Monday, July 27, 2009

DIY: A fruit picker made from recycled materials

Two years ago, I wrote a somewhat light-hearted piece about the "depluminator," a device that enabled me to pick plums from limbs high on the two plum trees in my yard. It was really simple, consisting of a rake, a box, and a bungee cord.  But it didn't work very well.

I soon learned that there were much better fruit-picking tools available at the hardware store. These tools typically consist of a basket made from coated metal that has an open top. Several 'fingers' reach into the inside of the basket to allow you to grab onto the fruit and pull it into the basket (Forage Oakland has a photo of a picker).  So this year I went shopping for one, but blanched at the $25 cost.  I also decided that I didn't want yet another highly specialized piece of equipment that would sit around doing nothing 51 weeks each year.

A DIY Fruit Picker
So I brainstormed on how I could build my own picker and had an inspiration: a one-gallon plastic bottle could be the body, bent wire hangers could form a frame and the 'fingers' that grab the fruit (Joan Crawford*, as portrayed in Mommie Dearest, would not approve), and some thin wire could hold everything together. In the end, I needed just a few items:
  • 1 one-gallon water bottle, preferably with a screw-top lid
  • 2 washers with a diameter slightly smaller than the interior of the cap
  • 1 wood screw
  • 4 wire hangers
  • 1 broom stick (or dowel or other rod-type item)
  • 1 foot of thin wire (twist-ties might work too)
And just a few tools:
  • A drill
  • A wire cutter that can cut through hanger wire
  • Pliers to bend the hanger wire
  • A screwdriver
The next photo is the finished device.  At the bottom is a broomstick. Above that is the bottle, which is attached by driving a screw through the cap. The bottle itself has a frame of hanger wire (3 pieces) and the fingers on the top right (more photos are below).

First, I needed the right bottle. I found a clear one-gallon bottle from Crystal Geyser that had the perfect shape and was also transparent, something that would be helpful during harvest. It was filled with 2-year old tap water, part of my neglected earthquake supply kit, so I could repurpose it easily.

Next, I used some heavy-duty wire cutters to remove the hooks from the hangers (and cut them into smaller pieces as needed). With a pair of pliers, I bent three pieces of wire around the bottle to act as structural support and a place for the 'fingers.'  To hold the two ends together, I bent the each end into a loop, and then hooked them together, as the photo below shows.

After making the frame, I needed to make some fingers.My first attempt with the fingers was a poor one that resulted in too much finger rotation as I tried to hook onto the plums in the tree. A day later I had a better idea:  use a single piece of hanger wire to form all of the fingers, thus removing the possibility of ringer rotation.

The fingers were formed by bending the wire into a series of U-shapes, with a much tighter bend radius at the top, somewhat like one-half of a potato masher. Then I bent the fingers 90 degrees so they would reach into the bottle after being attached to the frame.

The next step was to carefully remove the bottom of the bottle (which will become the top of the picker), taking off more material on the side opposite the eventual location of the fingers to provide more grasping area for the fingers.

I used thin wire to connect the fingers to the frame in several places, as the photos below indicate. I used this wire because I happened to have it in my tool box, but I imagine that twist ties could also be used to secure the frame and fingers together.

The last step was to attach the bottle cap to a broomstick.  I drilled a hole in the center of the cap and a pilot hole in the broomstick (to prevent the wood from splitting as the screw went in).  Then, with a washer on each side of the cap for strength, I drove a screw into the end of the broomstick so that the threads of the cap were facing out.  The bottle can easily be affixed to the cap for fruit picking and then removed for storage.

The Performance
The picker was a decent success, enabling me to pick a few more pounds of plums for the annual plum jam extravaganza.  This year, like last year, I made some of the jam using sugar as the sweetener, and some with honey to make an all-local jam.

* Speaking of Joan Crawford, I've never seen the Mommie Dearest biopic, but think she was remarkable in the noir classic Mildred Pierce.

