Showing posts with label science. Show all posts
Showing posts with label science. Show all posts

5/04/2014

Triple-chocolate crunchy cookies

These were an attempt to replicate a store-bought cookie from my childhood for a local cookie contest.  Although they flopped at the contest, my family loves them.  First I make two very crunchy, chocolate cookies with chocolate chips.  Then I sandwich them around a chocolate ganache filling.  For the grownups, I spice the ganache with cinnamon and cayenne.  I also put a little gelatin in the ganache to firm it up, because there's nothing worse than cookie filling that squoozes out the sides when you bite it.

To get the cookies really crispy-crunchy, I used a lot of tricks from this page:  I used white sugar instead of brown, used high-protein flour, melted the butter, and swapped the whole eggs for whites only.  I also added some extra baking soda (as is sometimes done with crackers).  But I ultimately had to resort to double-baking the cookies, biscotti-style, to get them to stay crisp once filled.

In a medium bowl, sift together:

  1. 5.25 oz (1 c + 2 T) King Arthur all-purpose flour
  2. 1 oz (1/3 c) cocoa powder
  3. 3/4 t baking soda
  4. 1/4 t salt


In a standing mixer, combine with the paddle:
  1. 5.25 oz (3/4 c) granulated sugar
  2. 1 stick (8 T) butter, melted
  3. 1 egg white
  4. 1 t vanilla extract

Mix in the dry ingredients, just until thoroughly combined, followed by
  1. 5.25 oz (1 c) chocolate chips

Chill the dough while the oven preheats to 375 F, about 20-30 minutes.  Line three cookie sheets with parchment.  Portion the dough by generous rounded half tablespoons, to give 36 cookies (12 per sheet).  Smash the balls into disks, so the final cookie sandwiches won't be too thick.  Bake each sheet for 14 minutes, one at a time, and let cookies cool on the sheet.  Turn the oven down to 300 F.  (I leave the oven door cracked for ~10 minutes to speed this up.)  Bake the cookies for another 15 minutes to dry them out and make them really crunchy.  You can also consolidate the cookies down to two sheets at this point, and even bake one on the lower rack and one on the other if you're in a hurry.  When they're done, let them cool completely on the cookie sheets.

In the meantime, in a 2-cup Pyrex measuring cup, combine in this order:
  1. 1/4 t powdered gelatin (such as Knox)
  2. 1/4 t ground cinnamon
  3. 1/8 t ground cayenne pepper
  4. 1.5 oz heavy cream
  5. 6 oz chocolate chips
  6. pinch of salt
Microwave on high ~45 seconds, then whisk until smooth.  Let cool on counter until cookies are ready.  Ganache may look slightly oily / broken;  it will be fine, just stir it back together before spreading.  Spread filling on the bottom of one cookie and top with another, to make 18 sandwiches.  Keeps up to a week in a tightly sealed plastic container.

4/22/2010

Ginger ale -- REAL ginger ale

Ever since I tasted Reeds, I've had a thing for ginger ale.  If all you've ever had is Schweppes or Canada Dry, you're in for a treat.  Real ginger ale is sweet and sour and piquantly spicy all at the same time.  It's anything but the bland, pedestrian soda you sipped as a kid when you were sick (although the ginger in the real stuff may still be good for an upset stomach).


When we lived in Seattle, there was a coffee shop in Freemont that sold homemade ginger ale in unmarked brown glass bottles.  It was good stuff, but I don't know of an equivalent in Durham.  Besides, ever since I got into making wine, I've wanted to try making my own soft drinks.  As it turns out, making soda is far easier than making wine, and you get to enjoy the results a lot faster.

Yes, soda originally involved fermentation with yeast, back in the days before we made machines to force carbon dioxide into liquids under high pressure.  The process is essentially the same as making beer or wine, except the bottle is kept closed to capture the carbon dioxide generated by the yeast, and the fermentation is stopped early, before any significant amount of alcohol is produced.

