Chemex 3-6 cup & Hario V60 02 test, alternating filter papers.

A couple of posts back I got some unusual results (compared to contemporary brews) from a Hario V60 02 dripper with a CBI style, drip brew method. I only had Chemex filter papers handy & I wondered whether the paper, or the V60 dripper was responsible for the wider deviation in extractions with that method, compared to Kalitta Wave, Westmark 2-hole plastic (Melitta style) brewer & a Bonavita Immersion dripper (the latter used as a pourover brewer, rather than as an immersion brewer).

It is important to remember that any of these brewers can produce consistent cups with good technique & dialling in. For the purposes of this test however, I was more keen to see how the brewers & papers behaved with a very consistent, but basic technique, with no changes, nor dialling in from the previous tests.

All filter papers were bleached white variants, the V60 papers were made in Japan.

10 brews for each brewer & paper combination were carried out, 40 brews in total. These 40 brews had an average extraction yield of 18.6% and a SDev. of 1.49%EY, the 40 brews spanned a 5.7% range of extraction yields (15.7% to 21.4%).

Chemex & Chemex paper/V60 & Chemex paper vs. V60 & V60 paper/Chemex & V60 paper: showed no significant difference as being due to the paper used, in neither time (p=0.259), nor extraction yield (p=0.097).

Chemex paper & Chemex/V60 paper & Chemex vs. Chemex paper & V60/V60 paper & V60: showed a significant difference in both time (p=0.000) & extraction yield (p=0.003). So it looks like the brewer makes a bigger difference than the paper filter used.

Chemex vs Hario 40 brews

Running an ANOVA on the 4 brewer & paper combinations showed that there was a difference in both brew time & extraction yield.

Further investigation showed no significant difference in extraction yield between V60 with Hario paper, V60 with Chemex paper, or Chemex with Chemex paper. F(2,27)=0.909, p=0.415.

Chemex with V60 paper did show a difference in extraction yield when run over all 4 conditions. F(3,36)=5.960, p=0.002.

Hario V60 brewer with Chemex papers, or V60 papers: Whilst there was no difference between the Hario V60 brewer with either paper, in terms of extraction yield (p=0.743), there was a difference in brew time (p=0.000) with the Hario paper taking, on average 18 seconds less to hit the same EY. The V60 brewer did, however, show a lower SDev. (1.10%EY) with the Chemex paper than with the V60 paper (SDev. 1.43%EY).

Chemex brewer with Chemex papers, or V60 papers: There was no significant difference in brew time between Chemex with Hario paper & Chemex with Chemex paper (p=0.768), but there was a difference in extraction yield (p=0.029). The Hario paper in the Chemex brewer resulted in the highest & most consistent extractions (average 20.0%EY, SDev. 0.95%) compared to Chemex paper (18.6%EY, SDev. 1.57%).

Chemex paper with V60, or Chemex brewers: There was no significant difference in extraction yield (p=0.239), but there was a difference in brew time (p=0.000), with the V60 brewer & Chemex paper taking 28 seconds less on average, to hit a similar extraction. The V60 brewer did, however, show a lower SDev. (1.10%EY) than the Chemex brewer with the same paper (SDev. 1.57%EY).

Hario V60 paper with V60, or Chemex brewers: Again this showed the V60 paper & Chemex brewer combination to be able to achieve a higher (20%EY, versus 18%EY for the Hario brewer) & more consistent extraction yield (0.95%SDev, versus 1.45% SDev for the Hario brewer), whilst stretching out brew time by an average of 48 seconds.

Whilst the brew method used, in itself might not follow popular methods, it does seem to reinforce the need to pour in a controlled manner & not allow a large body of liquid to sit above the bed for the Hario V60 with either paper, or the Chemex brewer with Chemex paper.

This test, along with another I conducted with a Bartlett 3-hole (Melitta style) truncated cone, also seems to reinforce Peter Guiliano & Thompson Owens’ observations, that the truncated cone brewers, with a single small drainage hole (Bonmac, Melitta, Bonavita) are able to extract well with a more basic, fill & forget type technique. The Kalita Wave also seems to fall in this category, despite having 3 holes (the holes in my steel 185 version are much smaller than the drainage holes in the other brewers).