Cross posted at La Vida Locavore

Random link from the archive: Save the Basil! A Tip to Keep it Fresh

Tuesday, July 21, 2009

A hearty discovery: Finnish Rye Bread in Maggie Glezer's "Artisan Baking"

One of my favorite breads to bake is a sourdough walnut loaf from Maggie Glezer's "Artisan Baking." The crumb has great flavor, the walnuts add wonderful richness and a hint of bitterness, and the crust is sometimes amazing. In the middle of a recent week, seeing that I'd have time for baking on the upcoming weekend, I started feeding my sourdough starter twice a day to bring it up to proper strength. Alas, at too late of an hour to get more (or, more precisely, after I had decided I was done shopping for the weekend), I discovered that my walnut inventory was too low to make the walnut loaf.

And so I needed a different recipe. I looked in the index of "Artisan Baking" for other sourdough recipes.  It had to be sourdough, after all of the work feeding the starter, commercial yeast wouldn't do.  As I browsed the index, "Finnish rye" jumped out at me. I had never made it and it looked interesting:  a good dose of whole grains (rye flour, whole wheat flour, and cracked rye grain), some molasses, and some flax seed for extra nutritional zip.  Even though it was mid-July, a time in much of the United States when hearty breads don't fit the climate, Berkeley's fog allows mid-summer heartiness.

Like all of the other breads I have tried from this outstanding book, the Finnish Rye was a winner, even though my loaf spread out too much because of a slight under-addition of flour. The flavor was deep and dark, the texture interesting because of the whole grains.  It was delicious toasted with a slather of mustard, a slice of cheddar, a slice of tomato, and a tangle of homemade sauerkraut.

Glezer's book has taught me a lot and helped me bake some amazing loaves (one of them has been a tasty part of my lunch this week, a rosemary-laced focaccia-like loaf). Although some breads, like the ciabatta seem like they are far too wet during the fermentation and proofing processes to ever become a loaf of bread, they always seem to work out. I also appreciate how all of the ingredients in all of the recipes are listed in grams, ounces and volume. It is so much easier to put a mixing bowl on the scale and add ingredients until the weight has changed by the right amount. This is especially great to sticky ingredients like molasses, honey and malt syrup, which can make a huge mess of a measuring cup. If you are looking to increase your bread baking skills, or just looking for some variety, give this book a try. 

Random link from the archive: Pie blogging - Meyer lemon meringue and Mission Pie
Technorati tags: Bread : Baking : vegetarian : Food

Saturday, July 18, 2009

Why are drinks in Singapore called "CoolBlog" and "SoyaBlog"?

Walking to the bus stop after dinner on my last night in Singapore in May, we passed two drink shops near City Hall with amusing names —  "CoolBlog" and "SoyaBlog"  — and a great slogan —  "Be cool with a refreshing blog." Each stand appears to make the standard collection of juice and soy drinks — blended fruit, bobo tea, chilled soy milk, and the like. As far as we could tell, there was no reference to the internet. And there is no record of the shop on the internet (according to Google and Google blog search, anyway).

After I left, my contact in Singapore went back to take these photos and asked the person behind that counter about the name.  She had no idea where it came from.


So I'm still wondering:  why "blog"? I can't think of many drink names that could be abbreviated or acronym-ized into something resembling blog. "Blended Liquid is Outrageously Good" is the best I can do at the moment. What could be the inspiration for the CoolBlog and SoyaBlog names?

Random link from the archive: Introducing the depluminator
Technorati tags: Singapore : Food

Wednesday, July 15, 2009

Afternoon Tea in the Laboratory: a Scientific Paper about Brewing Tea

Painting of tea leaves and blossoms from Flore Médicale, by F.P. Chaumeton et al., 1820
(Updated 10/23/16:  new image, fixed broken links)

Sometimes, when afternoon fatigue weighs me down at the office or on groggy weekend mornings, my mind drifts to thoughts of tea and caffeine. How could I brew the most potent cup of tea to break out of the doldrums? What are the flavor trade-offs? Among the many choices involved in a cup of tea — brewing time, water temperature, type of tea, quantity of tea, size of tea leaves, to name a few — which are most important?

So I dove into the U.C. Berkeley library and found a few very interesting articles that helped answer my questions. Over a series of posts, I'll be reviewing some of the papers that I found. The first one is the least theoretical, containing not a single equation. Written by five researchers from Unilever (owner of Lipton), Factors Affecting the Caffeine and Polyphenol Contents of Black and Green Tea Infusions was published in 2001 in the Journal of Agricultural and Food Chemistry.

