S.O / Blend Roast Sampling Techniques?

[DesigningByCoffee]

Absolutely
350g has been my staple size for a few years, but I'm recently having good success with 700g too, with a fair adjustment in technique.
The biggest issue for me with post-roast blending has been not roasting enough to warrant it - but now I'm starting to 'supply' a few more opportunities are opening up…

[Steve82]

Update: that last El Sal batch was brilliant in milk. Too acidic for my tastes as an SO espresso, but I could possibly temper that with some roasting deeper into 2C. But certainly can see now how roasting different origins separately then blending would allow for real fine tuning & perfecting…

Since insulating my pan, I have tried 500, 450 , 400, 350g batches and have noticed a lot less or no difference in the end result. The 350g batch of greens is a great size, easier to control and repeat.

I have been doing several SO roasts at a time and experimenting with different blends, sometimes just at the grinder and loving that fine tuning aspect of it.
Really started to develop a preference for post blending, definitely results in more defined layers in 2 or 3 bean espresso blend for my tastes.

[DesigningByCoffee]

Update: that last El Sal batch was brilliant in milk. Too acidic for my tastes as an SO espresso, but I could possibly temper that with some roasting deeper into 2C. But certainly can see now how roasting different origins separately then blending would allow for real fine tuning & perfecting…

[DesigningByCoffee]

Well, can start to make some judgements. Todays doppio, from a slow roasted El Sal batch, has lost all the 'sourness' of previous roasts, while maintaining plenty of bright, sharp acidity that centrals are often known for.
Just and overview to wrap up. The idea was to take one SO bean, use a fast ramp to 1C, 'baseline' ramp to 1C and then slow ramp to 1C, all finishing with the same ramp to 2C and same drop point temp. Taste the difference. Point to note - my baseline profile is the one that seems to work best for my mocha/java blends (indo + eth).

Here are the three profiles to compare:

Fast ramp:


Baseline:


Slow ramp:


Conclusion
These El Sal (and probably other central) beans like a slower than usual ramp to 1C. This exercise just points out really that for each SO bean, a system of slow/baseline then faster roasts will allow you to clearly see the difference in different roast profile for various beans - if you can be bothered drinking the same SO beans for a month with varying degrees of success!

Anyway, I've found the process quite interesting. My question is - has anyone else discovered any general 'rules of thumb' for roasting various origins they'd like to share?

Cheers Matt


BTW - that last profile looks a bit odd when you compare to the others - I had to change my RM prefs to fit some longer roast time, so it is now displaying 25mins rather than 22mins… but it uses the same template…

[DesigningByCoffee]

Done another batch of the El Sal this week which I'll break into shortly - right on my profile line taken a little bit higher in temp but just on 2C.
Cupping notes TK :-)

Just an aside - the first batch has gone a bit sour - but could be brew temps with not enough machine warm up and a slightly faster pour - will try again tomorrow :-)

[DesigningByCoffee]

Here we go - case in point!
Just done a roast - 350g El Sal Aida. I would think that is quite a hard bean - so I've done a 'faster' ramp roast - all in the name of science! Next week I'll do the same bean - and go back to the 'normal' profile.
Let you know how I get on :-)

Matt

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Just an update. Into this bag over the last day or so, as a doppio through a naked PF & triple basket it is lovely. Fairly light body, not a heap of mouthfeel, but smooth and full of character. Hint of caramel & peanut butter. No sourness or bitterness (so right in the drop zone I reckon :-) As a FW - pretty mild.
Lovely bean! And good roast - but if I get a chance will do another batch with a different profile to compare…

[DesigningByCoffee]

The following screen shot is a good example of what I aim for now as a " basic standard " roast. Seems to produce a well balanced shot, which is what I am after. Then there is the factor of the machine I am generally using which is BES900 and that has so many parameters that can be adjusted to get the best out of the coffee anyway.
Loving this thread by the way, lots of great input from some experienced roasters.
Being able to control my process to the nth degree from green bean to cup has opened up a whole new world of variables to try, great fun trying all the different SO on BB.

Hi Steve
That's a great profile - well done!
It is certainly a process of fine-tuning and a good adj HG, DMM, cover and insulation really helps in getting the most out of each batch IMHO. The smaller batches help too - I normally do 350g - but as I'm going to do some more roasting I'l have to see whether I go to larger batches and what impact that makes. I have heard you can do 700g - but haven't tried it yet!

But keep playing - and posting your successes / failures - we can all learn from each other!

Cheers Matt

[DesigningByCoffee]

I still check in from time to time mate... Just keep a lower profile these days.

