Nerd Nite Presentation- Death by Chocolate: The Pleasures of Materials Science

11 May

I’m giving a Nerd Nite talk tonight.

Here’s a link to my slides.

Please feel free to leave any feedback in a comment.  I’d love to continually improve my chocolate lectures.  Be as mean as you like…..



Death by Chocolate: The Pleasures of Materials Science
Nerd #1: Colin Gore

Nerd Nite ColineditMaterials scientists use their understanding of physical laws to tailor the properties of industrially important materials like steel, concrete, and…. chocolate! You’d probably never expect it, but the cocoa butter in chocolate forms tiny crystals that determine the look, feel, and taste of a candy bar. Colin will lead you on a journey toward understanding the pleasurable properties of chocolate using both quantitative and qualitative methods, with occasional detours about history, clean energy, and other cocoa-y errata. And yes, “qualitative” does mean “tasting”…courtesy of a local chocolate retailer.

Bio: Colin is a doctoral candidate in materials science at the University of Maryland, College Park. Through his research, he’s trying to save the world by developing conductive ceramics for renewable energy technologies. In order to be reminded of why the world is worth saving in the first place, he spends a lot of time tinkering, cooking, and sharing meals. In fact, he has probably made lab or kitchen equipment from something stolen from your garbage bin. Colin also currently holds a world record in human-powered flight duration, which he has been told rounds out his Daedalus-like inventor qualities (for the record, cocoa butter would make an even worse feather adhesive than wax).


Absinthe Fountain on the Cheap

8 Sep

From Multipurpose Components that are Handy to Have Anyway

As promised, I will kick off the new round of posts with some low-cost mimicry of high tech (or just plain expensive) items.  There are myriad expensive gadgets to covet in the “modernist” kitchen, but many of us do not have the expendable bankroll to acquire many of them.  In the end, flavor enhancement is a result of the technique, not the gadget, so I have gone on a personal mission to deconstruct several modernist cooking gadgets and get similar results from cheaper, more available parts and a dram of elbow grease.   I first posted about a vacuum packer for <$100 fit for sous vide bag prep, vacuum infusion, or compression techniques.  Admittedly, I relied on a few lucky finds to build it so cheaply.   Next up is something a little more simple from more readily available materials.

My collection of made-in-the-USA absinthes inspired the following DIY project…

As an absinthe enthusiast who may “know a guy” who has a house recipe, I have coveted Belle Epoque style absinthe fountains for a few years now.  The fountain adds both a nice aesthetic, ritual appeal as well as enhancing the flavor of the absinthe by allowing smaller oil droplets to precipitate, which gives a creamier mouthfeel (for you thermodynamics nerds, the precipitation is a result of spinodal decomposition!).  A slow drip rate is vital to getting good, creamy mouthfeel since the properties of the microemulsion formed are determined by kinetics and alcohol concentration, as confirmed by our boys Hervé This and Erik van der Linden.   The really sexy fountains have a sticker price of $300+, however, so I could never justify pulling the trigger on such a single-purpose item.

On the left is my favorite fountain. Classic, classy, clean. Calamitously costly at ~$400.  To the right, a popular but kitschy model that does similar amount of damage to your pocketbook.

Here is a video from Alandia, a prominent absinthe shop, demonstrating the use of the fountain.

I originally posted in the Wormwood Society forums about a homebrewed fountain idea that I pulled off for ~$40 using items that I can use for other purposes as well.  The aesthetic is more Bell Jar than Belle Epoque, but so it goes.  Perhaps that is more fitting for my guests anyway.  The gory details are provided at the following link.  I’ll post separately about making the ring stands out of oak.

My new $40 absinthe fountain

The apparatus is complete!

