Comments on: Wonders of extraction: Water

By: blog.khymos.org » Blog Archive » Wonders of extraction: Espresso (part I)

Mon, 10 Nov 2008 23:14:13 +0000

[…] posts in the extraction series: water, ethanol and […]

By: blog.khymos.org » Blog Archive » Wonders of extraction: Oil

blog.khymos.org » Blog Archive » Wonders of extraction: Oil — Fri, 24 Oct 2008 22:49:10 +0000

[…] a polar and a non-polar end falls in between oil and water. I’ve covered extractions using water and ethanol previously. That water and oil are opposites is easily observed by the fact that they […]

By: restaurant a paris

restaurant a paris — Fri, 24 Oct 2008 02:13:16 +0000

thanks for the info::))

By: Papin

Papin — Mon, 09 Jun 2008 01:53:20 +0000

I sometimes enjoy making tea by letting the leaves infuse at room temperature. The leaves sit in the water for around ten hours and I find the tea less bitter. In the case of tea, the infusion process seems to be very dependent on the geometry of the leaves: variations of around 20% in size cause fourfold variations in the rates of extraction. (Mike Spiro has published a lot on infusion, see http://dx.doi.org/10.1002/jsfa.2740321115 for example.)

By: Colin

Colin — Sun, 08 Jun 2008 17:06:44 +0000

Thanks for the info. I also ground the beans another time and the infusion was more pronounced.

By: Paul.

Paul. — Sat, 07 Jun 2008 22:43:24 +0000

@Colin–the different compounds in cofee (and there are many) dissolve at different temperatures. Fortunately, many flavorful compounds readily dissolve at low temperatures albeit slowly. The compounds that we tend to perceive as bitter in coffee tend to dissolve more readily (i.e., faster) at higher temperatures. I’m sure the fat in the cream dulls the perception of whatever of those bitter compounds have dissolved in your decoction.

If you wanted to change the rate of dissolution without changing the temperature you might want to experiment with changing the unprotected surface area of your coffee (i.e., grinding the beans). It’s hard to give you precise guidelines because the variables would include the type, freshness and roast of the beans in question as well as the size of the grind.

Hope this helps.

By: lizet

lizet — Thu, 05 Jun 2008 10:36:15 +0000

Coincedence: yesterday, in the archives of a 18th century castle I dug up a recipe ‘a method of making rose oil in Asia’ dating from 1829.
“Manière de faire l’eau de Rose en Azie. On effeuille les roses dans un vase de bois dans lequel on met de l’eau bien pure; et on les expose pendant quelques jours au soleil; la partie huileuse se separe et surnage l’eau, on ramasse doucement cette huile précieuze avec du coton fin, on l’exprime dans de petites bouteilles qu’ on bouche hermétiquement. Voila tout le sécret de cette essence, qui se vent si cher a Constantinople, et en France quand on peut en avoir.”
So, it seems that roseleaves steeped in water in a wooden bowl, put in the hot Asian sun will loosen the fragrant oil, which then can be gathered.
Of course, not for consumption but as a perfume. As in the Netherlands we seldom have temperatures of this kind, woud the oven be a good substitute?

By: achemist

achemist — Wed, 04 Jun 2008 23:29:42 +0000

Actually, saying “one end has a small negative charge and the other a small positive charge” for water is not exactly correct. The net dipole is negative on one end and positive on the other. H2O is shaped kind of like a boomerang with the positive charges on the ends and the negative part at the center of the curve.

“Polar molecules are more easily extracted than non-polar molecules.” Yes, for water. Obviously that changes when you move to more non-polar substances, like ethanol and of course oils or fats.

With tea, a bit part of the flavour profile is not just the extraction/temperature per se but also the oxidation by oxygen dissolved in the water and by other compounds in there as well. This becomes obvious if you try to ‘reuse’ and reheat previously heated water. I think this is also why traditional Asian tea recipes call for boiling the water and then cooling it slightly before use - it not only lowers the temperature appropriately but gives it a chance to reoxygenate.

By: Colin

Colin — Wed, 04 Jun 2008 17:45:46 +0000

For latte panna cotta I steeped whole coffee beans in heavy cream overnight in the cooler. Made for a very smooth and un bitter coffee flavor. I know you are talking about water but I’m sure fat plays a critical role in many extraction. Also, Does this mean you could make herb consomes in the same manner? I wonder what the time would be? and what is the right temp? Thanks for the new experiment

By: Martin Lersch

Martin Lersch — Tue, 03 Jun 2008 21:06:07 +0000

It is true that baking soda will change the pH, but blanching doesn’t really have anything to do with extraction.

I can be reached at webmaster (at) khymos dot org.

By: Weston

Weston — Tue, 03 Jun 2008 20:25:08 +0000

How Do I Email you anyways
Found this link on the study of pH levels of blanching done by a canning company
http://www.aseanfood.info/Articles/11016477.pdf

By: Weston

Weston — Tue, 03 Jun 2008 20:16:19 +0000

I know one place were I use to work we used baking soda in the water instead of salt for blanching, that would change the pH wouldn’t it?