Posted Wed Jan 23, 2013, 7:59pm Subject: Weight vs. Leveled Volume for Consistent Dose & Distribution
I've been experimenting with my new Rancilio Silvia V3 and Baratza Preciso for a couple weeks, and have been getting okay-to-good but inconsistent results. I'm still dialing in the grinder (I've only had that for a few days), but there's something I'm confused about. I know the goal is to eliminate variables, so I've been working with the same espresso beans (49th parallel Epic Espresso) and the same weight (measured with my 0.1 gram scale) of coffee. Since the roaster recommends an 18g dose for these beans and that's also a common dose in the how-tos and guides I've been reading, that's the dose I've been using (in the stock double basket). But as I've been reading farther back in these and the Home-Barista forums, I've seen several recommendations to fill the basket and then level it without pressure, particularly to help with distribution problems. I think some (if not all) of my inconsistency comes from distribution issues, so I'm definitely willing to give this a try, but it seems to me that this technique would result in an inconsistent dose, because even if I'm weighing and grinding 18g of beans every time, some variable amount of that is going to be removed when I level the basket. Which of these do you think is more important: a consistent weighted dose or a leveled basket for potentially more even distribution?
(And yes of course I know it depends on the machine and the beans and the phase of the moon, but I'm interested in your experience with either or both of these techniques.)
Posted Wed Jan 23, 2013, 9:18pm Subject: Re: Weight vs. Leveled Volume for Consistent Dose & Distribution
It has been quite some time since I had a Silvia, but the stock basket, as I remember it, is small, and 18 grams is a lot of coffee for it. I think that if you dose and tamp as usual, lock the portafilter and then remove it carefully before brewing you will find that the puck has been disturbed by the shower screen. For consistency it is best to weigh the dose. Once you find the maximum mass you can use you can then adjust the grind.
Be aware that two weeks with a Silvia is barely an introduction. She can be less than cooperative, particularly in terms of temperature control.
Additionally, on my website www.EspressoMyEspresso.com, check out this article: 12 - EASY GUIDE TO BETTER ESPRESSO AT HOME. It has a LOT of information, mostly written in plain language with the new home barista and troubleshooting in mind (it will take you a few days to digest it all).
TonyVan Senior Member Joined: 24 May 2010 Posts: 267 Location: Pacific Northwest Expertise: I love coffee
Espresso: GS/3, La Pavoni Grinder: Macap M7K, Rocky Drip: Kone
Posted Wed Jan 23, 2013, 10:26pm Subject: Re: Weight vs. Leveled Volume for Consistent Dose & Distribution
I share your suspicions that volumetric dosing leads to greater variation than dosing by weight.
Although there will be some variation in the density of a given coffee or blend from batch to batch that can throw a weighted dose slightly off (and requiring tweaks in the dial-in), I see far more variation in volume day-to-day from simple atmospheric, humidity and static factors. These "fluffiness" differences disappear when tamped, but if the volume of the dose was compromised by leveling off varying densities, consistency will be impossible.
There are a few techniques out there to normalize a weighted dose to the basket wall height, so "leveling" won't reduce the dose by brushing off. One of these is the "Chicago Chop" (attributed to Intelligentsia) where a thick blade or spatula edge is tapped across the diameter of the basket rim, settling the weighed grounds in the basket until they can be leveled without loss. It's an elegant technique, since the weight rules, vibrations are not so localized as to cause dead spots, top clumps are broken up, and it's very easy to master. Give up trying to find the heavy stainless bar you sometimes see used for this in the Intelligentsia videos - but Peets Coffee sells a 2 Tbsp coffee measure of heavy stainless steel with a dead-straight-edged handle that works perfectly for this technique (and which, to your point, you might never use to actually measure any coffee...)
I think most of those who level their baskets will perform some variation of "settling" first to prevent just the kind of variation you mention.
Posted Thu Jan 24, 2013, 1:21am Subject: Re: Weight vs. Leveled Volume for Consistent Dose & Distribution
fcrn, your Easy Guide to Better Espresso is already part of my massive stack of coffee geek reading, and I've really appreciated all the info there. Thanks for putting together such a comprehensive guide!
