Fine grind/course grind blend...How To?

[reubster]

Hi Yall,

Whilst most beans Ive roasted seem to fall within a predictable "espresso grind-range window" some [eg Indian Tiger Mountain & Bali Gunung Agung] fall right outside and seem to require extremely fine grind settings.

I recently seperately roasted some ElSalvador San Emilio Farm and Bali Gunung Agnung, thinking a 50/50 mix might make a pretty good combination, but I dont think Ill be able to blend them due to the significant differences in their required grind settings.

If I grind the BGA on the appropriate setting for the SEF, Ill get a 5 sec pour
and conversely,
I could perform a backflush if I ground the ESM on a suitable setting for the BGA.

Setting the grinder midway between both settings will still choke on the ESM and gives a 15sec gusher for the BGA.
So I am yet to try blending them.

So what does one do/How can you make this work? .....at the moment Im drinking SOs.

[mwatt]

Re: Fine grind/course grind blend...How To?

Probably someone else can answer better, but Id suggest you blend a bit, then dial in your grinder as you would for any SO... find the grind setting that means the shot pulls in the correct time.

I always find Monsooned Malabar needs to be ground finer than a lot of other beans, but Ive used it in a blend with no dramas.

Just dial in for the blend...

[reubster]

Re: Fine grind/course grind blend...How To?

Thanks mwatt

Youre probably right, I should just do it, and I will give it a go,

but I cant get around the THOUGHT that the shots will contain underextracted BGA and over extracted SEF.

[mwatt]

Re: Fine grind/course grind blend...How To?

but I cant get around the THOUGHT that the shots will contain underextracted BGA and over extracted SEF.

I know what you mean. Blends spin me out.

Even just the fact that really the chances of each shot being 50/50, or 40/30/20/10 (or what even other percentages youre blending) have got to be pretty limited. So really, every shot from a blend will taste a bit different... wont it?

[robusto]

Re: Fine grind/course grind blend...How To?


Make sure the beans are mixed well before putting them in the hopper.

The first extraction may, of course, be too coarse or fine, and then its a mater of adjusting accordingly.

From then on, you may have to make slight corrections to take into account the humidity, aging of the beans etc-- as you would for a SO.

[reubster]

Re: Fine grind/course grind blend...How To?

Ok
So Ive been playing around with this and Im not happy with the results.

Im using 50:50 blends which PURPOSELY include a bean requiring a very fine grind and a bean requiring a relatively course grind.
While these blends have not been chosen on flavour profile, I would have thought that the "taming" South Americans would have been suitable partners for the "greater bodied" Indians.

All beans were roasted seperately and taken to the onset of 2nd crack and rested for 8 + days.
All beans were tried seperately as SOs to establish quality of roast/taste and were all fine.

Blend 1. Indian Monsoon Malabar & El Salvador San Emilio Farm
Blend 2. Indian Tiger Mountain & Columbian Popayan Supremo.

Once dialed in, I am getting great pours, [those Indian coffees give a great body and crema] but I am disappointed with the flavour.
In either blend there is:

1. An underlying over-extracted flavour in the cup
2. The blended shots have a thicker [almost chewy or Turkish] mouthfeel
when compared to the SOs [I dont mind this though]
3. There is an underlying muddiness to the shots that masks the
character of the SOs.

In fact, these fine/course blends are quite reminiscent of the shots I was getting with my grinder before I replaced the old worn burrs.
The worn burrs produced a grind with perhaps a 20% content of fines/dust. In the cup, these shots always tasted muddy and over extracted in a similar way to the blends above.

My conclusion is that within either blend, the South American beans are being too finely ground and thus being over extracted.

What are your views?

[mwatt]

Re: Fine grind/course grind blend...How To?

My conclusion is that within either blend, the South American beans are being too finely ground and thus being over extracted.

What are your views?

I dont really understand how that could be the case.

Bear with me:

Over-extraction occurs when water is in contact with the grinds for too long, and so too many solubles are extracted, yes? But if your shots are within the parameters of a good pour, how can this be happening? Because theyre spending the same amount of time being extracted as if you were pulling a SO shot.

Unless its completely dependant on surface area of the grinds?

Are you sure it couldnt be the blends? To my mind the San Emilio 50/50 with Malabar would just be overpowered.

[Viviane]

Re: Fine grind/course grind blend...How To?

Im with Michelle on this. It seems to me that the reason that too finely ground beans cause over extraction is not because of the size of the particles. They are more closely compacted in the PF and so it takes longer for the water to pass through them. Hence they extract for longer. If you are getting the normal extraction time, then over extraction wouldnt be happening.

I would be blaming the blends here - you did say that you didnt create them on flavour profiles.

[Dimal]

Re: Fine grind/course grind blend...How To?

I really believe that youre chasing ghosts Reubster.....

As both Michelle and Viviane have pointed out, the blends youve chosen arent ones I would have chosen either, to make judgements about in the cup impressions but I can see where youre coming from. What ever the make-up of your blend, the quality of the shot is dependent on the same factors that govern the outcome of Single Origins.

The same bean roasted to varying milestones will have varying grind settings to achieve pours within the ideals of the Golden Rule but when you create a blend using the same beans roasted to different profiles, the resulting dialled-in shot(s) will require slightly different grind settings to shots pulled from the individual roast batches of the same bean. I have conducted experiments with a number of PNG, Central Americans and Colombian beans (a fair while ago) and never experienced the muddy sensation you refer to or other off tastes. In fact some of my favourite blends are of the same SO beans roasted to different profiles and blended post-roast.

So long as you are dialling-in your blends to ensure as close to ideal pours as possible, i.e. stopping the shot before blonding starts or at the first signs of blonding, then Im sure you will avoid either under or over extracted segments of the shot in toto. So long as the Brew Pressure, Temperature, and Shot Duration are correct, I cant see that over/under extraction can occur within the homogeneous mass of a tightly packed coffee puck. Sure, if the pour is too quick or too slow, channelling is observed, uneven extraction due to an unevenly tamped coffee puck, etc etc.... then yes, you can definitely taste that something is off in the cup but so long as ones taste-buds are happy, then theres nothing to be concerned about..... Let your palate be your guide Reubster ,

Mal.