Fair enough - nothing new under the sun & all that! Always appreciate forward to your input though :-)

It's more about maintaining a specific profile rather than speeding up or slowing down the rate, as such. Over time I've discovered that softer beans need slightly less heat input in order to arrive at desired profile, as compared to harder, higher grown varieties which don't appear to be as sensitive. Your profiles look pretty good by the way, not too fast by Corretto standards. There's some very good info on this particular subject from the Willem Boot website here... Have always found the info here to be very enlightening.

This was a really interesting article! It certainly resonated with me, and gave me some good info as to why the Indo/Eth roasts I've been doing have worked so well, as his description for how to roast medium beans is kind of what I have randomly stumbled onto in my input/profile.

But the hard bean roasting description was interesting, and my exp with mexican/guat and recently ind ele hills (interestingly - is this a SHG bean?) seems to reflect this. The gentler profile I've been using leaves these beans underdone - so the question is whether I maintain my current basic profile but extend the roast into rolling 2C, just making them darker (which is what I've done in the past), or give them the berries early on (high temp right from the start rather than a gentle ramp), slow over rolling 1C then ramp again leading up to 2C like he suggests.

This second option would seem in theory to cook the beans better inside, while not giving any 'dark roast' drawbacks like burnt/bitterness flavours creeping in at the end into rolling 2C.

Will certainly be experimenting with this. I'm starting to roast for a few friends now - so will have more opportunity to experiment with post roast blending which will allow some more tweaking.

Thanks Mal

Cheers
Matt

[Steve82]

I have only been on the corretto for a year or so now. I cant really answer your more specific questions.

I have thought more recently about going down the temperature measurement route with the products available in BB.

However after much trial and error I have got a standard method down pat, using my senses, time and partial / removable covering, aka small plain steel pizza tray.

My heat gun stays at a set height. It only has high and low setting, I only ever use the low setting, unless on the odd occasion I feel I need to get a bit more heat into the roast briefly.

I keep the amount of greens the same at 500g.

So with a new bean I will hit it with my standard method and watch closely how it behaves. If it was a bit finicky, I will take some notes so I can remember for next time. I then add to that what the end result tastes like and from there I know where I can make slight adjustments in my roasting process the tweak it.

I generally do 2 or 3 roasts of a SO before I think about blending it. If I really like it as SO I usually don't blend it, just play with its roasting profile and how early I pull it before SC. I like to try and finish a bit earlier before SC to see the difference. However this usually ends up better for Aeropress or Cold brew.

I am pretty happy with where I am at and I find it easy to get repeatable results or make small tweaks as needed, which are time and temp adjustment is made by how much / how long covered for.

Like you, every bean seems to turn out pretty dam good on my standard go to method, even if I know that something could have gone a bit better. Adjustments can always be made in the brewing process as well. If I am happy with how the roast goes the first time, next time I happily go sit down and read the paper on the ramp to FC.

My standard method is.

30 secs preheat - extend this to 60 - 90 in colder weather.

Beans go in with no cover for 4 mins. - if I want a longer ramp time to FC I will lengthen this.

Cover goes on with a small gap for heat gun nozzle, until nearing the end of FC, - adjusting the opening slightly results in a less intense heat to FC, this is an interesting variable. If a bean ends up with some slight tipping, I can significantly reduce or eliminate it next time by opening it up a bit.

After FC has wound down cover comes off for 1 minute then goes back on. - some beans need longer, some shorter to reach just prior to or very first snaps of SC in as close to 5 mins as I can get it. I like this 5 mins to be from rolling FC.

Overall I generally don't deviate to much from my set method, the results are usually pretty good to fantastic / excellent. Where you would have to hunt around and pay a pretty price to find something better from a cafe.

I will also mention that all my taste testing is usually in the form of straight espresso heading toward ristretto range. However I do usually enjoy a piccolo once I am happy.

What a difference almost 2 months makes. New variable HG, temp / roast monitor software and a tile to mostly cover the pan.

I have reduced my batch size down to 300g, I find it much much easier to control and get more repeatable results. Oh yeah and I have to roast more often which is not a bad thing.

Have been playing around a lot with different parts of the roast. My temps are consistant but seem to be 10 to 15deg lower than many other setups.
Drying phase for me finishes around 140 - 145deg, after that browning starts (maillard zone) up to first crack 180 to 185deg. I find playing around with the maillard zone has a big impact on end results, shorter time / hotter = more kick in the acidity/fruity department, too long and I start to get more woody notes heading into baked taste. I generally aim for 4 - 5 mins after the start of RFC to get to the very first signs of SC which is where I usually finish up for espresso, its great being able to keep tight control over this delicate stage.