It has been quite some time since I had a Silvia, but the stock basket, as I remember it, is small, and 18 grams is a lot of coffee for it.
I do see the impression from the grouphead screw in my puck, but nearly all the Silvia 101 videos I've seen on YouTube show the same thing--one from a well-known espresso parts supply house even points it out as an expected characteristic, and not in a "this is bad/don't do this" sort of way--so I thought it was just a quirk of this particular machine. I'll start with a lower dose and see how it goes, thanks!
Be aware that two weeks with a Silvia is barely an introduction. She can be less than cooperative, particularly in terms of temperature control.
I've been working on temperature surfing for sure. I know I've got a lot more learning to do to get to know Miss SIlvia, but I was hoping to be able to eliminate a couple major variables at the start so I could at least have a baseline to work with.
Posted Thu Jan 24, 2013, 1:25am Subject: Re: Weight vs. Leveled Volume for Consistent Dose & Distribution
TonyVan Said:
There are a few techniques out there to normalize a weighted dose to the basket wall height, so "leveling" won't reduce the dose by brushing off. One of these is the "Chicago Chop" (attributed to Intelligentsia) where a thick blade or spatula edge is tapped across the diameter of the basket rim, settling the weighed grounds in the basket until they can be leveled without loss. It's an elegant technique, since the weight rules, vibrations are not so localized as to cause dead spots, top clumps are broken up, and it's very easy to master. ... I think most of those who level their baskets will perform some variation of "settling" first to prevent just the kind of variation you mention.
But all my research so far has said that any sort of settling or tapping is bad! :) But what you're saying makes a lot of sense. I'll give the Chicago Chop a try and see what I can do about settling the grounds in the basket so I can level it without loss. That would certainly render this question moot, since then it wouldn't be a choice between a consistent weight or a potentially inconsistent leveled basket.
Posted Thu Jan 24, 2013, 4:07am Subject: Re: Weight vs. Leveled Volume for Consistent Dose & Distribution
Dear rhiannonstone, How old does your batch of Epic Espresso get before you receive a new batch? You say your grinder is new, so readjusting the grind as the roast ages is one of the variables yet to be experienced (with this grinder), yes? As you know, as roasts age they provide a 'constant variable'. So even the weight of beans might have to be changed over time to keep to your liking. Also, what methods (besides the palate) do you use to evaluate the packing? Are you able to use a 'naked portafilter' to examine the stream for channeling?
Posted Thu Jan 24, 2013, 9:13am Subject: Re: Weight vs. Leveled Volume for Consistent Dose & Distribution
Tapping _after_ tamping is definitely bad. Before tamping it can help settle the grounds down a little, and even out the pile a bit, which is also the aim of tamping. Stirring the grounds with a needle or fine skewer (Weiss Distribution Technique or WDT) before tamping is also helpful in getting a consistent heap of grounds before tamping if your grinder produces clumps of grounds. This is an alternative to the Chicago Chop for distribution, without affecting the amount of coffee in the PF. It makes more sense to me when single dosing by weight, as all of your carefully measured dose stays in the PF, and also makes less mess in my experience, as you aren't brushing grounds out of the PF to wherever it is that brushed off grounds go to ;) I think the dosing to the top of the PF is really for if you don't want to dose by weight, or don't use a grinder suitable for singe dose grinding, or if you are determining the dose size for a new bean or roast.
Once you've worked out the right dose for your machine, you'll get better consistency if you dose by weight. Generally you need higher weights for lighter roasts and lower for darker roasts. I think the best test for if the dose is the right size is to put a nickel on top of the tamped puck - you should be able to insert and remove the portafilter with only a slight impression from the shower screen pressing on the coin. Using the Chicago chop type technique will put you in the right region for that, and if you weigh the basket before and after filling, you can work out the weight of the dose for next time.
