the blog post.


#9

Well my method is to extend the profile, and I would make a few samples in 15s intervals. I think its not the best method but its very simple to do and predictable (when compared to changing the profile points) … and you will see if you keep your extraction method the same, how it will change what you get out.
Sure for best taste it would be better to change the profile instead of extending it, but I think this at least helps you find the best point on that profile to end the roast.


#10

I most often do 30s steps, but its for other purpose, 15s I think would be better for this fine tuning.


#11

I’m so sorry. I gave you the wrong link. This should work:

https://www.ikawacoffee.com/roasting-for-espresso/


#12

My advice is to first measure the before and after roast, weight of the coffee. You want to be in the 13-15% for third wave 15-17% for second wave and 18% for grandpa joe coffee. These percentages are the moisture loss measured by weight, you may be thinking that obviously more is lost than just moisture and yes you are correct for for a complicated question I give you a simple answer.

Moisture loss is linked to cell wall breakdown which is linked to solubility. Momentum in the roast will effect cell wall breakdow (moisture loss) more than slight +/- degree changes. But a very high temp 470-480*F and up also can drastically increase solubility but at the same time this temp area leads to lots of flavor complexity loss and burning off sugar flavors and baking out all flavors. However if done right can lead to very specific flavors and a satisfying cup.

To reiterate (but with more knowledge, and not going to defend it) I think spikes are not good, especially since the beans have higher thermal mass then everything else. If the roaster was made (in the roast chamber area with a less conductive metal) then a spike or a charge would be useful. Having the green bean trying to store thermal energy is going to lead to a premature breakdown and flavors and burn off the outside molecules.

Something interesting with coffee is terrior plays an important role in flavor similarities, varietals play similarly (I’m not 100% on this). A Peruvian bean may roast better using a profile made for a bean in a closer region, maybe try using a Guat profile.

Understanding the bean you are using is fundamental to building a working knowledge.


#13

There is a ton of fascinating, and potentially useful, information in that reply. Thank you very much.