Yet another chemistry question - Mark/Stuart, help please !

Seriously, though, here is some interesting information from Harold McGee on making vanilla extract:

"Vanilla extracts are made by chopping whole vanilla beans and repeatedly passing a mixture of alcohol and water over them for several days, then aging the extract to develop a more complex, full flavor. Vanillin and the other flavor components are more soluble in alcohol than water, so the higher the flavor content desired in the extract, the higher the proportion of alcohol necessary to carry it." (432)

From Harold McGee, On Food and Cooking, The Science and Lore of the Kitchen; Scribner, New York, NY 2004

It sounds like you need to constantly pass the alcohol/water mixture over the chopped beans rather than letting it sit idle. Then strain the beans from the solution and let it sit idle and age.

I hope that this helps, Celia.

rwj

I've made vanilla extract before, and I do chop the vanilla beans first. I use vodka and mainly still aging too, Celia, and it's always come out just fine.

It sounds like you need to constantly pass the alcohol/water mixture over the chopped beans rather than letting it sit idle. Then strain the beans from the solution and let it sit idle and age.

It's unlikely to make a difference if you continually pass the mixture over the beans vs. letting them sit. Given the time involved, mixing processes are rapid so you'll end up with the same thing. It might be advisable to swirl the mixture every day or so, to promote efficient mixing, but anything more would be overkill. Note that this would not be true if you were doing a continuous extraction, in which the solvent were passed over the beans never to the reused (which would require much more solvent) as we do with drip filtration in coffee making. There's also the variant known as soxhlet extraction, in which a solvent is continuously boiled and passed over the solid to maximize extraction. This is the method used in coffee percolators, with the known attendant problems.

Mark Lipton

I use 100 proof vodka (50% ethanol solution) to preserve fresh ginger and galangal. The fresh rhizomes tend to shrivel up otherwise, but preserved in vodka they will stay fresh for months. Over time, the vodka turns into ginger or galangal extract.

-Paul W.

I use 100 proof vodka (50% ethanol solution) to preserve fresh ginger and galangal. The fresh rhizomes tend to shrivel up otherwise, but preserved in vodka they will stay fresh for months. Over time, the vodka turns into ginger or galangal extract.

-Paul W.

What do you do with the ginger extract, Paul? Seems like it might be useful in cocktails or is the flavor not really good for that?

young lady?

Young?

rwj

"I grow old...I grow old...I shall wear the bottoms of my trousers rolled.."

T S Eliot The Love Song of J. Alfred Prufrock

Seriously, though, here is some interesting information from Harold McGee on making vanilla extract:

"Vanilla extracts are made by chopping whole vanilla beans and repeatedly passing a mixture of alcohol and water over them for several days, then aging the extract to develop a more complex, full flavor. Vanillin and the other flavor components are more soluble in alcohol than water, so the higher the flavor content desired in the extract, the higher the proportion of alcohol necessary to carry it." (432)

From Harold McGee, On Food and Cooking, The Science and Lore of the Kitchen; Scribner, New York, NY 2004

It sounds like you need to constantly pass the alcohol/water mixture over the chopped beans rather than letting it sit idle. Then strain the beans from the solution and let it sit idle and age.

I hope that this helps, Celia.

rwj

Yep, I knew this, Cowboy, thanks. But it's a difficult process for home use. I have split the beans, and all the seeds are spilling out when I shake it.

Cynthia, I'll take some pics today if I get a chance !

Mark, I'm always throwing chemistry questions at you - thanks for you patience ! Yet another question - does heating the vodka as per Larry's comment make a difference to the end result ? I have read some suggestions that cold macerating produces a better result, and I wondered if it's like olive oil, where cold pressing gives better results...

Howie, Paul, thanks - I'd love some other ideas of what other extracts I can make. I was in the kitchen store recently, and the flavoured extracts were so expensive, it would be nice to be able to make my own (plus just better, in principle). Paul, do you use the ginger and galangal for cooking, or just to produce an extract ? If you're using it in Chinese cooking, can you taste the alcohol in the finished stir fry ?

