Monday, March 28, 2016

More Stuffed Squash

It's the time of year when the winter squash stash is waning and overwintered greens are just maybe waxing enough to start harvesting some nibbles.  (We don't have any such greens in our garden this year, but last year we did!)  What better way to celebrate the start of a new garden season than to take a winter squash and stuff it with some of that new growth?  If you liked our stuffed squash boats, you'll probably dig this version, too.  (If not, thbbbt!)

Kabocha squash, venison, kale, and lentils on a cutting board
Our ingredients: a 2-3 lb Scarlet Kabocha squash, 1 lb ground venison, 1 lb kale, and 1 cup lentils (more than 1 cup pictured here).  NOTE: We only needed about a third of that filling to stuff this squash.  Also, we had to buy kale from the grocery store!  Oh, the humanity...

Roasting a kabocha squash
Cut the squash in half and scoop out the guts, then set the halves cut-side-down in some water on a cookie sheet and bake for 20-30 min until tender. 

We got the squash in early November and had it stored in a corner of our house that was 50-60 °F all winter; it was still in pretty good shape here at the end of March, but some of the seeds were looking like they were about to go all Kylo Ren on us (as in, turn to the dark side, not necessarily fight us with a light saber).  The Johnny's Seed catalog suggests storing this variety at 60-65 °F, so our slightly cooler temps might have decreased its staying power a bit.  Fortunately, the squash meat was still delicious.

Browning venison
Speaking of meat, while the squash is roasting, start browning up that venison...

Cooking lentils
...and cooking those lentils.

Sauteing kale
When the venison is done, put it in a bowl and saute the kale in the frying pan. 

When the kale and lentils are also done, add them to the bowl, too.  Season the whole shebang with salt, pepper, garlic powder, green onion powder, plenty of sage, some lemon pepper, and something labeled Chicago steak seasoning, to taste. Our proportions were probably 1.5 teaspoons of salt, 0.5 teaspoons each of lemon pepper, and steak seasoning, and 1 tablespoon each of everything else.

Stuffed kabocha squash, with cheese
When the squash are done, season them with salt and pepper, too, and stuff them full of the venison-kale-lentil mix.  Pile some shredded cheddar cheese on top.  Katie says, "Hey! Aren't you going to put cheese on that other one, too?" Maybe if you tell me where you hid the Easter candy!

Stuffed kabocha squash, cheese melted
Found it! :-) Ok, put the squash back in the oven to melt the cheese, like so.

Stuffed kabocha squash, with toast and fruit salad
As it turns out, a whole half-squash is more than a serving.  Half of a half squash (that's a quarter squash, for the fractionally-challenged) is better, especially when it means we might also have room for buttered toast and fruit salad.  The buttery flavor of the squash pairs most excellently with the buttery flavor of the toast.  Yum!

There you have it--now you should have no trouble using up your remaining winter squashes before the spring produce starts rolling in!  How's your winter squash stash looking?



Saturday, March 26, 2016

Book Review: Small-Scale No-Till Gardening Basics by Anna Hess

If you follow Anna Hess' blog, or if you've read her books on gardening, you know she's passionate about dirt.  Especially the dirt in which she grows vegetables.  As a result, she's spent a LOT of time turning an eroded, nutrient-depleted patch of ground into an impressively productive garden space on her southwest Virginia homestead.

The cover shows Anna with good dirt, Anna with giant sweet potatoes, and a soybean cover crop in a solarized bed, all on a background of an oat (or ryegrass?) cover crop.  That's two positive outcomes and two tools in the toolbox, if you're counting.
 
Not surprisingly, she's learned quite a bit in the process, and is currently distilling her real-world experience and knowledge of soil science theory into an easy-to-read, highly-actionable eBook series to help you do the same for your garden.  Small-Scale No-Till Gardening Basics is Volume 2 in the series, and is an excellent addition.  By the end of Volume 1, you should know what kind of dirt you're dealing with.  In Volume 2, Anna tells you how to start dealing with it in the context of no-till (or till-once) gardening, which is hands-down the optimal way to build fertility and battle weeds (that is, optimizing speed, cost, and effort).

