Hi All,

Many of you helped in my brewing method. I am brewing using a Bonavita and grinding with a Breville smart grinder. Beans (ethopian) are fresh from red bird.

I grind about 24g of beans, average grind size for drip
I use about 15oz of filtered water
I wet the paper cone with hot water
Hit brew

This makes an excellent cup of coffee. However, if I double the water/grinds for two cups (30oz), the cup is no where near as good.

What's the problem?

Sounds like quite the mystery. While I cannot explain the non-linearity of your process, I would suggest up-dosing, especially for the bigger brew. 30 ounces of water is roughly 900 ml, and I would try 63 grams of coffee for that amount. I always dose Ethiopians at 7 grams per 100 ml water, and have never regretted it.

Best of luck.

Any time you add more dry coffee mass to the same size filter, you also change flow rate and sometimes flow path. I think most brewers have an ideal batch size, but generally, if you increase the batch size, grind coarser. If decreasing, grind finer.

Bbdude wrote:Hi All,

I grind about 24g of beans, average grind size for drip
I use about 15oz of filtered water...

However, if I double the water/grinds for two cups (30oz), the cup is no where near as good.

What's the problem?

Who knows.

Do offer, as another has suggested, that you upsize the coffee. I use 60 grams for 30 finished oz of coffee. I am on the heavy side. I believe SCAA suggests .06 times water weight to determine grams of coffee. Mine is about .065.

Thanks, gents. I'll try it out and post back.

Just out of curiosity, can you describe what was not good about your 6 cup brew?

Too weak? too bitter?

Bbdude wrote:Hi All,

Many of you helped in my brewing method. I am brewing using a Bonavita and grinding with a Breville smart grinder. Beans (ethopian) are fresh from red bird.

I grind about 24g of beans, average grind size for drip
I use about 15oz of filtered water
I wet the paper cone with hot water
Hit brew

This makes an excellent cup of coffee. However, if I double the water/grinds for two cups (30oz), the cup is no where near as good.

What's the problem?

Bbdude wrote:...This makes an excellent cup of coffee. However, if I double the water/grinds for two cups (30oz), the cup is no where near as good.

What's the problem?

Presumably the water dispense time is twice as long? (as the flow rate is proportional to the heating power and the starting water temperature).

All other things being equal you would expect the extraction yield to be significantly increased if you doubled the water dispense time.

You could try to compensate for this by grinding coarser for the larger brew.

There may be other effects like the relative ability of the Bonavita to effectively wet and provide turbulence to beds of different depths.

6 cups was stronger, perhaps a little bitter. The roasty/nutty notes in the coffee over power the blueberry notes in the 6-cup as compared to the 3-cup where the blueberry notes are perfect.

Yes, because it takes twice as long to brew the 6 cup.

Good day,

I was re-reading this thread as I progress through the learning curve of home brewing. I have a Chemex Ottomatic and have also been venturing into traditional pour over as well.

Based upon what I have been reading, brew time seems to be the best constant to shoot for during most kinds of brewing. It seems many people recommend a 4 min brew to cup for pour over method for one or two cups. This brew time is recommended since it must offer the best extraction time for the volume desired. Correct?

So for an auto brewer for a small volume (2 or 3 cups) one can adjust the grind so you get a 4 min brew time. And then for larger amounts (4 cups or more) you can adjust the grind again, to accommodate a 4 min brew time?

It would seem logical that this would give you a similar cup..or am I too simplistic in my assessment?

Any thoughts?

Thanks.