My take-aways from this are:

  • Use a goose-neck pouring kettle with drip brewers that have a large and/or numerous drainage holes. Pulse pouring and/or grind adjustments to control flow are more critical for these brewers in order to maintain target extractions.
  • The Kalita Wave & Chemex 3-6 cup, with V60 paper, can produce ‘gold cup’ & consistent extractions with  a regular kitchen kettle. As can the truncated cone brewers with a single, or maybe two, small drainage hole(s).

Purely subjectively, the Chemex brewer & Chemex paper combination achieved the lowest average preferences in this test, but in fairness none of the 4 combinations tested here hit my typical preference, in the context of this experiment.



Manual brew method consistency check.

Is it you, or the, or the recipe, or the brewer itself that is inconsistent?

My recent brew logging excercises pretty much suggest that it is us. Several drip brewers & immersion methods are showing very similar standard deviations in extraction yield, where the same recipe, brewer, grinder & grind setting for that method are used.

Without the need for more in-depth statistical analysis, it is becoming apparent that if you carry out 10 brews, each with a different coffee (assuming all fall within your typical roast preference range), changing nothing but the coffee, a span of <3% extraction yield across those 10 brews is suggestive of 95% of them landing within a 4% EY span. A normal distribution for “Gold cup” brews, if those 10 brews span <3%EY, between 18-22% EY?


CBI Style Drip Brews: Bonavita Immersion Cone, Westmark 6-Cup Cone, Kalita Wave 185, Hario V60 (with Chemex paper).

To recap, all brews were the same dose (13.5g), the same brew ratio (58g/l), the same grinder setting (1+10 on a Made by Knock, Feldgrind).

10 brews for each brewer, the first & only attempt for a different single origin for each brew, in each brewer. Brew water was weighed out into a kettle then poured at a rolling boil, aiming for 232g total brew water added in one, quick (~5 seconds) fill, after blooming.

The ceramic Bonavita Immersion brewer was preheated, filter paper rinsed as part of the preheat. The other brewers (being plastic, or steel) were not preheated, nor were papers rinsed. The Bonavita bloom time ended up at 105 seconds – 90seconds plus fill, then a stir at the surface & open the valve. The other brewers were bloomed for 90seconds, then brew water added, a stir at the surface at completion of fill.

  • Bonavita Immersion cone: Average EY was 20.6%, SDev of 0.61, min. to max. EY span of 1.9%.
  • Kalita Wave 185 (steel): Average EY was 20.2%, SDev of 0.87, min. to max. EY span of 2.4%.
  • Westmark 6-Cup (plastic): Average EY was 20.5%, SDev of 0.76, min. to max. EY span of 2.7%.
  • Hario, plastic V60 02, with Chemex paper: Average EY was 18.4%, SDev of 1.63, min. to max. EY span of 5.6%.

I had run out of Japanese V60 02 papers, hence the use of the Chemex papers. The results with the V60 02 were significantly different to the other three (p=0.000). There was no significant difference between the Bonavita, Kalita Wave 185 & Westmark (p=0.477). These three brewers combined (n=30) had an average EY of 20.4%, SDev of 0.75 & a min. to max. EY span of 2.7%.

The Hario V60 02/Chemex paper combination was the only brewer to drop below 18%EY extraction (4 of 10 brews, readings of 16.3%, 17.1%, 17.5% & 17.5%EY respectively). Highest EY for the Hario was 22%. The other brewers never dropped below 19.3%, nor exceeded 22%EY.

Maybe a finer grind would have brought the Hario into range, the average EY was certainly lower than the others?  Maybe the thicker, more porous paper allowed more of a bypass effect? Oh well, looks like I’ll be buying the V60 02 papers after all, to see if the difference follows the brewer, or the paper…


CBI Style Drip Brews in the Bonavita immersion cone, additional…

I expanded the brew method over 10 brews, no changes other than using a different single origin coffee for each brew. Each brew recorded was the first brew with that coffee, no dialling in of any sort…

Brew Method Consistency Bonavita CBI style drip

I then thought I’d compare those 10 drip brews with 10 French press brews. Again, the same grinder, grind setting & method for all the French press brews.  No changes between the French press brews beyond using 10 different single origin coffees, one for each brew. Note: I did not use the same 10 coffees in both brewers, so it’s not an absolute like-for-like comparison (plus there are couple of other aspects that can skew results between these scenarios), nevertheless, I found this interesting…


Brew Method Consistency French press.jpg


CBI Style Drip Extractions With Bonavita Immersion Brewer.