Accumulating organic matter and strategically using kill mulches are the backbone of small-scale, no-till gardening (after initially remedying things like compaction issues), but how to best deploy those tools depends on your specific circumstances.  The book has very detailed advice for normal-to-overly-wet garden areas, because that's where Anna has the most experience. There aren't as many tips for dry-climate gardens (which, coincidentally, is where we happen to garden), but if you are in a dry climate and not garden-space constrained, Steve Solomon's Gardening Without Irrigation is a useful complementary reference.  (If you are space constrained like we are, you may have to resign yourself to installing some type of irrigation, but minimal tillage is still a good idea.)

One possibly-confusing note is that the "plant-now" lasagna gardening technique mentions squash as a good option in this "shallow-roots-only" system early in the book, but says later on that winter squash are deep-rooted and not suitable for that system. We had to wonder, is summer squash ok and winter squash not ok?  We couldn't find much differentiation between winter squash and summer squash root systems, except slide 93 of this random, 241-slide presentation, which does indeed suggest that winter squash cultivars have deeper root systems than summer squash cultivars.  However, the same slide includes tomatoes with the deep-rooted veggies, while Anna says they work well in the shallow-root-only system.  On the other hand, this book lumps winter and summer squash together.  So, there's a bit of ambiguity on the squash front, but otherwise things seem to check out.

Finally, while there is a ton of practical advice throughout the book, we thought the recommendations might also be usefully represented as a flow chart.   So, although there are many details and insights we couldn't fully capture in a graphic like this, we put together a sort of 'quick-start guide' to help you get your no-till (or till-once) garden started this year:

If you're planning to break new ground for your garden, you might want to consider getting a broadfork.

Our overall conclusion: We liked this book a lot, and although we received a free copy in exchange for an honest review, we feel it's definitely worth the $2.99 price of admission. There are a lot of lessons from the school of hard knocks in these pages, and for all the effort and experimentation it took to learn those lessons (and write them into book form!), three bucks is definitely fair.


Monday, March 21, 2016

Corned Beast Death Match

A couple weeks ago, we wrote that we were pitting the three types of corned venison we've made for past St. Patty's Days against each other in a head-to-head competition. After two weeks of marinating and trash talking in the fridge, Saturday night was finally fight night for our corned beast death match.  Time for the contestants to put their money where our mouth is.

The three curing recipes had identical seasonings except for the liquids; one was a dry rub, one was a brine made with whey, and one was a brine made with apple cider vinegar.  The cooking process was also similar for all three recipes: empty the meat plus all the cure ingredients into an oven-safe bowl, rinse the cure bag out with water, and add additional water as necessary to cover the meat.  Then bake at 350 °F until well-done (meat internal temperatures actually reached 185-190 °F); total time in the oven was about an hour.

The taste tests had two parts: ex-reubo tasting and in-reubo tasting, which are Latin-sounding terms we invented to mean 'out-of-the-reuben (sandwich)' and 'in-the-reuben,' analogous to in-situ (or in-vivo) and ex-situEx-reubo was just a bite of the cooked beast; in-reubo was obviously in the sandwich, along with Swiss cheese, sauerkraut, and thousand island dressing on rye bread.

Somewhat to our surprise, there was a clear winner in this epic battle.  Which recipe emerged victorious?  Read on to find out!

Corned venison
Fresh out of the cure stage, they look pretty similar.  The dry rub is maybe a little darker, and the whey-brined meat is more squishy.

Cooking corned venison
Here they are, warming up for the fight.  A pan of roasted root veggies is ready to make sure any boil overs aren't wasted.

Cooked corned venison
Post-cooking, they also look pretty similar.  There is less foam with the dry rub, and the whey brine had the most.  Not sure if that's significant in any way.

Cooked corned venison, sliced
The internal texture and color looks pretty similar, too, and all were readily edible in the ex-reubo test.  No forced smiles or slipping pieces under the table to the dog were required.  But the whey brine is the clear winner!  It's by far the most tender.  The flavors were pretty similar for all three, too, except the dry rub was more salty.  To be fair, though, the original instructions for cooking the dry rub called for washing off the cure ingredients, cooking it, and letting it sit in a second, less-salty liquid for several hours before doing the final cooking.  For us, the extra required effort does not help the dry rub's case.  The apple cider vinegar-brined meat was also quite a bit drier than the whey-brined version.