There are a few tools and ingredients that you need, so I'll get those out of the way first.  Only two or three are truly unusual, so it's really not hard to get started!

  • Wine yeast.  People generally recommend Red Star Premier Cuvee, as it ferments fast and clean.  I also tried Lalvin EC1118, but got less carbonation.  The little packets are about $1 each, so it's dead cheap if you have a homebrew store nearby.  If you do mail order, everybody charges $10 in shipping, although American Brewmaster in Raleigh was slightly cheaper.  It is possible to use regular baking yeast to make soda, but it adds some distinctive flavors that, while not terrible, are sort of distracting.  Having tried both, I'd highly recommend springing for the wine yeast.  Store it sealed in plastic in the freezer for up to a year.  Each packet holds enough to make several gallons.
  • Food-grade citric acid.  Citric acid is what gives lemons and limes their zing, and what makes many soft drinks pleasantly tart.  You could use real lemon or lime juice, but I think you'd need a cup or two to get the same effect -- kind of a pain.  Many other recipes include cream of tartar (a.k.a. tartaric acid) instead, for "mouth feel", but I can't see that it contributes anything useful -- I think citric acid works much better.  You can get an 8 oz bag of citric acid from the New England Cheesemaking Supply Company for $5 and it will last you a lifetime.  Besides, you need to order...
  • High thread count cheese cloth.  The "cheese cloth" you find in the grocery store is too open to actually catch much of anything;  the real stuff has a much tighter weave.  Get the 90 thread count Butter Muslin from New England Cheesemaking at the same time you get the citric acid.  A couple layers of this will catch most of the ginger residue when you strain your soda.
  • Coffee filters (optional).  Straining the ginger ale through coffee filters removes the fine particles that otherwise make the final product hazy instead of clear.  The cheese cloth is still necessary to first remove 99% of the big chunks that would otherwise clog your coffee filters in an instant.
  • Four 1L bottles or two 2L bottles.  Get plastic seltzer bottles (1L) or soda bottles (2L), ones that are designed to hold carbonated liquids under pressure.  I prefer the 1L bottles because there's less soda left over to go flat.  (However, bottles will re-pressurize to some extent as they sit in the fridge.)  If you try to use regular spring water bottles, they'll leak or deform or pop.  Plastic is also safer than glass (e.g. beer bottles), because you can feel how much pressure there is by squeezing, instead of taking you best guess and praying nothing explodes.
  • Two large pots.  Each should hold a gallon of liquid comfortably.
  • A sieve or strainer.  It's much easier if you can suspend this above one of the pots.  The mesh doesn't matter;  you'll line it with coffee filters and/or cheese cloth.
  • A funnel and ladle.  For filling the bottles -- trying to pour from the big pot doesn't work so well  :)
  • A food processor.  A blender might work in a pinch.  If you have a juicer, I hear this is great for ginger, but I haven't tried it personally.
  • An instand-read thermometer.  For measuring the water temperature.  If you don't have one, 100 F feels like warm (but not hot) bathwater.  It's better to be a little under than a little over, because overly hot water will kill the yeast.
  • A digital kitchen scale.  You can get by without it, but it makes all your cooking so much easier.  Spend $25 and pick one up from Amazon.  Get one that does at least 5 lbs. in 1/8 oz increments or finer.  You won't regret it.
Now, on to the recipe!  Because you're trying to grow microorganisms in sugar water on your countertop, cleanliness is worth paying attention to, so that you grow the right microorganisms.  But since it's only out for a few days before it goes in the fridge, you don't have to be crazy about, and you certainly don't have to sterilize everything.  A nice wash with soapy water will be just fine.