Returing to Earth

6 Aug

Gore sinks back to Le Monde

I am assuredly not the first person to neglect a blog.  It’s been over a year and a half since I have publicly posted anything here.  I have 37 posts in draft mode awaiting further polishing, but clearly none of them have been a huge priority since many just need less than an hour to be of publishable quality.  There were a few other big projects that came to fill my free time, but they are drawing to a close.  They are not explicitly cooking related, but encompass curiosity and scientific inquiry so I am going to give a quick overview that should be roughly contiguous with the theme of this blog.

The first is greenhouse related.  A series of fortuitous coincidences has prompted me to lead two passive solar greenhouse projects for over the past few years.  One at Lehigh University and a NSF-funded greenhouse at a school in Maryland, all in the name of interactive, tangible solar education.  But it all started because I wanted to grow a few collard greens on my back porch.  The article in Growing Magazine covers the Lehigh project quite well.

The second project, which is kind of way cooler, pertains to human-powered flight.  My power-to-weight ratio happened to fit the needs of a team of engineers in University of Maryland’s Aerospace department.  I joined team Gamera as a pilot in December of 2010, not knowing what to expect from such a kooky sounding project.  Now we’ve set a few world records and are still going.  I can leave knowing I’m the 4th person to ever achieve human-powered vertical lift, and currently have made it higher than any other attempt at a whopping 4 feet off the ground.  The Atlantic wrote us up, so bonus points for that.

Also, somehow, I am hopefully getting a PhD in materials science amidst all of this.  I promise to post more before that happens.


We flew again recently, and I set a new world record for duration, making me the first human to break the 60 second barrier for vertical flight.  More excitingly, I got to 8.6 feet in the air!  Then crashed….

My World Record Flight for Duration (Currently being verified by FAI)

My Height Record and Crash!!!

A Gleaner’s Vacuum Packer

26 Jan

A Chamber Sealer/Packer for Under $100

I’ll fill this out with more photos as I take them.  This will ideally become more of a how-to guide, but an open ended one since you can’t really plan for gleaned goods.  You can be prepared to find certain types of objects, and that’s why the guide is necessarily verbose.  For now, look at the writeup I’ve posted here:

Pun intended, and facilitated by the failure of the adhesive on a particular bike helmet sticker.

JoresTech 12" Sealer

Guts of the sealer reveal the section that's convenient to hack off so it will fit into the chamber.

Chamber with sealer installed.

Text from CI forum post:
“I know it’s been a while since this thread has been active, but I thought I’d offer some tips based on my experiences with a seriously bootleg vac chamber I’ve been using and tweaking for the past year or so. I’ve been meaning to write about it for almost as long, but I have made tweaks frequently enough that it never quite felt finished. I believe Galen in particular, with his conceptual homebrew contraption that rather resembles mine, will appreciate the dumpster-diven finesse of the rig. The chamber is 12″ in diameter with a 16” tall Pyrex bell jar, pulls at least 5-10 mmHg (maxes out an analog gauge dial, boils icy water) in 2 mins, will hold that vacuum level overnight when the pump is off, and now has an impulse sealer for vacuum bagging. All for under $100, though like I said, fueled primarily by luck and a passive approach to searching for parts. So keep in mind, this is a guide more than a set of instructions since not all steps are strictly repeatable.

I get my pumps by gutting AC’s that people leave on the curb. Well, actually, my first came from the AC my roommate dropped out of his second story window. My neighbor works with HVAC systems, so I have him drain the refrigerant, and then I cut the compressor out. Before cutting anything take pictures of how it is all wired, and find and remove the starting capacitor. It’ll be a silver cylinder about the size of small tomato paste can with a few sets of prongs on top. The capacitor usually has two sets of tabs, one for the fan and one for the compressor. I anticipate that getting these backwards would cause problems, but I don’t know for sure. If you have any questions about how to wire one up, or any other questions about the whole schebang, leave a message on my blog and I’ll give you a hand.