Reuben with melted Swiss cheese
Let's move on to the in-reubo test.  Pro tip: melting the Swiss cheese with the broiler helps keeps the slices of corned beast in place.

Reuben sandwiches, cabbage, roasted root veggies
Of course, it wouldn't be a true St. Patty's Day reuben meal without the root veggies and some cabbage to go with it.  It's a lot harder to tell a difference between the different cures in-reubo, but the whey-brined version is still noticeably more tender.  Score settled!  Follow-up question: why is the whey best?  Short answer: we don't know for sure.  The whey has different acids (lactic and citric) than the vinegar (acetic), but also has other things the vinegar brine doesn't have, like lactose and proteins.  Apparently, the combination of ingredients in the 30-min mozzarella whey is a good one for brining meat.

Blueberry pi pie
This photo doesn't have anything to do with corned beast, we just didn't want anyone to think that we missed celebrating the most precise pi day in 100 years (3-14-16 → 3.1416, which is correct to four digits past the decimal point).  The filling is blueberries, which are appropriate for a pi pie because they're spherical.

So, there you have it.  Whey brining is the best way to cure corned beast, in our opinion.  What's your favorite way (or whey) to do it?



Saturday, March 19, 2016

Book Review: How to Bake Without Baking Powder by Leigh Tate

Our last three posts were inspired by Leigh Tate's series on her own blog about baking with ash water, and she's now got an eBook available, too.  The latest volume in The Little Series of Homestead How-Tos includes much more than just baking with ash water leavening, though.  It's a comprehensive guide to understanding what baking powder is and how it works, and how to substitute for both the baking soda and acid components.

Book cover image
Biscuits on a fence for the cover.  We would definitely not be on the fence about eating those biscuits.

Since this is a unabashedly nerdy blog, we cannot, in good faith, mention baking powder without discussing the chemistry.  Briefly, baking powder contains a carbonate (typically baking soda), one or two types of acid (typically sodium aluminum sulfate (NaAl(SO4)2), various phosphate salts, and/or potassium bitartrate (cream of tartar)), and some kind of starch to keep the powder from sticking together.  The acids react with the carbonate to produce carbon dioxide gas when liquid is added and/or when the mixture is heated, depending on which acids are present in the baking powder.  The release of carbon dioxide is what causes baked goods to rise.

So, to bake without baking powder, as the title says, you need to substitute at least the carbonate and the acid components.

As you may know, your kitchen likely contains a lot of options for substituting the acid component, including vinegar, apple cider vinegar, lemon juice, sour cream, yogurt, whey, molasses, and honey.  At least some of those you could probably make on your own if you couldn't get to the grocery store (or didn't want to), or if society had collapsed but you still wanted to make biscuits.  There are also instructions for making some of them, like buttermilk (and cultured buttermilk), along with sourdough starter, which might have fit better in a future volume of yeast-based leavenings, but is nice to have here nonetheless.

Your options for substituting the carbonate component with homemade ingredients are more limited, consisting of essentially potassium carbonate and bicarbonate from wood ashes.  Calcium carbonate from eggshells doesn't work as well, although you might be able to make ammonium carbonate from deer antlers if you're not opposed to setting up a still and happen to have some potash laying around. (Who says you can't eat the horns?)

Of the 54 recipes the book includes, 33 use baking soda, one uses sodium carbonate, 10 use pearlash, saleratus (potassium bicarbonate), ash water, or wood ash, and three use hartshorn (ammonium carbonate).  The other seven get their leavening from eggs or 'emptings,' the yeasty residue that settles at the bottom of brewing vessels, but that, unlike most yeast-based leaveners can apparently be used in quick breads like a chemical leavener. So, in some cases, it's also possible to get by without a carbonate at all. It's worth noting that with a little trial and error, you can substitute some of the wood-ash based leaveners for baking soda, as Leigh did in the series linked at the beginning of this post.

Recipe-Leavening breakdown table
Here's the recipe-leavening breakdown for the book.  Saleratus = potassium bicarbonate; other includes eggs and 'emptings.' (Click it to enlarge.)


It's also really cool to see recipes that are over two hundred years old compiled into the same book as recipes Leigh developed on her own modern-day homestead to make use of her own byproducts, like whey from making goat cheese, and wood ashes from her wood stove.  In that way, it's sort of a living history book. Reading between the lines, there's a story that develops from 'people who realized mixing these random ingredients together made bubbles, which in turn made tastier cookies,' to 'if we mix an acid and a carbonate in these ratios, we'll produce sufficient carbon dioxide to leaven the cookies and not leave a bitter taste.'  Fascinating stuff.