With my Preciso, I find that WDT is helpful, particularly with darker roasts which seem to clump heavily even when transferring them via the grounds bin. My procedure is to grind a fixed weight of coffee (I have the Esatto attachment, but before I had that I single dosed by weight), into the grinds bin of the grinder, then transfer it to the PF with a bit of a yogurt pot to provide a higher lip/funnel, stir with a thin skewer to distribute the grounds evenly and break up any clumps, remove the yogurt pot bit, tap once or twice on the counter to settle the grounds, then tamp and brew. Once I've chosen a dose weight, I only vary the grind as the beans age.
Posted Thu Jan 24, 2013, 10:18am Subject: Re: Weight vs. Leveled Volume for Consistent Dose & Distribution
Buckley Said:
How old does your batch of Epic Espresso get before you receive a new batch? You say your grinder is new, so readjusting the grind as the roast ages is one of the variables yet to be experienced (with this grinder), yes? As you know, as roasts age they provide a 'constant variable'. So even the weight of beans might have to be changed over time to keep to your liking.
I've been getting a fresh batch of espresso every week. I know that bean aging can require small adjustments of weight and grind, but since the variations I'm experiencing between shots are major rather than minor, I assume it's a more significant factor than bean age, and thought it would make sense to get a basic technique down first.
Also, what methods (besides the palate) do you use to evaluate the packing? Are you able to use a 'naked portafilter' to examine the stream for channeling?
I don't yet have a naked portafilter--this is a new setup, and I haven't bought a second pf or been able to part with my current one long enough to send it to the machine shop yet--but I've been evaluating shots based on extraction time and volume, crema color, and of course taste. The reason I suspect my distribution/packing needs work is that the espresso tends to come out much faster from one portafilter spout than the other.
Posted Thu Jan 24, 2013, 10:24am Subject: Re: Weight vs. Leveled Volume for Consistent Dose & Distribution
dyqik Said:
Tapping _after_ tamping is definitely bad. Before tamping it can help settle the grounds down a little, and even out the pile a bit, which is also the aim of tamping. Stirring the grounds with a needle or fine skewer (Weiss Distribution Technique or WDT) before tamping is also helpful in getting a consistent heap of grounds before tamping if your grinder produces clumps of grounds. ...
With my Preciso, I find that WDT is helpful, particularly with darker roasts which seem to clump heavily even when transferring them via the grounds bin. My procedure is to grind a fixed weight of coffee (I have the Esatto attachment, but before I had that I single dosed by weight), into the grinds bin of the grinder, then transfer it to the PF with a bit of a yogurt pot to provide a higher lip/funnel, stir with a thin skewer to distribute the grounds evenly and break up any clumps, remove the yogurt pot bit, tap once or twice on the counter to settle the grounds, then tamp and brew. Once I've chosen a dose weight, I only vary the grind as the beans age.
This makes sense and is helpful, thanks! I've actually got a bunch of (clean, unused) dissecting needles in my craft drawer, so I've got no excuse not the give the WDT a try as well.
Posted Thu Jan 24, 2013, 11:41am Subject: Re: Weight vs. Leveled Volume for Consistent Dose & Distribution
So lowering the dose to 16g and using the WDT has already helped a lot! I got a much more even extraction for my morning espresso--and, whaddyaknow, the pf was a lot easier to lock in without so much extra coffee in the way. :)
Symbols: = New Posts since your last visit = No New Posts since last visit = Newest post
Forum Rules: No profanity, illegal acts or personal attacks will be tolerated in these discussion boards. No commercial posting of any nature will be tolerated; only private sales by private individuals, in the "Buy and Sell" forum. No cross posting allowed - do not post your topic to more than one forum, nor repost a topic to the same forum. Who Can Read The Forum? Anyone can read posts in these discussion boards. Who Can Post New Topics? Any registered CoffeeGeek member can post new topics. Who Can Post Replies? Any registered CoffeeGeek member can post replies. Can Photos be posted? Anyone can post photos in their new topics or replies. Who can change or delete posts? Any CoffeeGeek member can edit their own posts. Only moderators can delete posts. Probationary Period: If you are a new signup for CoffeeGeek, you cannot promote, endorse, criticise or otherwise post an unsolicited endorsement for any company, product or service in your first five postings.
= No New Posts since last visit 