(3 oz peeled ginger)


In the food processor, combine
  1. 3 oz peeled ginger root, or to taste
  2. 18 oz granulated sugar (2 1/2 c)
Run the food processor for several minutes, until you have a uniform, light golden paste.  Processing the ginger with the sugar ensures that it gets chopped much finer than it would by itself.  Three ounces of ginger makes a pleasantly zippy ginger ale.  If you like more of a kick, try 6 oz.  I like it that way, though most of my friends don't.  I've tried all the way up to 12 oz, but it just burns your mouth and is no fun to drink.  Also, some recipes recommend using brown sugar, but I find this muddies the taste.

In a large pot over medium heat, bring to 100 F
  1. 4 L water
Use your soda bottles to easily measure out 4 L of water.  Remove from heat, scrape in the ginger paste, then add
  1. 3/4 t citric acid
  2. 1 T vanilla extract (optional)
This is a good time to taste the mix, and adjust anything that wants adjusting.  Don't put your germy spoon back in the pot!  Let it sit for 10 or 15 minutes to make sure all the flavor gets extracted.

Set the collander over the clean pot, and line it with overlapping coffee filters.  Place several layers of fine cheese cloth over the filters.  Strain the mixture into the clean pot.  Sprinkle over top
  1. 1/4 t Red Star Premier Cuvee yeast
Let sit for at least 15 minutes, and up to an hour.  Stir well, and use the funnel when ladling ginger ale into bottles.  Leave a little air space at the top.  Squeeze bottle gently to bring liquid all the way to the top, and cap tightly.

Your soda will ferment (and therefore carbonate) over the next 2 - 3 days.  It will probably take at least 24 hours before you see any activity.  The first signs are bubbles collecting on the sides of the bottle near the top.  Then the air space will re-appear at the top, and the sides will straighten. Shortly after, the bottle will start to become rigid, like an unopened bottle of soda from the store.  To some extent, the longer the fermentation continues, the more carbonated the drink will become.  Of course, as the pressure increases, so does the chance of an explosion!  I wait 24 hours (no more, no less) after the bottles first becomes rigid, and then move them to the refrigerator.  The low temperature effectively halts the fermentation, although if the bottles warm up again, fermentation will resume.  The total time from preparation to refrigerator is about 48 to 72 hours.  (For the nervous among you, don't stop early either, or your soda won't have much in the way of fizz!)

If you used the coffee filters, your ginger ale should end up mostly clear, although there will always be some ginger + dead yeast sediment in the bottom of the bottle.  If you skipped the coffee filters, it will be cloudier (but still delicious).  Try to pour gently, and you can leave most of the sediment in the bottom of the bottle.  Grab yourself a glass of ice, and enjoy!

According to my measurements, the ginger ale starts with enough sugar to generate 5% alcohol by volume, if it were fermented completely dry.  In practice, very little of the sugar is actually converted to alcohol.  Following the recipe above, there's so little alcohol I can't measure it when I transfer the bottles to the fridge.  I'd say it's less than a quarter of one percent.  There's probably more alcohol in a mouthful of beer or wine than in a whole bottle of my ginger ale, but still, use your best judgement.

The possible variations are almost endless.  All sorts of citrus flavorings would be welcome additions, and I've actually contemplated building a ginger ale on top of lemonade or limeade.  (You'd have to reduce the amount of added sugar, and probably eliminate the citric acid.)  One recipe I saw included spices like black pepper and cayenne.  And my mom suggested a vanilla ice cream - ginger ale float, which made me consider adding vanilla to the mix (though I'm not sure how, since I don't think the flavor extracts into water very efficiently).  Finally, you could double the sugar and start the fermentation with the bottles unsealed.  When you reached 5% alcohol, you could seal them up and end up with alcoholic ginger ale, which sounds fun.  (This would generate more sediment though;  I'm not sure how to deal with that.  You could do the primary fermentation in a separate vessel before bottling, but that's a good bit of extra work.)

I started this recipe from several excellent sources on the web (Jerry Halstead, Mark Sexauer, Jeffrey Morgenthaler), and refined it with a couple of rounds of experimentation.  I hope you enjoy it!  And I'd love to hear of any great variations you come up with.