Along the same line of thought as that latter point, one of our favorite parts of the book is the table of recommended ratios for the various household acids and baking soda.  i.e., how much lemon juice do you mix with a teaspoon of baking soda?  How much molasses do you mix with a teaspoon of baking soda to get the same leavening effect?  That's a pretty handy resource that makes substituting ingredients much easier.

The only thing we would have liked to see more of is photographs of the baked goods!  There's a delicious picture of biscuits on the cover, but inside the book, there are only links for a few of the recipes that appeared on Leigh's blog, 5 Acres and a Dream.  On the other hand, fewer pictures to drool over means a lower probability of a shorted-out keyboard, so maybe it was a good strategy after all.

We should mention that we received a free copy of the book, not with any expectations of a review, but, well, for simply being interested enough in the chemistry to contribute some thoughts on Leigh's blog.  That said, we would have gladly ponied up the $2.99 price tag of this book.  It's clear that Leigh put in many, many hours of research on this book, and three bucks is more than fair for that effort.

In summary--How to Bake Without Baking Powder is an excellent reference and we have no qualms about recommending it to everyone.  Readers, start your ovens...ready...go!



Monday, March 14, 2016

Wood Ash Leavening--Biscuit Baking Time!

Last Tuesday, we hypothesized, based on historical tales, that wood ash leachate ("ash water") likely contains both potassium hydroxide and potassium carbonate.  On Saturday, we proved it with a titration experiment.  Today, we find out what it all means with a biscuit baking party.

As a recap, we calculated that the hydroxides in the ash water outnumber the carbonates nearly 3:1, and that one teaspoon of ash water should have the same leavening power as about 1/46 teaspoon of baking soda.  Fortunately, baking with the ash water has turned out to quite a bit better than our prognostications suggested.

This is the recipe that we used as a starting point (and a positive control):

Base recipe:
0.5 cups all-purpose flour
0.125 (1/8) tsp salt
1 Tbs butter
1 tsp apple cider vinegar + milk to 0.25 cups
0.25 (1/4) tsp baking soda

Mix apple cider vinegar and milk to make a faux buttermilk.  Combine flour, salt, butter, and baking soda in food processor and process until butter is cut in.  Combine buttermilk and solid ingredients, mix well, and form into drop biscuits on a cookie sheet.  Bake at 400 °F for 20 min.  Yield: 3 biscuits.  Serving size: 3 biscuits.

To modify it for wood ash-based leavening, we figured we'd need more acid to neutralize the hydroxides.  Also, based on Leigh's experiments, using dry wood ash seemed to work just about as well as the ash water, so we did started with two variations on the base recipe:

Variation 1:
Same amounts of  flour, salt, and butter

1 Tbs apple cider vinegar + milk to 0.25 cups
1 tsp ash water
no baking soda

Variation 2:
Same amounts of flour, salt, and butter
1 Tbs apple cider vinegar + milk to 0.25 cups
0.25 (1/4) tsp dry ashes
no baking soda

We also made a negative control, which was the same as the base recipe, but without the baking soda.  This is what we got:

Ash and ash water biscuits, THL recipe, top view
The 'no leavening' control was the least risen of the bunch, and the baking soda was much better than the rest.  The ash water and dry ash were somewhere in the middle, but, like the calcium carbonate experiments we did here and here, closer to the 'no leavening' than the 'baking soda.'  Still, they made a good lunch, and they're very tasty with cheese.

Ash and ash water biscuits, THL recipe, side view
Here you can see how the textures compare.  No competition for the baking soda...yet.