Cheers, Celia

It sounds like you need to constantly pass the alcohol/water mixture over the chopped beans rather than letting it sit idle. Then strain the beans from the solution and let it sit idle and age.

It's unlikely to make a difference if you continually pass the mixture over the beans vs. letting them sit. Given the time involved, mixing processes are rapid so you'll end up with the same thing. It might be advisable to swirl the mixture every day or so, to promote efficient mixing, but anything more would be overkill. Note that this would not be true if you were doing a continuous extraction, in which the solvent were passed over the beans never to the reused (which would require much more solvent) as we do with drip filtration in coffee making. There's also the variant known as soxhlet extraction, in which a solvent is continuously boiled and passed over the solid to maximize extraction. This is the method used in coffee percolators, with the known attendant problems.

Mark Lipton

I've never actually made the stuff so I am just passing on information. I find this thread highly informative, though.

rwj

My vanilla pictures as promised :

vanilla.jpg

vanilla day 9.jpg

First one was taken on the first day (start day being day 0), and the second one was taken today (day 9).

What do you do with the ginger extract, Paul? Seems like it might be useful in cocktails or is the flavor not really good for that?

It's useful in cocktails, for sure. In a pinch, I've also added a tablespoonful or two to dishes calling for fresh ginger, when I opened the fridge only to find that I'd used all the fresh ginger, and all that was left was the vodka it had been immersed in. Not the same as the real thing, but far better than dried ginger as a substitute.

-Paul W.

[
Mark, I'm always throwing chemistry questions at you - thanks for you patience ! Yet another question - does heating the vodka as per Larry's comment make a difference to the end result ? I have read some suggestions that cold macerating produces a better result, and I wondered if it's like olive oil, where cold pressing gives better results...

Interesting question, ce (and you're much better off asking me chemistry questions than philosophy questions). In principle, using hot solvents just speeds up the extraction process, provided that the solvent is allowed to cool. In practice, it isn't that simple. For a start, hot vodka might alter the vanilla pod itself, dissolving structural materials and making it more permeable. Additionally, the use of the word "successive" in Larry's procedure makes me wonder if they were doing a form of continuous extraction where the pods are immersed in hot vodka for a short period, then moved to a new batch of hot vodka. In such a case, you'll probably extract more out of the pod. Whether that's a good thing or not is debatable, though, overextraction being as big a problem in food as it is in wine The suggestion that cold maceration is better suggests just such an interpretation.

Good luck!
Mark Lipton

Mark, I have worked with people who think it is a good idea to make coffee using distilled water.

You have exactly that problem, over-extraction. Distilled water is "free" in laboratories though and probably to them it just sounds like a good idea, the coffee is somehow "cleaner."

But to my palate it is like drinking coffee with a teaspoon of baked beans stirred in. There is a sweet beany flavor that I just detest. I'm fussy about my coffee and my salvation was the little 3 cup coffee maker that I got when I started subscribing to Gevalia. Not that Gevalia is the best stuff around, it is just that having that coffee maker is a godsend at my office. I actually carry in water from home. We "process" tap water, letting it stand 24 hours so the chlorine blows off, and then putting it through one of those filters in a pitcher. Tastes darn good after that and is probably the exact equivalent of a lot of pricey bottled waters.

F

Mark, I have worked with people who think it is a good idea to make coffee using distilled water.

You have exactly that problem, over-extraction. Distilled water is "free" in laboratories though and probably to them it just sounds like a good idea, the coffee is somehow "cleaner."

But to my palate it is like drinking coffee with a teaspoon of baked beans stirred in. There is a sweet beany flavor that I just detest. I'm fussy about my coffee and my salvation was the little 3 cup coffee maker that I got when I started subscribing to Gevalia. Not that Gevalia is the best stuff around, it is just that having that coffee maker is a godsend at my office. I actually carry in water from home. We "process" tap water, letting it stand 24 hours so the chlorine blows off, and then putting it through one of those filters in a pitcher. Tastes darn good after that and is probably the exact equivalent of a lot of pricey bottled waters.