Don’t hacksaw the copper tubes, though, as the filings can damage the pump if they get sucked in. Use a proper tubing cutter for a clean cut and clean edges. This will also make it easier when you want to attach gas-tight fittings to the copper inlet tube. So far, all of the AC compressors I’ve harvested are made by Rechi. If you get one of those, you can look up the model’s specs here:

Assuming a Rechi compressor, you’ll see a 1/4″ tube and a 3/8″ tube coming out of it. The 3/8″ is the inlet, which will pull the vacuum, and the 1/4″ is the outlet. Some cotton balls or polyfill stuffed into a small plastic bottle (I used airplane whiskey bottles, because that’s what I had) will make a decent filter when slid over the outlet side. For the inlet side, I use swaged tube fittings like Swagelok, A-lok, Let-Lok, Nupro, or whatever is cheap on eBay (mix and match, they’re all pretty much compatible), to connect the pump to my chamber with copper or steel tubing. I have two valves on my rig. One binary ball valve, and one 3-way ball valve. I use the 2-way on a tee-union to vent the pump to atmosphere before shutting it off. The 3-way is after the 2-way and is used to isolate the chamber and vent the chamber without sucking from the tubing that may have oil contamination. I’m sure this is annoying to visualize, I’ll post pics on my blog since I don’t have any other image host. For now, this will have to do:

Chamber ====(3-way)=====(2 way)===== Pump===Filter

My first chamber was a quart-sized mason jar. It was good for deairing alginate baths or other gels and for vacuum infusing anything that met my whimsy. They’re cheap, ubiquitous, and can withstand the vacuum. I epoxied the vacuum tube into the interchangable jar lid, so I could swap chambers (jars) as necessary. That’s handy when you’re working with hydrocolloids that you want to degas. For reverse spherification, for instance, blend alginate in one jar and your filling in the other, degas both, then work straight from the jars. No sloppy transfer necessary. Top the jars if you want to store them in the fridge for later use. These little chambers are handy and cheap when paired with a good AC pump, but the jars are small. You need something way bigger to house a sealer or to evacuate lidded mason jars for storage of products under vacuum.

While I was toying with the idea of shelling out for a large diameter PVC tube and lexan (because who isn’t going to use alcohol in their chamber? Seriously…) I happened upon something better. A friend was getting rid of a large bell jar from a defunct vacuum chamber and asked me if I could help take it to a recycling center. Instead, I got to take it home. Since it’s a dome of Pyrex, it didn’t require a clear base, so I used a piece of epoxy lab table rescued from a dumpster with a hole drilled for the vacuum tube. Sealing was my main problem then. I was looking for a large piece of silicone to seal, but couldn’t find anything big enough (~13″ diameter to outer edges of glass) at the hardware store, nor did I want to shell out much loot to buy some online in case it didn’t work for me. Instead, I tried plumber’s putty, and that’s what I’ve stuck with for the past ~6 months. I stays pliable, so just make a ring on the table, plop your chamber on it, and pump it down.

The next “chamber” was an inexpensive vacuum distillation setup, but that’s another story. More on that later.

Turning the vacuum chamber into a chamber packer was the next step. The cheapo impulse sealers ($20-50 range) appear to all be identical, despite being sold under different names. Mine’s labelled JoresTech, I think the guts of it say something else though. I got an 8″ sealer figuring it would fit in my 12″ diameter chamber. No dice, it was 12.5″ wide with all the handles and support mumbo jumbo. Luckily, if you dismantle it and remove/relocate the control circuit, you can hacksaw 2.5″ off the one side while leaving the rest of the sealer intact. The lever has a silicone strip that is spring-loaded that you push into the bag/heating wire. In order to activate the sealer, you have to put a fair amount of pressure on the springs. This does seem to create some backpressure in the bag (it inflates a lot), and it’s hard to get a full evacuation of the bag with too much pressure on the lever. It’s hard to get a good seal with too little. You can hit the sweet spot, but it takes some tuning and a sometimes a few tries. Another problem is that when liquids boil, they condense a bit on the bag which can cause sealing troubles. I think I’ll try fishing some thin filament through the base so I can pull the lever down after the final vacuum is achieved. That should at least alleviate the backpressure issue.