When we were taste testing these biscuits, we noticed that the biscuit with dry ash had a sort of tangy flavor, suggesting that all the apple cider vinegar hadn't been consumed.  The ash water one didn't, but looking back at our recipe, we realized we actually meant to add 2 Tbs of apple cider vinegar to that one, which would have given us the 6x increase on the original recipe acid that we calculated in the last post.  So, we decided to make another batch with two more variations:

Variation 3:
Same amounts of flour, salt, and butter
1 Tbs apple cider vinegar + milk to 0.25 cups
0.5 tsp dry ash
no baking soda

Variation 4:
Same amounts of flour, salt, and butter
2 Tbs apple cider vinegar + milk to 0.25 cups
1 tsp ash water
no baking soda

Also, as a reality check, we decided to make Leigh's recipe, which had twice the lipid, a lot more ash water, and actually less acid:

Leigh's Recipe:
0.5 cups all-purpose flour
0.125 tsp salt
2 Tbs butter
2 Tbs milk
2 Tbs ash water
0.5 tsp white vinegar

And since we had room on the cookie sheet for three more biscuits, we made another set of the base recipe with baking soda because, frankly, those are the only ones Katie has really liked so far.

Here are the results of the second round:

Ash and ash water biscuits, THL recipe and Leigh's recipe, top view
All of the round two biscuits rose better than the round one biscuits. (Except for the baking soda control, that one was about the same.)  Leigh's recipe beats the pants off of all the variations we devised.  So, either the extra butter makes a big difference, or the extra ash water does (we're betting on the latter).  We did accidentally spill a little extra vinegar into the mix, so it was more like 1 tsp vinegar instead of 0.5 tsp.

Ash and ash water biscuits, THL recipe and Leigh's recipe, side view
It shows in the texture, too.  Both of the biscuits on the bottom earned Katie's seal of approval.

Well, now we've got a conundrum!  More ash water and less acid seems to be what it took to get the leavening effect we were going for.  So, while we calculated that we would need to boost both the ash water content and the acid content in our recipe, the ash water content clearly makes a bigger difference.  What gives?

The first thing that comes to mind is that the hydroxides in the ash water could have reacted with other ingredients in the recipe (i.e. the the butter or the milk), taking themselves out of the equation before the vinegar even had a chance to take a whack at them.  So, it's possible that doubling down on the acid in the recipe wasn't really gaining us anything. 

Similarly, sitting out on the kitchen counter, exposed to the air for a week, might have let the hydroxides react with carbon dioxide from the air, throwing our calculated hydroxide-to-carbonate ratio way off (and underestimating our total carbonate).   We think that's a more likely possibility, because when we tried to titrate the ash water a second time several days later, it took a lot less acid to reach the end points. 



Cracked measuring cup
We also helped increase the surface area of the ash water (i.e., it's opportunity to interact with atmospheric carbon dioxide) by storing it in a polycarbonate measuring cup one night.  By the next morning, there was a crack in the cup and the ash water had run out onto the counter!  Turns out, polycarbonate is not compatible with potassium hydroxide. Now we know!

For what it's worth, we did calculate that if we were able to convert all the hydroxides into carbonates, 1 tsp of ash water would have the leavening power of about 1/22 tsp of baking soda.  Since Leigh's recipe calls for 2 Tbs (6 tsp) of lye water, that's 6/22 tsp of baking soda.  6/24 tsp would be the same as 1/4 tsp, which is what our base case recipe called for.  So, the theory sort of lines up with the experiment in this case.

The only other possibility we can think of is that we did something really wrong in our titration, and we're totally not ready to entertain that idea yet!

So, some final thoughts on ash water leavening: it works!  Just follow Leigh's recipe instead of ours, and make the ash water well ahead of time so that it has time to pull carbon dioxide out of the air, eat through your polycarbonate measuring cups, and/or generally get to know you a little bit before you try to stick it in your biscuits.


Have you ever baked with ashes or ash water?  How did it go?


Saturday, March 12, 2016

Wood Ash Leavening Chemistry--Ash Water Titration

On Tuesday, we established that the process of leaching ash water likely extracts both potassium carbonate and potassium hydroxide.  But we also want to know the relative proportions of each because if we're going to use the ash water for leavening, we have to increase the amount of acid in the recipe to neutralize any potassium hydroxide, if it's present.  Today, we're going to titrate some ash water.

We can approach this task in two ways. We could 1. trudge through it with the bored disdain of an analytical chemistry student ("is it ever going to change color?"), or 2. pull out a bottle of last spring's dandelion wine, blast some banjo music, and turn this nerd party into the best date night ever!  If you've been following this blog for any length of time, you know we're about to down some libations and do some titrations!

