Ancamo Senior Member Joined: 23 Jun 2006 Posts: 156 Location: Gatineau,Qc Canada Expertise: I love coffee
Espresso: Gaggia Classic Grinder: Baratza Vario Vac Pot: Yama 5 cups Drip: Aeoropress / CCD Roaster: POPPERY I / SC-TO
Posted Mon Aug 6, 2012, 7:54am Subject: Enjoying new Bonavita but questions regarding brew ratios
Hi all I just received my Bonavita brewer for our busy mornings, instead of brewing double americanos in the am and drink bad coffee at work, I dediced for now to go with a drip brewer so my wife and I can enjoy a cup at home and fill a travel mug to drink later at work, saves time for both of us while busy with the kids, and we don't have to put up with crap coffee at the office.
So far I've brewed with the 60g/1L ratio, which makes a very good, strong tasting coffee. Not bad strong but good strong, but still too strong for my wife's taste, for now I just dilute her coffee with some hot water and milk to weaken it a bit but I was wondering what happens when you play with the parameters like for example, while keeping other variables the same:
What makes it stronger, weaker, more bitter, gives you more delicate flavors (aeropress style)? I grind with the Vario (set for espresso with Macro at the top micro in the middle) for the Bonavita with the Macro in the middle, and use #4 bleached (rinsed) mellita filters.
Posted Mon Aug 6, 2012, 10:39am Subject: Re: Enjoying new Bonavita but questions regarding brew ratios
Pascal, on one hand, the questions about more/less water or coffee are really altering one parameter: brew ratio (whether you consider it as grams of coffee per gram of water, or the inverse).
60g/1L is approximately a brew ratio of 16.7g water per gram of coffee. We'll refer to the WATER brew ratio rather than the coffee brew ratio.
Raising this ratio will produce weaker coffee, lowering this ratio will produce stronger coffee. This would be a general rule regardless of whether you changed the coffee to alter this ratio, or changed the amount of brew water to alter this ratio.
However, since the Bonavita is an auto drip brewer with a delivery rate around 3.2g/second, changing the amount of brew water will change the overall delivery time. 1.25liters will take about 6.5 minutes, where 1liter will be more around 5:15 or so.
So, in general, if you change the brew ratio by changing the coffee amount and using the same brew water, the general thoughts on brew ratio apply (more water = weaker, most other things constant), but changing the brew ratio by altering the amount of brew water will change the overall delivery time - and will tend to partially compensate for the stronger brew ratio by extracting less (less time).
Coarser grind will increase the percolation rate, resulting in lower strength for a given brew ratio. Coarser grind will also tend to promote channeling, which will reduce dissolution (i.e. lower extraction), and lower strength. Finer grind will reduce the percolation rate, increasing contact time and pooling, and will PROBABLY increase strength and have a tendency toward overextraction.
More Water (Same coffee): [increased water brew ratio] increased delivery time, overall strength may be weaker or same, will probably contain elements of overextraction.
Less Water (same coffee): [reduced water brew ratio] reduced delivery time, overall strength may be stronger or same, will probably be normally extracted and taste fine.
More Coffee (same water): [reduced water brew ratio] stronger coffee, extraction MOSTLY unaffected unless the brew ratio is well below 11.
Less Coffee (same water): [increased water brew ratio] weaker coffee, flavor should be pretty good as determined by the other parameters.
Finer Grind: [decreased percolation rate] higher strength coffee, possibly overextraction flavor if extreme. Also run the risk of clogged filter, overrunning the basket, etc.
Just my observations, your observations may vary. Hope that helps. You could probably plot these on a brewing control chart.
(correction made to one of the parameters - sorry!)
