Yama cold drip parameters?

Coffee preparation techniques besides espresso like pourover.
pacificmanitou
Posts: 1263
Joined: Wed Feb 01, 2012 2:20 pm
Real Name: Brandon
Equipment: Sama Lusso, Arrarex Caravel, Pharos 889-V, Baratza Vario, Hottop B
Location: Fairborn, Ohio

Postby pacificmanitou » Fri Aug 09, 2013 4:53 pm

I have begun setting up my cold dripper, but it seems to run fast. Its set for 40 drips a minute with 60 grams of coffee ground for coarse drip. An hour and a half in, I have about 500 ml brewed. Is this too fast? How long should this run?
LMWDP #366

chang00
Posts: 543
Joined: Wed Jul 23, 2008 6:25 pm
Real Name: Henry
Equipment: Too many
Location: WCR

Postby chang00 » Fri Aug 09, 2013 9:03 pm

It seems like you have the 5-person version. The rate is about right for 500ml. After brewing, place the brew in refrigerator for another 1-2 days before serving. It actually tastes better after some further resting.

lever espresso machine parts, manual grinders
User avatar
Bob_McBob
Posts: 1863
Joined: Wed Jan 21, 2009 7:12 pm
Real Name: Chris Birkett
Equipment: Yes
Location: Waterloo, ON, Canada

Postby Bob_McBob » Sun Aug 11, 2013 12:16 pm

With basic drip tower designs like the Yama, the flow rate is set by the bed of coffee if you are using it properly. For an even extraction, you need to maintain a column of water above the coffee. After initial saturation, periodically adjust the water valve drip rate to match the brewed coffee drip rate. The coffee drip rate can be adjusted by changing grind and dose, just like any other method. It's basically like watching a perfect pourover brew in slow motion.

There are far too many videos of people using drip towers improperly. Typically you will see a bed of damp grounds with an incredibly slow drip, and advice about how it can take 12 hours to brew a batch. If you do it this way, you are just dripping water down the centre of the bed of coffee and getting an incredibly uneven extraction. You're also wasting a huge amount of time, because you can easily get a proper extraction with a 60-90 minute brew time.

Some newer designs like the Alley600 have the clever addition of a second valve so you can independently set the coffee drip rate and match it to the water drip rate. This opens up some more brew parameter possibilities. Unfortunately, while they are reasonably priced in Korea (~$290), the helpful addition of a local "distributor" (who stocks no spare parts) drop shipping straight from the manufacturer significantly increases the price (around C$500 in Canada, £395 in the UK, and so on). With these brewers you also often see a two part water reservoir to eliminate the flow rate change as the water level drops.
Chris

pacificmanitou
Posts: 1263
Joined: Wed Feb 01, 2012 2:20 pm
Real Name: Brandon
Equipment: Sama Lusso, Arrarex Caravel, Pharos 889-V, Baratza Vario, Hottop B
Location: Fairborn, Ohio

Postby pacificmanitou » Sun Aug 11, 2013 3:34 pm

Bob_McBob wrote:With basic drip tower designs like the Yama, the flow rate is set by the bed of coffee if you are using it properly. For an even extraction, you need to maintain a column of water above the coffee. After initial saturation, periodically adjust the water valve drip rate to match the brewed coffee drip rate. The coffee drip rate can be adjusted by changing grind and dose, just like any other method. It's basically like watching a perfect pourover brew in slow motion... You're also wasting a huge amount of time, because you can easily get a proper extraction with a 60-90 minute brew time.


I have finished two extractions so far, both at five hours. While this is in the normal range according to convention, should I speed it up?
LMWDP #366

Nuprin
Posts: 167
Joined: Thu Oct 15, 2009 1:19 pm
Real Name: Mike
Equipment: Linea 3 Group, Quamar M80, Mazzer Robur, Compak K10WBC, Baratza Vario & Virtuoso
Location: Raleigh, NC

Postby Nuprin » Thu Aug 15, 2013 10:51 am

Have to disagree. We have 2 large Yama brewers and 1 small brewer at the shop. I experimented with multiple grind settings, drip rates, water temperature and such. We use a very coarse grind, basically a little finer than Press. Our drip rate is about 1 drop per second or two. The problem with using a finer grind is that it will clog and you get very little output out the middle section into the beaker below. The key is to pre-wet the bed of coffee so that all the grounds are saturated before placing the filter on top and starting the drip.

Darker roasted coffees using this process usually resulted in a good cup the next day. However, lighter roasted coffees like Africans were OK the first few day but by giving it 5-10 days to age, the coffee became amazingly delicious; full of fruit notes and smooth.

I've also been to Blue Bottle and tried their ice coffee and was not impressed; too strong, bitter and over extracted. Tried Toddy and Japanese iced coffee method as well and found the aged slow drip still produces the most clean and unique flavors of any method.