Essentially, what we're doing in the titration is to take the ash water, which is very alkaline (high pH) and add a solution of acid a little bit at a time until we get to the point where all of the hydroxide and carbonate are converted to water (from the hydroxide) or water and CO2 (from the carbonate), at which point the water will be very acidic (low pH).  If we keep track of the amount of acid we added, we can figure out how much carbonate we have, and then back-calculate to figure out how much hydroxide.  It's like magic, but better--it's math!

The chemistry that's happening is this:  first, all the acid we add (e.g., hydrochloric acid, HCl) is eaten up by the hydroxides:

KOH +  HCl = H2O + KCl

(That's why, if both are present in the ash water, we need to add more acid to our biscuit recipe to get the leavening effect we want.)  Next, all the acid we add reacts with the carbonate to produce the bicarbonate:

K2CO3 + HCl = KHCO3 + KCl

Finally, all the bicarbonate reacts with the acid to produce carbonic acid, some of which will convert to dissolved CO2, and some of that will convert to gaseous CO2 and bubble out of solution (that's the leavening effect we're trying to get when we combine acid and baking soda in our biscuits!):

KHCO3 + HCl = H2CO3 + KCl

H2CO3 = H2O + CO2,(aq)

CO2,(aq) = CO2,(g)

For what it's worth, the acid that reacts with KOH in the first reaction above could also be H2CO3, which would generate K2CO3 and, if there were enough H2CO3 to go keep it going, KHCO3. So, bubbling CO2 through the ash water, which generates H2CO3 by Le Ch√Ętelier's principle (i.e., it pushes the above reactions backwards), would help boost the leavening power of the ash water.  In the absence of bubbling CO2 , it can help a little to leave the ash or ash water sitting out exposed to the air before using it, because it will absorb CO2 from the atmosphere, to some extent.

What are we looking for in the titration?  This book has a great visualization of what you'd expect to see when titrating carbonates, hydroxides, or a mix of both.  The only trick is that we don't have a pH meter to measure the titration progress directly, so we need a pH indicator (i.e. a molecule that changes color in response to changes in pH) instead.  This site explains that phenolphthalein and methyl orange make good indicators for this titration, while the book linked above says bromocresol green is also good for the second indicator.

What makes an indicator good for a particular titration is if it changes color at the same pH as one of the endpoints we're trying to titrate (carbonates for us).  The chart below shows where the indicators mentioned above change color in relation to the species of carbonate in the ash water.  Our kitchen doesn't have any of the three indicators commonly used in the lab, but we do have some red cabbage juice, which is a cool enough indicator to do both endpoints.  Hooray for cabbage!

Carbonate speciation and pH indicators
Phenolphthalein changes from pink to colorless just as all of the CO32- is used up (endpoint 1, or EP1, at pH 8.4).  Similarly, bromocresol green changes from blue to yellow and methyl orange changes from yellow to red just as all the HCO3- is used up (EP2, pH 3-4).  (Source.) Happily for us, cabbage juice changes from green to blue near EP1 and from colorless to pink near  EP2.  Cabbage juice solutions don't really go completely clear, but they become a very pale purple, and then the first tinges of pink should indicate our endpoint.

Titrations with indicators in general are a little tricky because the color change is always somewhat subjective.  But we can practice on a few solutions of sodium hydroxide and sodium carbonate first, to get a feel for what we're looking for.

But before we can do that, we need a strong acid to titrate our solutions with.  We picked up some muriatic acid (HCl) from Lowe's and diluted it from 31.45 wt% (10 M) to 0.05 M (essentially, 1 teaspoon (5 mL) into 500 mL (a little over 2 cups) of water to make 0.1 M HCl, and 1 cup of that plus 1 cup water to make 0.05 M.  NOTE: if you're following along at home, put on safety goggles and gloves before you start playing with 10 M HCl. Also, HCl doesn't get along very well with almost any metal, including stainless steel.  So, if you're diluting in the kitchen, don't use your nice metal bowls and measuring spoons.  Plastic and glass only for this exercise!

Now, we need some standard solutions. First up: just NaOH (5 g in 500 mL water to make a stock solution), diluted 1:10 (1 teaspoon of the stock solution plus 3 Tablespoons water), and added 1 teaspoon of the indicator solution. Here's the math to show how much acid we expect to need to add.  The smallest plastic measuring device we have is 0.25 teaspoon, so that's what we're going to count our titrations by.

