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Thread: Ristretto and roast levels

  1. #1
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    Ristretto and roast levels

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Im puzzled.

    Can someone please tell me if a lighter roast that tastes sour as a ristretto will taste any better if it is pulled as a standard shot?

    Ive read that a lighter roast that is too sour for espresso can be fabulous in a coarser grind in French press.

  2. #2
    mwatt
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    Re: Ristretto and roast levels

    Good question. Instinctively I would think it would appear to be more sour as a fully extracted shot, but I have no real evidence for that ;) Something to do with the fact that it seems you extract more of those bitter/sour compounds later in the shot. If youve ever split a shot into three 10ml portions you may know what I mean - the last 10ml is not so pleasant really.

    But then, I really enjoy lighter roasted, highly acidic espresso - which some people call sour.

    But, yes, the lighter roasts can be spectacular brewed via other methods - syphon, drip filter, plunger etc.

  3. #3
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    Re: Ristretto and roast levels

    Depending on how light the roast is (very light - this wont help) you might want to try extracting the shot with a higher brewing temp.

    Otherwise just try it yourself. I dont think it will get rid of the sourness. Dont take my word for it, however.

  4. #4
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    Re: Ristretto and roast levels

    Thanks: tried the higher temps, but still sour. Tried high pressure with adjusted grinds to suit: bitter + sour.

    I enjoy the front-end acidic part of a shot when it is balanced with the central sweetness, but this was definitely a sour central, not acidic, not bitter.

    If anyone reads this who has a Macap M4 stepless, can you give me an estimate of what grind to do a plunger at using a Macap throat number and some object attached to the grinder ::)?

  5. #5
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    Re: Ristretto and roast levels

    Sounds like you might have roasted on a bit light for spro. You might want to try this roast in other brewing methods (with a much coarser grind - like you mentioned) to see if the flavour is more balanced.

  6. #6
    Mal Dimal's Avatar
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    Re: Ristretto and roast levels

    Gday Id...

    For what its worth, I dont think you should be mucking around with the OPV setting on your VBM, I would have thought that the vendor from whom you purchased it would have checked and adjusted this if needed. Set it to 8.5-9 Bar while a normal shot is being pulled (dont use a Blind Filter, this does not replicate real operating conditions) and then leave it there.

    Ditto for the Pressurestat... this should already have been adjusted to the right setting. If it wasnt then you probably should have returned it to where you bought it and asked the vendor to set it properly. Once all this is done, then you are in a position to adequately assess the pros and cons of various roast styles, blends and what have you. If you want to experiment with various brew temperatures on a particular coffee, this is accomplished by varying the water flush volume immediately before locking in the PF and pulling the shot, not by mucking around with the P/stat setting.

    All the playing around with the P/stat may have completely upset the thermodynamic equilibrium of your machine to the point where it is now very difficult to control the quality of any shot you pull. These components are NOT intended for adjusting "on the run" and once set properly should be left well enough alone.

    Going back to the coffee, very light roasts are not really suitable for espresso brewing, much better to use a Syphon, Drip or Pour-over, etc coupled with a coarse-ish grind. Coffee destined for the espresso machine should be roasted close to or past Second Crack and using the CS Membership Card, from about CS8/9 and higher. The "sour" flavours youre picking up on are most likely due to the more acidic nature of the shots being pulled on the VBM.

    Cheers,
    Mal.

  7. #7
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    Re: Ristretto and roast levels

    Quote Originally Posted by Mal link=1223885249/0#5 date=1223899190
    Ditto for the Pressurestat... this should already have been adjusted to the right setting. If it wasnt then you probably should have returned it to where you bought it and asked the vendor to set it properly. Once all this is done, then you are in a position to adequately assess the pros and cons of various roast styles, blends and what have you. If you want to experiment with various brew temperatures on a particular coffee, this is accomplished by varying the water flush volume immediately before locking in the PF and pulling the shot, not by mucking around with the P/stat setting
    The whole temperature management thing on a domestic e61 is a bit of an interesting one. *Its a bit of a tradeoff: if you can easily change the temperature by a simple flush, then youd think that it wouldnt be delivering any temperature particularly repeatably. *If you cant change the temperature by a simple flush, then youd think that the machine is more thermostable in the sense of delivering the same temperature repeatably, but thats cold comfort if you actually want to change the brew temperature. *