CBI style Bonavita drip chart

I have been very much enjoying drip brews made in the Bonavita immersion cone of late. It strikes me that hand pouring for drip can bring with it some inherent inconsistency, even if you’re very regimented, so the Bonavita can maybe help there (especially if you don’t want to be bothered with being very regimented), by using the shut-off valve feature?

Hand pouring, in pulses and/or spirals, can then be replaced by dumping all the boiling brew water, in one quick pour, into the brewer then open the valve. No gooseneck pouring kettle is required. Adding the brew water like this seems a bit counter-intuitive today, but it was previously used by the Coffee Brewing Institute (CBI) back in the 60’s. Back then, Wilbur Curtis made “Gold Cup” manual drip brewers that contained the coffee dose in a compartment, that prevented the grounds from completely mixing with the brew water. The long pre-wet in the method below seems to help even things out & replaces the grounds compartment idea, as the water-logged grounds should sink very quickly to the bed.

If you’re enjoying super consistent, hand poured, drip brews then there’s probably little point in reading further.

1. Boil the preheat water, grind your dose. Add preheat water to Bonavita (valve shut) & filter paper.

2. Make sure the brew water kettle is empty, shake out any drips, then weigh your brew water into the kettle. If you are making smaller brews, then a compact/travel kettle might be best for brew water (I have been using 244g of brew water in the Sage compact, just about the “Minimum” line on the kettle). Don’t destroy your kitchen kettle by trying to boil less than the minimum water volume. I have been using my main kitchen kettle for preheating & rinsing, then the smaller, compact kettle, for brew water.

 3. Drain the preheat water from the Bonavita brewer (a couple of taps to shake out any residual water), start the brew water boiling & weigh out the ground coffee dose.

 4. Shut the Bonavita valve, add dose (13.5g in my case), start timer & bloom with 1.5 times dose weight in boiling brew water weight. Stir to make sure dose is well wetted (carefully, so as not to tear the paper filter). Put the brew water kettle back on the hob/power supply.

 5. At ~1:15 (with my kettle, tune timings for 1:30 fill) re-boil the brew water & at 1:30 quickly dump the remainder of boiling brew water into the Bonavita (taking care not to splash it around if making larger brews), shaking out any drips, 1 quick stir of the surface & open the Bonavita valve at 1:45.

6. Note the time at which you see the water drain from the bed, then give the brewer a couple of taps & leave another 30 seconds, or so, for drips to drain. I have been seeing a dry bed around 3:05 (+/-15 seconds) for quantities above.

So far, my brews are landing +/-1%EY (VST Coffee Tools, drip mode), 5 different coffees, light to medium dark, from 3 different roasters, no change in grind setting (1+10 on a Feldgrind).
CBI style Bonavita drip data
I wouldn’t suggest buying a Bonavita immersion cone, just for this purpose, but it might be worth a try, if you already have one.

EDIT #1 – Different kettles will have different outputs (due to different dimensions & rates of evaporation), given the same weight of brew water added. Adjust your initial brew water weight based on the final output of the brewer. For instance, here I am aiming for 232g of total brew water in the brewer & a beverage 15x the dose weight, or 203g from 13.5g.

EDIT #2 – Whilst the shut-off valve on the Bonavita gives a little more control in stopping your bloom water from dripping through to the cup, or nailing a given output from the brewer, I am finding I still get pretty good consistency using this same basic method with straightforward pourover cones (Melitta style, Kalita Wave).

Cupping/immersions & slurry temperature drop.

Cupping Temp Drop DataFive cupping/immersion methods were tried, 3 cups per method, coffees rotated so that each method got a reasonable spread of extractions.

Grind setting was kept constant for all cups (approx. 500 microns – a little coarser than my normal grind, I suspect that this clamped typical extractions in this case), as was brew water (Volvic, poured whilst at a rolling boil). Vessels were not preheated.

Temperatures were taken at fill (~45seconds from first contact with brew water), 4 minutes, 9 minutes and 15 minutes (where applicable).

SCAA cupping protocol suggests the slurry should be approaching 71C at 8 to 10 minutes. The only way I could get near to this was by covering cups (the SCAA protocol also mentions the requirement for lids for cupping vessels).