Titration math

Calculated number of 1/4 teaspoon aliquots to add to get to EP1: 20
Calculated number of 1/4 teaspoon aliquots to add to get from EP1 to EP2: 0

Large canning jar of 0.05 M HCl, 1/4 teaspoon measuring device, small canning jar of 1 g/L NaOH in place...ok, ready, go!  1 quarter-teaspoon, swirl, 2 quarter-teaspoons, swirl, 3 quarter-teaspoons, swirl...

Actual number of 1/4 teaspoon aliquots to add to get to EP1: 13
Actual number of 1/4 teaspoon aliquots to add to get from EP1 to EP2: 0
EP 1 + 2 error: -35%
 
Titrating NaOH with hydrochloric acid using cabbage juice as pH indicator
0.05 M HCl added in 0.25 tsp aliquots.  That's the smallest non-metal measuring spoon we have!

Hmm...so, not terribly accurate, (see note at the end of this post) but we would predict all hydroxides and no carbonates, as expected.  The indicator pretty much skipped the blue and purple phases and when straight to pink-ish. 

Second standard solution: just Na2CO3 (5 g in 500 mL to make a stock solution, diluted the same way).  We can to do the same math (substituting the molecular weight of Na2CO3 for that of NaOH to get to:

Calculated number of 1/4 teaspoon aliquots to add to get to EP1: 7.55
Calculated number of 1/4 teaspoon aliquots to add to get from EP1 to EP2: 7.55

And...the results:

Actual number of 1/4 teaspoon aliquots to add to get to EP1: 5
Actual number of 1/4 teaspoon aliquots to add to get from EP1 to EP2: 5
EP1 error: -34%
EP2 error: -34%

Titrating Na2CO3 with hydrochloric acid using cabbage juice as pH indicator
0.05 M HCl added in 0.25 tsp aliquots.


So, similar errors, but again, we would conclude based on the volumes to endpoint 1 and endpoint 2 that we have just carbonate in solution, which is true.

How about a third standard solution, with a mix of the two?  5 g NaOH + 5 g Na2CO3, similar math to get to:

Calculated number of 1/4 teaspoon aliquots to add to get to EP1: 27.55
Calculated number of 1/4 teaspoon aliquots to add to get from EP1 to EP2: 7.55
Actual number of 1/4 teaspoon aliquots to add to get to EP1: 23
Actual number of 1/4 teaspoon aliquots to add to get from EP1 to EP2: 6
EP1 error: -17%
EP2 error:  -20%

Titrating a mixture of NaOH and Na2CO3 with hydrochloric acid using cabbage juice as pH indicator
0.05 M HCl added in 0.25 tsp aliquots.  We went one past our supposed endpoint to see how pink it would turn.

Better, but still large enough errors to make an analytical chemist cringe.  However, feast your eyes on this set of numbers:

Calculated ratio of carbonate to hydroxide: 0.377
Experimental ratio of carbonate to hydroxide: 0.353
Error: -6.5%

Booya!  Less than 10% error is not bad for kitchen chemistry.  It looks like we might be able to use this technique with enough accuracy to figure out relative amounts of hydroxides and carbonates in our ash water.

Now for the real stuff.  We made the ash water by mixing 0.5 cups wood ash (mainly elm) plus 0.75 cups boiling water, mixed well, and left to settle for several days (mainly because of convenience; it was well settled by the next morning).  We tried one titration undiluted, but the ash water turned out to be really strong stuff, so we ended up diluting the ash water 1:10 and titrated that with 0.05 M HCl.  Here's the stats:

Actual number of 1/4 teaspoon aliquots to add to get to EP1: 29
Actual number of 1/4 teaspoon aliquots to add to get from EP1 to EP2: 8
Experimental ratio of carbonate to hydroxide: 0.381
(Experimental ratio of hydroxide to carbonate = 1/0.381 = 2.625)

Titrating ash water with hydrochloric acid using cabbage juice as pH indicator
0.05 M HCl added in 0.25 tsp aliquots.

Whoa!  So, for every 1 molecule of carbonate in our ash water, there are 2.625 molecules of hydroxide. Or, stated another way, the leavening power-influencing parts of the ash water are 72.5% hydroxide and 27.5% carbonate.