Oh, and to deliver power to the sealer, I drilled a hole in the base of the chamber that matched the diameter of an extension cord, fed the cord through, sealed it with some putty, and wired it into an outlet inside the chamber. The sealer plugs into that outlet.”

Brown Butter “Espresso”

5 Jan

Brilliant or terrible idea?

As I mentioned in the previous post:  Financiers turned me on to almond flour.  They also turned me on to brown butter or beurre noisette.  In fact, Michael Laiskonis,  the pastry chef at Le Bernardin whose recipe I used when making financiers, attests that this cookie is his favorite showcase for what brown butter can be.

This stuff has quite a passionate following, pretty much every food writer I esteem has written about brown butter at least once, and rightfully so.  After tasting it, I have difficulty conceiving of how so much richness can be packed into this stuff.  The scent alone evokes indulgent, desirous flutterings that tingle in parts of my brain that I’m not regularly aware of.  As for the flavor, it is surprisingly nutty for something that was merely a stick of butter just moments before.  In fact, the French call it beurre noisette, with noisette meaning “hazelnut.”  A linguistic testament to the divine nutty essence exuded by this ingredient of humble origins.  Simply simmering butter in a saucepan and whisking while it foams, the foam breaks, and crispy brown solids form in the bottom of the pan will give you the gold.  It’s like making ghee or clarified butter, but take it darker than regular.

The solids are usually an ephemeral little bit of deliciousness.  I never measured the amount of solids I got when making financiers, but I’d say there was maybe 1 tablespoon tops for the whole pound of butter (32 Tbs).  That’s a bit better than 3% yield, so I never had much of a plan for the miniscule amount of solids.  But boy were they good!  Nutty, roasty…how can you go wrong with milk sugar and protein that are caramelized and toasted in butterfat?  Later I saw that Laiskonis had mentioned a trick for getting more solids.  Start with cream instead of butter.  This made sense, since cream has more solids than the butter we typically buy.  I heard a few years ago that most stick butter is a byproduct centrifuged from whey leftover from cheesemaking.  The solids are used in the cheese, so the butter has less of them.  I imagine that traditional butter, being churned directly from cream, would be a different story.

Simmering heavy cream into brown butter solids: 1) cream reduces 2) cream begins to brown 3) solids begin to separate from oils 4) mixture froths and solids continue to brown. This is about where you want to stop

I tried starting with cream, and it turned out splendidly.  About 25-30% of the cream, by weight, becomes toasty solids, a full order of magnitude better than starting with butter.   Other folks have since made large amounts of solids by adding dried milk powder to the butter.  I have yet to try this and compare.  For now I can say that if you’re after clarified butter oil, then start with sticks.  If you want brown solids, go with the cream.

With a large amount of brown butter solids in my fridge, and having pondered pressure extractions starting a few months ago, there was only one rational conclusion.  I need to try making an espresso from brown butter solids.

My solids were quite thoroughly crisped.  They’re a very dark brown verging on black, and as I said they have a roasty, intensely nutty, slightly bitter flavor.  The texture is not far off from finely ground coffee, albeit very oily coffee.  I strained most of the oil from them, but enough remained that they cling together into almost a paste.  I imagined that the resulting infusion would either be fantastic, like everything else with brown butter is, or exceptional in being the first disgusting thing made from the stuff.

I dosed some butter solids into the portafilter, loaded it, pressurized, and voila… brown butter espresso.  It helped to let the solids, which came straight from the fridge, heat up in the filter for a while as the machine heated up.  I tried to pull a shot before it had all melted, and that caused the filter to clog momentarily.  It flowed smoothly once the remaining butter clinging to the solids liquefied.