All tea comes from the Camellia sinensis plant. There are two main variants, C. sinensis var. sinensis (also known as the China type) and C. sinensis var. assamica (also known as the Assam type). China tea is primarily grown in China, Taiwan, Japan, and parts of Darjeeling (India). Assam is grown pretty much everywhere else. In general, the Assam type contains more caffeine, with the difference depending on the source of the tea (how it was grown, where it was grown, etc.).

Afternoon Tea in the Laboratory

The authors brewed numerous cups of tea (or, more likely, flasks of tea), using a variety of brewing durations, tea leaf sizes, tea bag sizes, and a few other changes, then performed chemical analysis of the resulting brew.  Brewing the tea for 30 seconds extracted about 33% of the total caffeine from the tea leaves, a 60 second brew extracted 50%, a 120 second brew extracted 73%, and a 300 second brew extracted about 91%. So doubling the brewing time from 30 to 60 seconds increased the caffeine content by almost 50%, but increasing the time by two-and-one-half times from 2 minutes to 5 minutes only increased the caffeine level by 25%. In other words, in the early moments of brewing, caffeine easily pours out of the tea leaves, but the rate slows significantly over time. (Another post about the caffeine content of tea looks at this subject in more detail.)

They next looked at how teabag design, leaf size, and agitation influence the quantity of soluble solids transferred to the water, but did not report caffeine measurements.  I read the paper carefully without finding any indication of whether results obtained for soluble solids would be applicable to caffeine.  Nonetheless, some of the results are interesting. Continuously dunking a teabag in hot water — as opposed to dropping it in and letting it sit — dramatically increased the soluble solids:  by 500% for small leaves and by 213% for large leaves for a 4 minute brew.  Whereas an agitated teabag filled with small leaves created a stronger cup of tea than one filled with large leaves (40% more soluble solids), the opposite effect was observed for an unagitated bag:  large leaves made the tea stronger than small leaves (67% more soluble solids). Considering the size of the tea bag, a large bag mades a slightly stronger cup of tea (only 17% more solids).

To get the strongest brew — or, at least, the highest level of soluble solids — use loose leaves. For a four minute brew, loose leaves gave solids levels that were 25% to 50% higher than those from the most potent teabag. For example, a 4 minute brew provided a solids concentration of 5800 mg/L for loose small leaves versus only 4500 mg/L for dynamic brewing with a small-leaf-filled teabag.  Although they didn't mention it in the article, I'm assuming that they didn't constrain their loose tea leaves in a metal cage or ball, which is probably not much better than a teabag in terms of letting water come in contact with the leaves.

Contact is Critical

For all of the results in the previous paragraph, it comes down to getting the water in contact with the leaves so that soluble compounds can diffuse into the water. Dunking the bag essentially forces water through the leaves while also moving the leaves around inside the bag, providing new areas for contact. A teabag limpidly soaking in the water is at the mercy of much weaker forces to bring the water and tea into contact. The paper has a technical description of the process that I won't subject you to here.

Black Teas are Fairly Consistent

At the conclusion of the article, the authors present data for eight black teas and fifteen green teas, all in teabags, brewed according to the instructions on the package. Of course, not all tea bags had the same shape or quantity of tea inside, so instead of being a valid brand-to-brand comparison, the results give a rough survey of what you'd find on the shelf at the market.

The figure below shows the caffeine results for the black tea varieties (arranged in no particular order).  The dashed vertical line is the mean of the results. Although most of the teas lie close to the mean, one variety had a much higher caffeine level (PG Tips), and one a much lower level (Co-op 99). I suspect, however, that the tea for each of the manufacturers changes during the year, perhaps because of slightly different sourcing or other factors, so the bars might move around.

Chart of caffeine content of black tea brewed from teabags

Wide Variation in Caffeine from Green Teas

The figure below shows the results for the green teas (because I don't want to type in the green tea brands, I've labeled them as A through O.)  The range is quite amazing, from 40 mg/L to 200 mg/L, with a few a good distance from the mean (indicated by a vertical dashed line). If we were to assume that the tested green teabags are a representative sample of the population, and that one were to follow the instructions on the box, it would mean that there is a 20% chance that the caffeine level will be 40% or more above the mean, and a 20% chance that the caffeine level is 50% below the mean. At the higher end, there is even some overlap with the black teas.

