Pour out first drips of coffee brew?

#1: Post by **faustroll** » March 15th, 2014, 1:18 am

In this video by Cafe Demitasse (below), the guy brewing a Kalita Wave says you should pour out the first drips from the bloom/prewet because they don't taste good. I've never heard of this before. Does anyone have any more info about how common this technique is or the extraction science behind it?

Also of note is they are doing a brew ratio of 14:1 .

March 15th, 2014, 1:34 am

Actually now that I've thought about it, the explanation doesn't make sense to me.

He's talking about carbonic acid which I thought was very volatile and not really soluble in hot water. Isn't that what those little bubbles are in the bloom? Carbonic acid off-gassing as CO2 into the air, not the cup?

Not going to discount there could be other reasons for doing what they're doing, just that their explanation of it doesn't convince me.

#3: Post by **another_jim** » March 15th, 2014, 3:43 pm

faustroll wrote:In this video by Cafe Demitasse (below), the guy brewing a Kalita Wave says you should pour out the first drips from the bloom/prewet because they don't taste good. I've never heard of this before.

It used to be standard technique in 1950s and 1960s espresso with highly fermented naturals or super rubbery robustas. I've tried it with very ferocious tasting good coffees for espresso; but there are better techniques for taming these (lower dose, finer grind). As far as I know, it was never used for pour overs.

I'm guessing they are improvising with a coffee that is creating difficulties for them. The current fashion of underroasted coffees, often tainted by very cutting and bitter tasting chlorogenic acids, may be the cause. These acids extract quickly, just like the fermented and rubbery funk in cheap coffees; so getting rid of the first flush, like when brewing green tea, may work to improve the cup.

#4: Post by **LaDan** » June 9th, 2014, 9:04 pm

faustroll wrote: Also of note is they are doing a brew ratio of 14:1 .

Consider that he is throwing away the first ~15% of the coffee (eyeballing it), and then he goes by weight (to the total weight of water added after pouring the first 15%), then the brew ratio is more like 1:16.

And if you consider that the first 15% is more concentrated than what comes after, then the brew ratio is even higher than 1:16.

#5: Post by **Boldjava** » June 9th, 2014, 10:41 pm

Makes no sense to me at all.

#6: Post by **oktyone** » June 9th, 2014, 10:44 pm

It's always an interesting idea to "deconstruct" a pourover or espresso brew by changing the receiving caraffe/cup at 25% 50% and 75% of the total brew time and taste what kinds of flavors are extracted at each "stage", and then combine them altogether and see how they balance each other out..

#7: Post by **LaDan** » June 9th, 2014, 10:51 pm

Good luck pulling that paper filter out every 25% pour. LOL!

June 11th, 2014, 4:54 am

I believe the idea is that you would lift the wave/v60/etc and switch to a new cup. Although you may need an extra hand to avoid spillage....

#9: Post by **Jaxx2112** » June 11th, 2014, 4:57 am

faustroll wrote:In this video by Cafe Demitasse (below)

Anyone else notice him totally crushing his filters shape with the prewet? Could've sworn the SOP for Kalita was to pour heavy down to the middle to keep the ridges intact... Heck, most Cafe's i've been to with Kalita just prewarm the brewer & serving carafe and then plop a dry filter in the middle. The bleached filters don't *really* need much of a rinse at all.

#10: Post by **oktyone** » June 11th, 2014, 10:46 am

Jaxx2112 wrote:I believe the idea is that you would lift the wave/v60/etc and switch to a new cup. Although you may need an extra hand to avoid spillage....

It's easy enough with a pourover stand that has a drip tray, such as the Hario one, but yeah, having an extra helping hand makes things a lot easier!