User avatar
Bob_McBob
Posts: 1863
Joined: Wed Jan 21, 2009 7:12 pm
Real Name: Chris Birkett
Equipment: Yes
Location: Waterloo, ON, Canada

Postby Bob_McBob » Thu Aug 15, 2013 11:08 am

I'm not sure what you're disagreeing with. A grind so fine there is no output from the drip tower is obviously not going to work. If your bed of coffee is not immersed in water at all times then you are just masking the uneven extraction by pre-wetting the grinds. The paper filter on top does not spread the water out over the surface of the grinds in any significant way. If you start with a dry bed of coarsely ground coffee and a very slow drip rate (note that 60 drips/minute is not slow), you can clearly see a cone of water spread out from the top of the bed to the bottom, missing a significant portion of the grinds.
Chris

Nuprin
Posts: 167
Joined: Thu Oct 15, 2009 1:19 pm
Real Name: Mike
Equipment: Linea 3 Group, Quamar M80, Mazzer Robur, Compak K10WBC, Baratza Vario & Virtuoso
Location: Raleigh, NC

Postby Nuprin » Thu Aug 15, 2013 2:24 pm

For an even extraction, you need to maintain a column of water above the coffee


I don't have to maintain a column of water above the coffee to get good extraction. No, it's not a perfect immersion, but the coffee stays saturated about 2/3 to 3/4 of the way up the column. When we've allowed the water to go above the top of the bed, the final extraction ends up more bitter.

There are far too many videos of people using drip towers improperly. Typically you will see a bed of damp grounds with an incredibly slow drip, and advice about how it can take 12 hours to brew a batch. If you do it this way, you are just dripping water down the centre of the bed of coffee and getting an incredibly uneven extraction. You're also wasting a huge amount of time, because you can easily get a proper extraction with a 60-90 minute brew time.


Our method is 210 grams of coffee, 2,700 grams of ice water resulting in about 2/3 of a gallon liquid coffee in roughly 8 or 9 hours. Out of all the brew methods we tried so far, this one tastes the best and results in a TDS of about 1.53 - it's higher and slightly more concentrated since ice will be added to the cup later.

The coffee and roast level has a significant impact on overall flavor of course, but we tried different ratios, grind, water temp, drip rates, saturation methods, etc and the above formula has worked best for most coffees. I guess the only way you could be convinced is if you tried a cup. Most people who try it really like it, including Dan.

User avatar
Bob_McBob
Posts: 1863
Joined: Wed Jan 21, 2009 7:12 pm
Real Name: Chris Birkett
Equipment: Yes
Location: Waterloo, ON, Canada

Postby Bob_McBob » Thu Aug 15, 2013 2:59 pm

I can't really argue with personal taste preferences, but the method you're describing certainly isn't promoting an even extraction. The math gives an extraction level around 17.5% (WLR is usually pretty low with slow drip), but I would guess it's probably actually a few points higher since you are severely underextracting the portion of the coffee bed the water flow misses. It's hard to imagine how an extremely uneven extraction would improve the taste vs. an even extraction of a comparable overall level.

I don't doubt it takes a fair bit longer than 60-90 minutes to drip 2700 g of water. Pacificmanitou was asking about a small batch of concentrate, which is what I typically brew. I'm also sure your method works a fair bit better than the videos I was describing of glacially slow drips into a slightly damp bed of grounds.
Chris

Nuprin
Posts: 167
Joined: Thu Oct 15, 2009 1:19 pm
Real Name: Mike
Equipment: Linea 3 Group, Quamar M80, Mazzer Robur, Compak K10WBC, Baratza Vario & Virtuoso
Location: Raleigh, NC

Postby Nuprin » Thu Aug 15, 2013 3:49 pm

We have one the small 8 cup Yama brewers as well and we simply use the same brewing parameters. 80 grams of coffee to 1028 grams of water, 12.85 to 1 ratio just like the 25 cup ones. Results are very similar regardless of the size.

Pure even extraction by having the water above the coffee line SOUNDS like it produces the ideal cup but we've found by not doing that, we get better results in the cup. The hot pour-overs are a perfect example. You'd think Press and Clever would produce the best cups but they usually don't. For about 70% of the coffees we try, the Cone Drip, whether the Hario, Bonmac or Beehouse, produces the best results. What methods do you think usually wins Brewer's cup? It's not the Press or Clever.

I've posted about my experience on a west coast trip where all the cafes I visited in SF and LA and their finer grind and stir method yielded over extracted, syrupy coffees that have no balance and complexity. They all tasted homogenous even though I'm sure the coffees are excellent. A medium to coarse medium (for medium and light medium) with a below the top surface pour with no stirring produces a better cup IMO. I tested this with several customers and most seemed to agree as well.

My point is that one should try all various brew methods and see what tastes best before passing judgement. If you haven't tried all the methods and compared them, then you can't say one way is better than another.