And it was actually good.  It begins with the aroma, a firm, but not overly pungent, essence of brown butter.  The flavor has the intriguing characteristics of the brown butter solids, but in a mellower, better melded form.  Additionally, there’s a lingering bright note like you might find in a lightly roasted coffee.  That takes a few seconds to register, while the roasty, nutty notes are right up front.  The body of the shot is also very pleasant.  Smooth, velvety, savory, a bit rich, but not rich in the way cream is, more like the way a full-bodied stock can seem to coat your mouth in a very satisfying way.  It even gets a little mock-crema on top, which is a nice touch.

So in short, this style of extraction gives delectable brown butter flavor without the oiliness of the butter, or the grit of the solids.

Next on deck are hot brown buttered rums and beurre noisette + coffee espresso.

Cookies and Milk

4 Jan

Hot from your espresso machine

During a lunch break few months ago (this all went down in November, but I am just typing it up now) I managed to fix the leaky espresso machine that a labmate had brought in.  Afterward, I started thinking more about coffee and espresso.  This naturally lead to thinking about pressure extraction of other items as well.  The first things that came to mind were other typical beverages; cocoa seemed like it might be interesting, tea seemed like it would be lousy and bitter (and after googling around, it seems that decent tea from an espresso machine seems to be a holy grail of sorts; it usually sucks.  There’s one commercial tea called “red espresso” that’s rooibis based, so that doesn’t even really count.), some herbal infusions might be interesting.  Then I tried to focus a bit.

Coffee beans get some of their flavors from oils and some from other dissolved solids.  I was curious about other ground things that had similar properties.  Cocoa powder again came up, but it’s too fine.  It would just turn to sludge and compact without letting much of any liquid through.  I needed something with larger particles that would give some structure to the stuff as the water is forced through it, like coffee does.

Having also been interested in almond cookies like financiers at the time, I had a sack of almond flour around.  I realized it might fit the bill, since it is oily but also has water soluble flavors, and it also seemed like it might not pack so densely when pressurized that the water would have trouble passing through.  Also, most importantly, it seemed like it could be good.  I’m fond of almond milk, especially when it isn’t garishly sweetened, and this method seemed promising for extracting the good stuff.

Later at the office I fired up the espresso machine, double checked that none of my labmates had nut allergies, lightly packed the portafilter basket with almond flour, and pulled a shot.  The first few drops of creamy, pale almond milk dripped out, then the flow stopped though the pump was still churning.  The filter clogged.  It turns out that the almonds get too soft when the hot water is pumped through them, so the channels for the water to pass through were quickly sealed up.  The drips of almond milk that did pass through were something fantastic, though.  It was the creamiest, most richly flavored almond milk I’ve ever had.  Bad yield, but good stuff.  Also, the flour in the portafilter was now a compact, moist puck of almond paste.  I tired that too, and it was not bad.  If the moist Manischewitz macaroons that come in a can can be called a cookie, then I feel justified in calling my puck a cookie.

So we have cookies and milk.  I like it.

Later I pondered tweaks to the almond that would prevent clogging.  Either I had to keep the almond from compacting somehow, or I had to add something to keep channels open despite the almond compacting.  I opted for the second route, since I was using pre-ground almond flour (Bob’s Red Mill) and couldn’t control the coarseness of the almond, etc.  Long firm bits of something would help create channels for the water to pass through while still capturing flavor.  I wanted the addition to contribute flavor as well as being functional.  Fresh shredded coconut came to mind.  Both coconut milk and coconut oil have full, nuanced flavor, and the shape of the shredded pieces seemed about the right size for creating channels in the almond.

I picked up some coconut and gave it a go.  I added maybe a half teaspoon of coconut to the basket along with the almond flour, making sure they were mixed together well.  While pulling the shot, the milk streamed much more smoothly.  It had a layer of creamy foam on top, which swirled as the cup filled and added a nice visual touch.