12/12/2009

Acidified Austrian Potato Salad

I love potato salad (of all types), but I have a problem:  mine always ends up half way to mashed potatoes by the time I'm done.  I guess there's a magic moment when the potatoes are tender but will still hold their shapes, but I never find it.  In an effort to avoid crunchy potatoes, I always overcook them.

However, I learned from Cook's Illustrated that potatoes respond to acid the same way beans do.  That is, acidic conditions keep the cell walls of beans from breaking down and becoming tender, and (slightly) basic conditions promote faster "cooking".  But potatoes cook a lot faster than beans, so instead we can use a little bit of acid -- about 2 T per quart -- to protect them from overcooking.  Conveniently, they seem to cook to the perfect tender-firm texture for potato salad, and then just hold there for another 5 minutes or so!

This particular recipe is similar to a German or Austrian style potato salad, but the same technique would work for a vinaigrette- or mayonnaise-based salad.  Still, this one is well worth a try -- it's got great flavors, and it's actually pretty healthy.

In a 12-inch skillet, bring to the boil

  1. 2 pounds Yukon Gold or other potatoes, peeled and cubed
  2. 1 c chicken broth
  3. 1 c water
  4. 1 t salt
  5. 1 T sugar
  6. 1 T vinegar (scant)

Reduce heat;  cover and simmer until tender, about 15 minutes.  Uncover and increase heat for 2 minutes to reduce liquid to about 1/2 cup.  (If you have more or less, you'll have to drain the potatoes, measure the liquid, and then discard some or supplement with water.  If it looks like about 1/2 cup though, just dump it all in!)  Mash together

  1. 1/2 c potato cooking liquid
  2. 1 T vinegar
  3. 1 T Dijon mustard
  4. 1/4 c vegetable oil
  5. 1/2 c cooked potatoes

Fold in

  1. remaining potatoes
  2. 3/4 c finely chopped red onion (1 small)
  3. 2 T minced cornichons or kosher dill pickles
  4. 2 T minced fresh chives
  5. salt and pepper to taste

Serve warm or chilled.

12/02/2009

Basic beans -- Lentil Chili

My first exposure to lentils was in a sunny plaza somewhere in Spain;  Toledo, I think.  I hadn't been eating all that well lately -- Spanish food has some spectacular highs, but then sometimes you get a bowl of tiny fish, fried whole, and you don't really feel like bones and scales for lunch.  So I was hungry, but this lentil stew was still fantastic -- deep and rich and savory and comforting, even if you (like me) had never had lentils before.  Although the details have faded by now, I keep trying to recreate that stew.  I think I'm passably close now.

This recipe started life as a meatless "chili" in Bon Appetit, and the first time I made it, the lentils never totally softened up -- they were still a little crunchy.  It turns out that beans of all types are sensitive to pH -- in acidic conditions they stay firm, in basic conditions they go soft.  So if you're cooking dry beans, you want to hold off on adding any acidic ingredients (like the tomatoes in this recipe) until the beans are already soft, or you may be waiting a very, very long time.  (Or eating crunchy beans.  Yuck.)  For insurance, you can also add a tiny pinch of baking soda (like 1/16 t, or less) to ensure the water is not acidic.  (Don't add much, or you'll likely get an off, soapy taste from the soda.  Also yuck.)

I also added meat to the recipe -- in Spain, "vegetarian" is generally interpreted as "with less ham".  The Toledo stew probably featured (hard, cured, Spanish-style) chorizo, but Italian sausage or ground beef or even bacon would add a welcome richness.  The ascetics and vegetarians among you may leave it out, of course.