    Posts that I have seen have said that increasing the boiler pressure on an e61 by 0.1 bar results in an increase of second crack in brew temperature. *I cant remember what machine(s) this was for, but I suspect that it might be pretty universal. *I had a brief play with a scace device a few months ago in order to work out a temperature management routine at home. *Im waiting to get it again because I didnt really take good notes, but I think that this was roughly true for my machine. *This means that adjusting your pstat is probably a pretty attractive way to change your brew temperature. *Unfortunately, there are a number of reasons why its not necessarily a great idea. *First, pstats are usually quite difficult to access. *Second, pstats are pretty fragile and you run the risk of damaging them if you turn too far one way or slip. *Third, and most importantly, it is possible to electrocute yourself whilst adjusting the pstat setting. *Its up to each person to decide about how they want to adjust their pstat and there is much wisdom behind the advice to leave it alone. *Personally, I have a hole drilled in my machine above my pstat and I actually adjust my pstat infrequently, but always with the power off and with the knowledge that if I screw up I might have to replace the stat.

    The notion that there is a right brew temperature for a given machine that will suit all coffees strikes me as patently wrong, but you can probably set a machine to a temperature that will do OK for most coffees that are out there.

    I was surprised that the scace device showed the cooling flush to be pretty ineffective on my machine, so I use a pressurised portafilter to lower the brew pressure. *I need to get the scace back to see exactly how well this is working.

    There is a definite limit to how much help adjusting the brew temperature can provide. *It sounds like the roast is just too light for espresso. *I cant remember having an espresso brewed at above about 95.5C that tasted good.

    Cheers,

    Luca

  8. #8
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    Re: Ristretto and roast levels

    Thanks. I figured that as soon as I had the cover off I might damage something ;D but it wasnt going to be me - power off, and unplugged.

    Ive contacted the roaster, and at this stage they agree that it sounds like the batch may have been under-roasted and are checking their roast notes. After finally guessing it might be the beans I have tried two other types of beans - one an earlier darker roast of the same blend, which came up beautifully despite its age of 4 weeks, and one from another roaster, which also has come out just fine at the same settings.

    My machine was left at the manufacturers brew pressure setting (more like 11 bar, showing 12 on gauge) when it left the shop. As a result of reading about my experimentation on CS, the sponsor has proactively contacted me to offer a free testing and calibration with a Scace 2, which I have gratefully accepted.

    Funnily enough, if this batch of beans hadnt tasted differently, setting off this experimental day, I probably wouldnt have discovered that the blend (and another) tastes better at ~9 bar. ;D ;D ;D (Laughing at my ignorance.)

    The pressurestat does feel like a tender fitting that could be easily damaged. And similar to what luca discovered about flushing, my little thermocouple only tracked a slow 1*C change at the water directly exiting the shower-screen during a significantly long flush (longer than Ive ever done in my life so I didnt bother measuring it), so I guess my Aussie-spec VBM is even more stable than I initially thought.

    So my machine shall be allowed to rest and settle... until it gets Scaced!

  9. #9
    Mal Dimal's Avatar
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    Re: Ristretto and roast levels

    Behmor Brazen - $249 - Free Freight
    Excellent info from Luca... Thanks mate [smiley=thumbsup.gif]

    As Luca alluded to, unless a machine has been engineered from the ground up to provide a particular thermodynamic equilibrium that allows for relatively simple minor temperature adjustments using flushing volume, youre pretty well going to be out of options. And though it is tempting to adjust the p/stat setting on a regular basis for machines that are very thermally stable, this will in all likelihood result in an early demise of the p/stat and probably to your cost to have replaced, even under warranty. Just something to be aware of....

    For all intents and purposes, the p/stat is intended to be a "set and forget" device that has hopefully been set correctly and within spec for a particular machine. Ive only had access to a few commercial design machines over time and no so-called "prosumer" jobs whatsoever but with the few I had a go at, the brew water temperature could be controlled adequately by varying the flush volumes immediately prior to pulling the shots, hence my recommendation to try this method rather than feeling the need to continually fiddle with the p/stat.

    I guess if youve been lumbered with a thermally stable design, a lot of people would be very envious of you, to say the least. I spose if youre the sort of coffee snob who loves to spend time dialling in a machine to suit all the various bean varieties that you use, a Dual Boiler machine with infinitely adjustable brew water temperature control is the way to go.... All else being the same.

    Thats probably why I particularly enjoyed the level of control I had with my PIDd Mokita a few years ago. I could happily dial the temperature to optimise the flavours I loved from a particular bean, at the drop of a hat with the added advantage that this little machine was also very thermally stable (intra-shot stability) at what ever setting I used. I dont know how this reflects in the use of machines of the ilk of the Expobar Minore II for example as Ive never even seen one, much less used one so maybe an owner of one of these might like to comment.

    Whod a thought that so much could be written about a small brown bean.... Amazing stuff coffee 8-)

    Mal.



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