Eventually the filter did clog, but I was nearly done pulling the shot anyway.  This milk wasn’t as creamy as the few dribbles of pure almond, but I suspect that’s simply because more water passed through this one.  The coconut flavor melded nicely with the almond, and there was a slight hint of rosewater.  the body was great: full, in no way watery like most commercial almond milk, but not oily or overly rich. The almond-coconut cookie I knocked out of the filter was much more flavorful than the pure almond, as well as having a firmer texture.  It was a bit like a moist macaroon.  I suppose both coconut and almond can be used in a macaroon, so it makes some sense.

The milk and cookie pairing was gone nearly as quickly as it arrived.  I didn’t even have time to dunk.  There’s a lot of room for growth here, mainly in the cookie’s texture.  The flavor is great, but I’m not accustomed to enjoying this level of moistness in a cookie.

Things to try in the future:

-coarser almond flour for better channeling.  Since mine is pre-ground, I’ll have to grind my own if I want coarser, and that’s a whole new bag of worms.  Toasted almond flour might hold up better, so maybe I’ll try that first.

-focus on improving the cookie’s texture without diminishing the quality of the milk. Maybe finish the cookies in the oven to firm them up and enhance the flavor.  Unfortunately this will let the milk get cold, but I usually take my hot cookies with cold milk anyway.  There is still something to the near-instantaneous materialization of cookie and milk when the milk is pulled and the cookie puck is popped onto the table.  I don’t want to lose that.  Maybe finish the cookie with a flame?

-a small amount of bitter almonds added to enrich the flavor (the heat will boil off the hydrocyanic acid that makes them poisonous)

-espresso machine financiers: add a bit of powdered sugar and some brown butter solids

Oyster Mushroom Oysters

30 Oct

Further proof that all good ideas begin with a pun.

For my first mushroom cookoff with the Mycological Association of Washington, I managed to set the bar pretty high with a wicked Chicken of the Woods find. It’s the massive orange thing below.  I prepared it quite simply, sautéing it with a bit of lemon zest, garlic, white wine, butter, and asparagus, but it was fresh and delicious.  Plus there was a bit of an awe factor what with the fifty-pound fungi find that fueled the food.

Laetiporus sulphureus: The Chicken of the Woods


So I felt that I had a lot to live up to for my second cookoff.  Unfortunately, during my foray into Greenbelt Park the weekend before the event, I found not a single edible fungi.  All I found were ticks and an itinerant “drink chef” named Robert Smith who walked here from Chicago.  I obviously had to have the latter over for a dram of HG La Fée Verte (very local absinthe, if you catch my drift).  The former came home without an invite.

Robert Smith. Not a mixologist. A drink chef.


Settling for storebought ‘shroms, however, just didn’t sit well with me.  They can still be tasty, but they’re nothing special in themselves.  Other myco-folks would be sharing their hard-earned hauls, so I had to do something interesting for it to feel like a fair exchange.

I don’t even recall exactly how I was struck with the idea, but I know it was a Sunday, I was in a solarium, and I had spherification on the brain.  The idea was half-baked, of course, and it went something like this:

There are oyster mushrooms.  Why not mushroom oysters?  That would be clever.  Oyster mushroom oysters?….This is a great idea.

Fresh in my memory were translucent sacs created when spherifying liquids in an alginate bath.  I had recently (~4 days prior) been bit by the hydrocolloid bug.  My reverse alginate spheres had always looked a bit oblong and mucousy translucent.  So do oysters.  A darling coincidence, to be sure.

So I made a simple oyster mushroom soup with a bit of  extra calcium added, then dropped sponfulls into a bath of sodium alginate.  Voila… oyster mushroom oysters.  The spitting image of the real deal.  Well they were a bit off.  Needed something.  Ah, minced scallions!  Good for the soup anyway, and they add some color to the monotone guts of the soup oyster.  Served with proper oyster fixings, they should be slurped like a raw oyster.  The warm, savory soup bursts on your tongue. Delicious.

This hooliganery landed me second place in the cookoff out of a good 50 people.  I ran out of tasting samples before the queue forming at my table had subsided, so I fantasize that I could have nabbed first if I merely had a bit more to share.