In a medium-large pot, brown

  1. 1/2 lb Spanish-style chorizo (or other sausage)

If you omit the meat, you'll need 2 t olive oil instead.  Now add

  1. 1/2 c chopped onion

and saute until slightly softened.  Stir in

  1. 2 cloves garlic, minced
  2. 1 T mild ground red chile, such as New Mexico, or more to taste
  3. 1 T ground cumin
  4. 1 t dried oregano

You can find bags of ground chile powders for cheap in the Mexican foods section of most markets.  I've found the heat can vary considerably from batch to batch, so start slowly and add more if you need it.  I've substituted California chiles when I can't find New Mexico, but they're generally hotter.  If your pepper is very mild or you like things very hot, you may want to add some cayenne pepper as well, say 1/8 t to start.  Now stir in

  1. 4 c water, plus more as needed
  2. 1/4 c red wine (optional)
  3. 1 c dried brown lentils, rinsed
  4. small pinch (< 1/16 t) baking soda

Simmer for 15 minutes, or until the lentils are tender.  Stir in

  1. 1/3 c tomato paste (that's most of a 6 oz can)

Continue to simmer uncovered until chili is thickened and lentils are tender, about 15 minutes.  Add water as needed if it gets too thick.  Before serving, stir in

  1. 1/3 c sliced green onions

Top with additional green onions and sour cream (if desired) for garnish.  Serves 4 for dinner (3 if you omit the meat).

11/23/2009

Like oil and water

Like oil and water -- that's how I get along with French cooking.  Not that I don't respect the French.  But many of their best dishes require exacting technique, and I'm usually too lazy or too klutzy for anything that precise.  So while my good friend Brian can whip up a lovely vinaigrette the proper traditional way, I was all too happy to discover a cheat.

Most French sauces that blend oily things and watery things have the benefit of egg yolk to hold them together -- hollandaise, bearnaise, mayonnaise.  The lecithin in the egg acts as an emulsifier to allow one of the liquids to "dissolve" in the other, much like soap allows cooking grease to "dissolve" in dish water.  Vinaigrettes are not so lucky -- they have oil, vinegar, and maybe little mustard.  (The mustard helps a little, but not nearly as much as egg yolk.)  So getting a smooth, relatively stable vinaigrette requires adding the oil very slowly and whisking quickly, so that it's so finely broken up it takes at least a few minutes to separate out again.  Too much work.

The folks at Cook's Illustrated discovered, however, that a little dab of mayonnaise from the jar in your fridge will make the vinaigrette emulsify quickly and remain stable for more than an hour.  You can be fairly sloppy about your whisking, or even dump everything in a jar and shake, and it still comes out nice.  That's science I can use.

The basic proportions go like this.  If you're diligent with the whisk, the vinaigrette will be smoother, and thus taste less tart -- you can get away with the lesser amount of oil.  If you're lazy like me, I'd recommend 4 T oil.  The "acid" could be wine vinegar, balsamic, lemon juice, etc.

  1. 1 T wine vinegar (or other acid)
  2. 1/2 t mayonnaise (regular or light)
  3. 1/2 t Dijon mustard
  4. salt and pepper
  5. 3 - 4 T extra-virgin olive oil (or other oil)

Combine everything but the oil thoroughly, then whisk in the oil.  Although I haven't tried it, I bet you can get away with dumping it all in a jar and shaking thoroughly too.  You don't have to measure the mayo either -- a little dab should be about right.

Cook's offers a half-dozen variations on this theme:  some shallot, some garlic, some herbs, some citrus zest.  But once you know the proportions above, you can really make the rest up as you go along.

Incidentally, contrary to vinaigrette's reputation, this isn't a very "light" dressing -- it's mostly oil.  It should have about 180 fat calories per 2 T serving.  On the other hand, I made homemade Ranch the other night, and between the lite mayo and the 1% buttermilk, I figure it had quite a lot less fat in it than most of the commercial dressings in my fridge -- somewhere south of 30 fat calories per serving.  (And it tasted good, unlike "lite" Ranch.)  But that's the subject of another post...