Chart of caffeine content of green teas
For brands C, D, and E, a double-brew method was recommended on the package. This method has the following steps:  pour hot water over the teabag, let it brew for one minute, discard the one-minute tea, add new water, brew again for three minutes, and then remove the teabag. This practice is used primarily for green teas, where it is believed to improve the flavor and also reduce the caffeine level.  Unfortunately, this article can't confirm whether the brewing method has any effect on the caffeine because the authors didn't perform an experiment where they didn't discard the first minute. Based on what I have seen in other articles (one of which will be the focus of the next post on tea), discarding the first minute would reduce the caffeine content by about 50%.

Conclusions about Caffeine in Tea

To sum up some of the findings in the article by the Unilever researchers, to get the most from your tea, use a loose leaf variety. If you must use a tea bag, agitate it in the water to allow the most contact between water and the leaves. Caffeine levels that can be obtained from different brands of teabags can vary significantly.

The full citation for the article: "Factors Affecting the Caffeine and Polyphenol Contents of Black and Green Tea Infusions," by Conrad Astill, Mark R. Birch, Clive Dacombe, Philip G. Humphrey, and Philip T. Martin, Journal of Agricultural and Food Chemistry, 2001, 49 (11), 5340-5347, DOI: 10.1021/jf010759+

Image Credit
Painting of tea leaves and blossoms from Flore Médicale, by F.P. Chaumeton, Chamberet et Poiret, illustrated by E.M., illustrated by E. Panckoucke and P.J.F. Turpin, published by C.L.F. Panckoucke (Paris), 1820 (full text on Google Books, original from Lyon Public Library)

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Saturday, July 11, 2009

Minor fail: mechanized coconut grating

One of the comments on my post about coconut grating pointed to a Thai company that specializes in coconut grating equipment.  One of their products is a hand-held tool that looks a lot like a drill, with the bit replaced by a nasty-looking grater (like the one in the above photo of my hand-cranked grater ).

Inspired by this product, I removed the grater from my hand-cranked grater (pictured above) and installed it into my electric drill. It was a mixed bag:

  • The good:  No personal injury.*  I wore gloves and was very careful when the sharp tool was spinning.   
  • The bad:  The grating tool is so long that it flexes and is hard to control. Also, it was not easy to hold onto the drill and coconut at the same time. 
  • The ugly:  On the rare occasions that I got the grater going, I was unable to control it and it usually ended up digging into the coconut shell, bringing flecks of brown shell into the bright white grated coconut flesh.
I gave up after a few minutes and went back to old-fashioned hand cranking.

The difficulty in holding the coconut and drill at the same time is why a connection to the KitchenAid would be useful — the tool would be still and I could move the coconut around to extract all of the coconut from its shell.

* - No injury while using the drill, anyway.  Later in the cooking session I cut my finger on the grating tool when removing it from the grater after the coconut was fully grated.  I should probably wear gloves whenever I handle the grating tool.

Random link from the archive: Torta verde: a savory pie from Italy

Technorati tags: vegetarian : Food

Monday, July 06, 2009

A new candidate for the misleading label Hall of Fame

While shopping for such goodies as corn tea at the Koreana Plaza in Oakland recently, I bought a bottle of aloe juice out of curiosity. I had tried it before and liked it, and I was probably feeling some subliminal effects of the magical aloe product that is advertised on the fringes of digital TV (11-3, the NBC sports channel, for example).

Reading the label — "No Added Sugar" — and then the ingredients — "...corn syrup, honey..." — I realized that I had run across a new nominee for the Misleading Labels Hall of Fame.  Sure, there is no added sugar, but corn syrup and honey are nearly the same as sugar and provide nearly half the calories in the drink (100 calories overall in 250 ml).

The designers of this aloe juice label clearly missed the memo that sugar is cool again:  Hansen's, for example, has been labeling their drinks as "Cane Soda" for over a year (as I wrote about at The Ethicurean, while also presenting some charts of historical sugar and HFCS consumption in the U.S.).

Cross posted at La Vida Locavore.

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Technorati tags: Korea : Food