The following screen shot is a good example of what I aim for now as a " basic standard " roast. Seems to produce a well balanced shot, which is what I am after. Then there is the factor of the machine I am generally using which is BES900 and that has so many parameters that can be adjusted to get the best out of the coffee anyway.

Loving this thread by the way, lots of great input from some experienced roasters.

Being able to control my process to the nth degree from green bean to cup has opened up a whole new world of variables to try, great fun trying all the different SO on BB.

[Dimal]

Hi Mal
Long time no see! Great to see you back :-)

I still check in from time to time mate... Just keep a lower profile these days.

I think I see where you're going. So does this mean that you tend to do faster, harder roasts for harder beans (say Mexicans?) by using a similar technique to normal just with slightly higher temps across the board? This is the kind of stuff I'm wondering.

It's more about maintaining a specific profile rather than speeding up or slowing down the rate, as such. Over time I've discovered that softer beans need slightly less heat input in order to arrive at desired profile, as compared to harder, higher grown varieties which don't appear to be as sensitive. Your profiles look pretty good by the way, not too fast by Corretto standards. There's some very good info on this particular subject from the Willem Boot website here... Have always found the info here to be very enlightening.

The softer beans - stretch it out?

More or less mate, within reason of course. The Willem Boot article above goes into this side of things in good detail.

I guess though there's the difference between sour and acidic?

Indeed there is but I wasn't referring to acidity as such, more in reference to beans that have been roasted incorrectly that leads to genuine sourness in the cup.

Appreciate your input!

Just hope it proves to be of assistance every now and again...

Cheers,
Mal.

[Pete39]

Thanks for the info - much appreciated. The baked roast profile would be great to see.

Pete

[chokkidog]

Hi Pete,

I'm roasting with a drum roaster so my comments do need to be put in context re other types, especially air.
My experience with cupping has been an eye opener for me.

I've done a bit of it with some bean importers from Melbourne and have done a cup roasting workshop with one of them.
All cupping (there), for bean character, suitability for filter or espresso, is done with the same level of roast
i.e. a cupping roast, pulled 30 secs after the end of 1st crack.
Cupping darker roasts was done but mainly to identify roasting faults and not to determine the shot characteristics.
To determine the shot quality and characteristics I have always waited for 5 days and then tried the coffee,
as espresso shots, over the following 5 days.
I have cupped my own espresso roasts but only to determine faults like baking.

I am doing a formal cupping session soon with one of my clients, I'll be deliberately baking a roast.
I could post the profile for that if you're interested.

Cheers

[Pete39]

Hi Chokkidog,

My bad, dunno why I wrote 'expansion' - meant to link to your post with the term but forgot - apologies.

Thanks for outlining your process. I nearly always brew at 93, which is why I mentioned the temp option above, I vary rarely change it.

Re the roast times, I'm assuming you're not using an air roaster? If I go to 12 min for 1st crack on my modded popper, things will be flat (any other modded-popper roasters out there care to comment on this - would be really interested).

I guess what I was trying to say above was, it would be great to learn how a "cupped" espresso roast compares with the espresso it would produce. (I assume this is what the pros can do?) Then I could roast one day, cup the next (ie, not pulled as an espresso, but cupped in the trad sense) and adjust the roast depending on the results. At the moment, I roast, wait around 5 days and then pull a few shots to see if it dials in to something really nice, check how it ages over the next few days, and then make any changes to the roast I think might improve things. So it takes a long time to zero-in on a good roast for a particular bean/blend.

Pete

[chokkidog]

I've heard something about an "expansion wave" that can happen if you dry too fast, but haven't found much detail about that.


Pete

Hi Pete,

Not an 'expansion' but 'evaporation wave'. This simply describes the movement of free moisture out
of the bean. The free moisture is driven out in a 'wave', from the inside to the outside of the bean.
It happens if the drying phase is fast or slow. For well roasted beans tho' we're looking for evenness,
evenness in the initial absorption of heat, the drying phase, the roasting.
Nothing important in itself, just a term.

I understand your difficulty in trying to get the ideal roast. For me it happened by only changing one thing at a time.
First it was achieving a good, balanced coffee from the roast. Then it was establishing the brew temp it worked best at.
So now, for my blends, they are all pulled at the same temp (93°C), if any changes
need to be made they happen in the roast and/or blend ratios.

Single origins are a slightly different matter, what works for one doesn't necessarily work for another but the same process applies.

14 minutes is a bit fast for anything I do, tho' I know some beans work best on a quicker roast.
If I'm roasting to the 'scouts' of 2nd crack then 16-17 mins works best with 1st crack happening @ 12-13 mins from load.

cheers.

[Pete39]

Hope its amazing!!

Pete