Frank,
I too am a bit of a fussy coffee maker/drinker. I drink only one cup a day in the morning, as per my prenup, and so I want it to be the best I can make it. At home, I also use tap water that's been filtered and cooled; at work, I use cold water drawn from a water cooler that Jean and I share in an outer office (it uses spring water, not distilled water). Cold water is important, as the dissolved oxygen (which increases at lower temperature) is critical for the "nose" of the brewed coffee (complex oxidative reaction taking place to liberate thiols, of all things). I'd guess that distilled water would not be good, as those trace minerals in drinking water contribute to the flavor of water -- and probably also to that of coffee. As for your assertion that the filtered tap water is equivalent to the bottled stuff, I'd disagree. It's almost certainly far better (fewer organics). But how do you connect distilled water to overextraction? I don't follow.

Mark Lipton

[
Mark, I'm always throwing chemistry questions at you - thanks for you patience ! Yet another question - does heating the vodka as per Larry's comment make a difference to the end result ? I have read some suggestions that cold macerating produces a better result, and I wondered if it's like olive oil, where cold pressing gives better results...

Interesting question, ce (and you're much better off asking me chemistry questions than philosophy questions). In principle, using hot solvents just speeds up the extraction process, provided that the solvent is allowed to cool. In practice, it isn't that simple. For a start, hot vodka might alter the vanilla pod itself, dissolving structural materials and making it more permeable. Additionally, the use of the word "successive" in Larry's procedure makes me wonder if they were doing a form of continuous extraction where the pods are immersed in hot vodka for a short period, then moved to a new batch of hot vodka. In such a case, you'll probably extract more out of the pod. Whether that's a good thing or not is debatable, though, overextraction being as big a problem in food as it is in wine The suggestion that cold maceration is better suggests just such an interpretation.

Good luck!
Mark Lipton

This is SO interesting. I should have paid more attention in Chemistry class at high school. If you think about it, you'd be effectively cooking the vanilla, which will obviously produce a very different end product. I'm reminded of the confit process, where you cook meats by leaving them in barely warm oil for a long time.

Thanks, Mark !

Celia

Hi Mark

Let's see -- I came away from all that P Chem and "molality" and stuff not remembering the equations but with sort of a set of pictures in my head, and I hadn't doubted that they were right, but who knows. I see distilled water as kind of an empty sponge, and tap water (especially "hard" water) as having some of its potential to dissolve things already used up. Thus the hard water won't take the soap off your skin when you shower. It's already got such a high ionic content that there isn't "room" to suck up the micelles of soap and body oils.

I know that what I said about the taste of coffee made with DW is true, that flavor has been the same when I've tasted DW coffee off and on over the past 30 years. So, where does that baked bean flavor/smell come from? My thought was exactly what you were saying about the vanilla beans. If you have more dissolving power, you can get not just the flavors you want, but also other flavors and smells that you don't want. Instead of pure vanilla or pure coffee scents, you start picking up some of that vegetable undertone.

How does all that hit you?

Frank

Hi Mark

Let's see -- I came away from all that P Chem and "molality" and stuff not remembering the equations but with sort of a set of pictures in my head, and I hadn't doubted that they were right, but who knows. I see distilled water as kind of an empty sponge, and tap water (especially "hard" water) as having some of its potential to dissolve things already used up. Thus the hard water won't take the soap off your skin when you shower. It's already got such a high ionic content that there isn't "room" to suck up the micelles of soap and body oils.

OK, I see where you're going. Dissolved solutes can affect the solubility of other things, but it can go either direction. Those dissolved minerals increase the polarity of the water, which I'd expect would lower the solubility of greasy things like lipids. The parallel you draw to hard water is a bit leaky, though. Hard water is hard not because of ionic strength per se, but rather because many calcium salts aren't terribly soluble in water. That's why water "softeners" just use ion exchange resins to replace the calcium and magnesium with sodium, thereby solubilizing detergents (and that's why, in our area with ridiculously hard water, softened water feels slippery to the touch -- all that dissolved Na2CO3 puts it at pH 10 or so).