Cupping temp drop chart_zpszw8q8mwc

I didn’t attempt pouring water at less than boiling, as brew temperature at fill was barely over 90C in most scenarios. I guess the initial temperature for the ceramic lid covered brews dropped as the ceramic lid will have absorbed some heat, as well as the bowl itself. Improved heat retention for the rest of the brew time seemed to prevent this being an issue compared to the other methods.

The thin glass of the French press & its lid seemed to rob less heat from the steeping slurry. Preheating ceramic bowls & lids may be advantageous. Strangely, the SCAA has just removed the suggestion to use 5-6oz rocks glasses, for cupping, from their protocol.

Purely subjectively, all methods produced tasty cups, if the coffee was soluble enough. A couple of the 9 minute brews were plain under-extracted.

There was typically nothing to break after 15 minutes. If you want to enjoy the break, don’t uncover/break all the cups for that sample.

The 15 minute steeps had a higher average preference despite comparable TDS readings for methods #3 & #4 and the 9 minute steeps (methods #1 & #2), but I had no clear preference between the three 15 minute scenarios, in the context of this rather limited sample. I do not take this to mean that the TDS or EY has little bearing on my preference, rather that these cups typically did not hit a high preference range for me.

Whilst the most soluble coffee used was tasty via all methods, few of the cups hit my typical target, which is usually achieved at approx. 400 micron median grind, 18 to 19:1 brew ratio for 20 minutes, covered steep ending over 70C & 22%+ extraction yield (calculated via VST Coffee Tools, immersion/cupping mode).

My takeaways here are:

  • Water at less than boiling, poured into a non-preheated vessel, is going to have a low brew temperature…and it’s only going to keep dropping.
  • Thin walled, glass vessels retain higher brew temperatures.
  • Cover whilst steeping.
  • Grind size for as full as possible extraction is pretty fine, medians dovetailing with coarse espresso & finer end of drip may be needed. (Beware – too fine, or too many fines may prevent efficient wetting with just a pour, this can be observed with a glass vessel.)





Practical Hand Grinder Comparison, Based on Drip Brewed Coffee.

Hello, my name is Mark and I have a problem…I bought my first one out of necessity, just to grind my beans…My coffee didn’t taste great, so I naturally assumed it was the grinder’s fault, so then I bought another & guess what, my coffee got a bit worse, then it got a bit better. Encouraged by this chain of events, I figured buying another hand grinder would result in a further escalation in my brewing prowess…& then another…& another…So, to date, I have probably owned 15 or so hand grinders. I usually have about 10 at any one time. All have small conical burrs and are hand held devices, rather than bench top.

This situation probably won’t get any worse, nor any better – they’re relatively cheap, portable, they don’t take up much space & don’t need much in the way of care & feeding. People have asked me, “Why do you need 10 hand grinders [with small conical burrs]?”. It’s a reasonable question, so here is the honest answer…”I don’t, nobody does.”.

Some have advantages over others (grinding speed, ease of grinding, weight & size) but essentially, they do very much the same thing.

Over the last couple of months I decided to try and establish whether, given a scenario reasonably in line with all of the grinders’ attributes & reasonable expectation, I could learn anything about their respective qualities.

At this point it should be noted that the grinders discussed are in good working order, I have owned grinders with visibly bent shafts & a permanent burr gap of whole millimetres at one side of the burr, that were unable to make particles smaller that 3mm across, at any setting. I am not considering defective models, nor those that are obviously very poorly designed in this post.


The Method.

I typically drink out of a 5oz cup, I tend to prefer paperless brews, so for all brews I used my Hario Cafeor paperless V60 filter, a Hario drip stand with 0.1g resolution scales under the drip tray to measure beverage weight. The whole kaboodle sitting atop Salter 1g resolution scales for measuring the brew water weight.

Coffee doses were weighed out to 9.00g +/- 0.02g (this accuracy might sound extreme, but this is the quickest & easiest part of the process to get spot on).

Brew ratio was 9.0g of coffee to 150g of brew water. 30 second bloom with 15g of brew water (350g brew water heated in the kettle total, bloom one minute off boil after preheating pouring kettle & filter cone).

Different coffees were used throughout the evaluation, reasonably divided amongst the grinders.