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Mon Aug 6, 2012, 12:01pm Subject: Re: Enjoying new Bonavita but questions regarding brew ratios
One other note:
at 16.7g water per g of coffee (60g coffee/liter), your strength at proper or slightly high extraction will be on the stronger side of the "Lockhart Sweet Spot" (18%-22% extraction and 1.15%-1.35% strength, based on a typical absorption of 2.0)
W=1000 (Brew Water) (assume the liter is ambient temperature, or close enough to 1.0 density) C = 60 (Brew Coffee) A = 2 (Absorption) E = 20% (Extraction)
R = 16.67 (Water Brew Ratio, 1000/60)
Cp ~ 880g (Coffee Produced)
S ~ 1.36% (Strength, or TDS%)
Just for kicks, try simply using 52.5g of coffee (water brew ratio of 19) - don't change anything else - and see how your wife likes the strength. This change should adjust the strength only, but not the flavor profile:
W = 1000 C = 52.5 A = 2 E = 20%
R = 19
Cp = 895
S = 1.17%
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Ancamo Senior Member Joined: 23 Jun 2006 Posts: 156 Location: Gatineau,Qc Canada Expertise: I love coffee
Espresso: Gaggia Classic Grinder: Baratza Vario Vac Pot: Yama 5 cups Drip: Aeoropress / CCD Roaster: POPPERY I / SC-TO
Posted Mon Aug 6, 2012, 12:09pm Subject: Re: Enjoying new Bonavita but questions regarding brew ratios
Wow this is a very informative answer, I will try what you are suggesting for tomorrow and see how it goes, in the mean time I will digest all that information and make sure I put it to good use in the future!!
Posted Mon Aug 6, 2012, 12:26pm Subject: Re: Enjoying new Bonavita but questions regarding brew ratios
Ancamo Said:
Wow this is a very informative answer, I will try what you are suggesting for tomorrow and see how it goes, in the mean time I will digest all that information and make sure I put it to good use in the future!!
No problem, sorry if it's too much - I tend to overcompensate because I've had so many "experts" purposefully obfuscate coffee knowledge. Some of this stuff is mysterious, but not the majority of it. LOL
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Mon Aug 6, 2012, 2:33pm Subject: Re: Enjoying new Bonavita but questions regarding brew ratios
Pascal,
Here's a graphic that sort of illustrates what I was saying.
There's three lines showing brew ratio of 16, 16.75 and 17.75 (orange, green, light blue respectively) - the more water, the less strong.
Strength is on the vertical axis (in decimal form, 0.0125 is 1.25%). "Extraction" is on the horizontal axis with an assumption of 2 for absorption. Should be pretty close for the Bonavita.
The big black oval is the Lockhart "sweet spot" for brewing, where extraction is between 18% and 22%, and strength is between 1.15% to 1.35% (usually shown as a square, but I think of it as more fuzzy like an ellipse).
The little dot is where you are if you are extracting at 20% (you say you like the taste, it is just strong, so I assume you are neither over nor under extracting). The arrows show approximately what happens if you change the three parameters (water amount, coffee amount, grind coarseness).
Changing the water amount changes two parameters - the brew ratio and ALSO the overall contact time (by altering the total delivery time - your brewer total cycle time is based on a fixed amount of heat and delivers a set amount of water per unit time. More water takes longer to deliver, but more water with the same coffee means a weaker brew ratio.).
You can also alter the temperature of the brew water in the reservoir - using hotter water will have a small increase in delivery water temperature, but also will shorten the delivery time. It's also a pain in the butt (preheating water just to put it into your automatic brewer!).
Hope it helps.
(Click for larger image)
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Ancamo Senior Member Joined: 23 Jun 2006 Posts: 156 Location: Gatineau,Qc Canada Expertise: I love coffee
Espresso: Gaggia Classic Grinder: Baratza Vario Vac Pot: Yama 5 cups Drip: Aeoropress / CCD Roaster: POPPERY I / SC-TO
Posted Tue Aug 7, 2012, 10:38am Subject: Re: Enjoying new Bonavita but questions regarding brew ratios
I tried with 52.5g this morning and got interesting results, not as strong but still pretty strong, which makes me start to think that it may be over-extraction that I'm getting……
So next step will be to make the grind a bit coarser and see how that tastes!
Thanks a lot for the graphs and all it really helps understand everything and I'm sure it will help a lot of people who stumble upon this post
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