I know that what I said about the taste of coffee made with DW is true, that flavor has been the same when I've tasted DW coffee off and on over the past 30 years. So, where does that baked bean flavor/smell come from? My thought was exactly what you were saying about the vanilla beans. If you have more dissolving power, you can get not just the flavors you want, but also other flavors and smells that you don't want. Instead of pure vanilla or pure coffee scents, you start picking up some of that vegetable undertone.

How does all that hit you?

Hard to say, I guess. I'd have to smell that "baked bean" thing with you and try to diagnose what is and thereby infer where it's coming from. How about this, Frank? Has all that distilled water come from the same source? Is it possible that it's actually contaminated (from an unclean still) with a volatile component that smells to you like baked beans? Or, how about this? Distilled water has a lower boiling point than ordinary tap water (those dissolved minerals raise the boiling point of water), and when water boils it is completely degassed. As previously mentioned, dissolved oxygen is essential for good flavor, so perhaps the distilled water is being degassed because, at the heat used to make coffee, it boils where regular tap water doesn't (that's why instructions for brewing coffee call for using water that is just off-boil).

Just a guess,
Mark Lipton

I was under the impression that part of the reason for distilled water tasting "flat" was the lower amount of dissolved oxygen. True?

You realise, of course, that this is all just too cool for words.

Cheers, Celia the Chemistry Groupie

No, different buildings, different departments, different stills.

And if DW has a smell it's pretty f'ing bad DW, right? We actually have distilled and deionized water in some of the labs.

I personally think if you try making a pot of coffee with DW you will see exactly what I am talking about.

An easy experiment...

F

I was under the impression that part of the reason for distilled water tasting "flat" was the lower amount of dissolved oxygen. True?

Distillation will completely deoxygenate the water (true at any phase boundary) and the oxygen will only slowly redissolve, so -- yes -- that's likely true. I've also heard, though, that simply deionizing the water is enough to ruin its flavor, so take that for what it's worth.

Mark Lipton

No, different buildings, different departments, different stills.

And if DW has a smell it's pretty f'ing bad DW, right? We actually have distilled and deionized water in some of the labs.

Hmmm.... There's another possibility: could it be the lack of electrolyte ions? A simple way to test that would be to make some coffee with deionized (but not distilled) water and see how it tastes.

EDIT: When in doubt, Google it! It seems that the coffee geek community is in consensus that distilled water makes lousy coffee, and their explanation is the lack of minerals in the water. See the following links:

http://www.sweetmarias.com/grind.brew.html
http://www.barnonecoffee.com/coffee_faq.html

I personally think if you try making a pot of coffee with DW you will see exactly what I am talking about.

An easy experiment...

Well, I'll tell you one thing: I ain't takin' water from our DI faucets in lab to make my coffee! No way do I trust that stuff enough to do that. Besides which, our "DI" water is actually purified by RO, so isn't really distilled. However, I'll get a bottle of Dasani water from a vending machine and make my coffee from it tomorrow. That's distilled water.

Mark Lipton

You realise, of course, that this is all just too cool for words.

Cheers, Celia the Chemistry Groupie

You're probably the only person apart from a few seriously sick indivduals who would say so, ce.

Mark Lipton

I know at least one physics groupie.

It might be fun to try bubbling air through some DW, then making coffee with it, to test the minerals-are-good hypothesis.

Here is the follow-up!

I started the vanilla extract on 6th April, so it's been nearly four months (can you believe it?). Last week I decanted off the extract into clean bottles, and reused all the pods to start a fresh batch (adding new ones as well). There is a marked difference between the batch I did with straight vodka (blue lid) and the batch which had added filtered water (pink lid). The straight vodka batch went much browner, and smells more intensely of vanilla. Both are very usable, but for future bottles, I'll be using straight vodka. The other thing I found out was that extracting a large number of pods in a big bottle of vodka works better than putting one pod in a small bottle, even if the proportions are the same. Not sure why...

vanilla 030808.jpg

Oh, and we seem to get a more intense vanilla flavour from using the extract than we do from using scraped beans! Go figure. I think perhaps the best way to get maximum value from vanilla pods is to use them to make extract, and then to use the extract as your vanilla flavouring. Using the vanilla extract, we were able to make the most delicious vanilla syrup for milkshakes and coffee....mmmm...