The grinders were dialled in, by taste, to aim for a post-bloom flow rate around 1g/sec., or 133g of beverage in 2:43 total brew time. Averaged standard deviations in brew time overall were 14.24 seconds & 0.114g/sec.

The pour regime was tailored to each grinder to maintain this flow rate & avoid detrimental effects such as excess silt in the cup. For example, the Lido 1, Lido E were able to achieve this in one filling pour after the bloom. The Zassenhaus Panama needed an overall coarser grind to mitigate silt in the cup, so needed three pulses of 45g every 30seconds, or four pulses of 34g per pulse every 25 seconds to match the brew time & flow rate of the others. All grinders were given a few dial-in brews prior to recording observations.

Brew time was measured up until no standing brew water was visible above the grounds bed, then additional time (not counted) was allowed to let drips cease.

All cups were subjectively scored on a 9point scale, based on the quartermaster’s hedonistic scale, but adding a decimal point to the scale as scores tended to be clustered in the upper third.

10 dialled in brews per grinder were assessed.


The Grinders.

Made By Knock Feldgrind (late 2015 model with black burrs), set to 2 full turns from tightest setting, plus “4” or “5”. Steel burrs.

OE Lido 1 (discontinued, but a good yardstick as this grinder pretty much set the standard for a modern day brewed coffee, hand grinder), set to 1/4 turn out from marked zero, the first setting that allowed totally free & silent turning of the handle. Steel burrs.

OE Lido E, set to 11/16. Steel burrs.

Porlex Tall (my first grinder & one that I will always have a use for), set to 10 clicks out from lock up. Ceramic burrs.

Rhino, set to 5 clicks out from lock up. Ceramic burrs.

Zassenhaus Panama, set 4 clicks out from the first sign of burr rub. Steel burrs.


Somewhat Subjective Observations.

The most obvious relationship relating to higher scoring beverages, was a higher consistency of brew time & subsequently, post-bloom flow rate. The highest scoring brews were between 0.87 & 1.15g/sec. Whilst some of the lower scoring brews were also in this range, they spanned 0.79 to 1.29g/sec. (Typically 3-4g would land in the cup after blooming, but my average flow rate was calculated on beverage weight/brew time, post bloom.)

There was not a clear difference between the grinders, in the context of the brew method & recipe used, in relation to my preference towards the drinks made.

Hand grinder test flow v score

This doesn’t mean that all the grinders made ‘the same’ tasting drinks, just that over 10 brews per grinder, over a selection of beans, they averaged out pretty much the same.


More robust observations.

There was no significant difference in brew ratio, beverage weight, brew time, nor flow rate. See averaged values over 10 brews per grinder below:

Hand grinder tests ANOVA

So, are they all just as “good” as each other, with just price as the decider? No, not really.

The steel burr grinders were significantly faster to grind the 9.0g dose weight (20-40 seconds typically, compared to 50-80 seconds for the ceramic burr models). Grinding doses in excess of 20g on the ceramic burr grinders really becomes a chore. I would certainly recommend any of the steel burr grinders for doses in excess of 15g & consider them good value for money, even at three to four times the price of the ceramic burr models.

The Feldgrind & Lido E will grind as fine as you could ever need for brewed coffee, however the coarser finishing area of the Zassenhaus Panama makes fine grinds a challenge. It certainly grinds fine enough for drip & French press, but I would have reservations if trying to use it for finer Aeropress, Clever Dripper & Turkish brews.

Fineness for typical brewed methods is not an issue for the Porlex Tall, nor Rhino, however they produce a lot of fine particles at coarser settings. I wouldn’t recommend the Zassenhaus Panama, Porlex, or Rhino for permanent filtered immersion brews that drain through the bed, such as Sowden, or Brewt.

The Lido grinders will hold at least 60g of beans and grind the lot in one go.

The MBK Feldgrind holds ~36g.

The Zassenhaus Panama will hold ~20g of light/medium roasted beans, it is also very quick to grind, so 2 loads totalling 40g is no problem (but keep your pinky finger wrapped around the catch cup, as this is only an interference fit & has a habit of dropping off).

The Rhino & Porlex Tall hold more beans than you would sensibly want to grind in one go, but are certainly adequate for most brew methods utilising smaller doses.