What does that mean for baking with ash water?  If we had only carbonates, we would have to add enough acid to convert the carbonate to the bicarbonate, and then convert the bicarbonate to CO2.  But since we know that our acid will first react with the hydroxide, we need to increase the acid on top of that.  If a recipe is starting with baking soda (sodium bicarbonate) and an acid, we would want to double the amount of the acid to get the same effect from the carbonate, and then roughly triple that amount to neutralize the hydroxides.  Or, overall, if we're replacing baking soda in a recipe with ash water, we should have to add six times as much acid as the recipe calls for to get the same leavening effect.

Also, it's probably good to know how much bang for the buck we can expect to get from the ash water.  Although we noted that our quantification isn't great, we were consistently predicting 20-35% less of each component than was actually present.  So, for the carbonates, our titration calculates that there is 0.000492 mol K2CO3 and 0.00129 mol KOH per teaspoon of ash water, which works out to 0.067 g K2CO3 and 0.072 g KOH.  If we multiply those by 1.25 to account for the 20-30% error in our titration, it works out to 0.085 g K2CO3 and 0.091 g KOH.  Since the baking soda (sodium bicarbonate) has a bulk density of 801 kg/m3 (0.801 g/mL), and 1 teaspoon = 4.92 mL, each teaspoon of baking soda contains about 3.94 g of NaHCO3.  Therefore, one teaspoon of our ash water has about the same potential leavening power as 0.022 (1/46) teaspoon of baking soda.  (Actually, it has slightly less leavening power because KHCO3 weighs more than NaHCO3.)

Of course, it will only reach that potential if we add enough acid to neutralize the hydroxide and convert the carbonate to bicarbonate.  As we mentioned above, the best way to do that would be to bubble CO2 through the ash water, which will convert both the CO32- and the OH- to HCO3-. Ideally, we'd do that until the ash water (with a bit of indicator) turned blue.  That would increase the leavening power up to about 0.04 (1/22) teaspoon of baking soda.  The other readily-available way to increase the leavening power would be to boil off most of the water to concentrate the carbonates.
 
With this knowledge in hand, we can move on to the delicious finale.  Stay tuned for more biscuit trials!

 ...
 
Ok, as a follow up, we were slightly disturbed by the absolute errors in our titrations, so we did something that we should have done beforehand--mix up reference solutions to compare colors.  To get the first endpoint is easy--just mix baking soda into water and add the indicator.  All of the relevant species are present as the bicarbonate ion, so the pH is right at the first endpoint.  For the second endpoint, we added 0.25 teaspoons of our NaOH stock solution (5 g NaOH in 500 mL water) to 100 mL of vinegar, which should give a mixture with a pH of about 3.08 (calculations available on request!).

Reference solutions at pH of carbonate titration endpoints
That second endpoint (on the left) is a lot pinker (i.e., lower pH) than what we were calling our endpoint!  No wonder our errors were so large--we should have added a few more aliquots of 0.05 M HCl to each solution before calling it done.  Of course, that wouldn't help the first endpoint much; most of the solutions went from green-blue right to purple.  Guess we better stick mostly to calculating  ratios with this method.  Also, if you ever need a nerdy gender-reveal idea for your future baby, here you go!


Tuesday, March 8, 2016

Wood Ash Leavening Chemistry--An Extraction of Historical Accounts

Leigh over at 5 Acres and a Dream recently did a fascinating series of blog posts on producing leavening from wood ashes (Part 1, Part 2, and Part 3).  The high-level overview is that wood ashes contain potassium carbonate, which can be extracted and used as leavening for quick breads, biscuits, etc., similar to how baking soda is used.

Leigh made some pretty tasty-and-leavened-looking biscuits with her extracted carbonate (and with straight wood ash), but noted that they didn't rise quite as well as the control biscuit (which had baking soda).  There were also a few unanswered questions on the chemistry involved, so we wanted to follow our nerdy instincts and dive into the nitty gritty of what's happening at the molecular level.

First issue: what is actually being extracted from the wood ashes?  Carbonates, we suspect, but is that it?  In our minds, there's a controversy, since the process of extracting carbonates for leavening sounds an awful lot like the process of extracting lye (potassium hydroxide, KOH, in this case) for soap making.  We're especially keen on figuring this out because if both hydroxides and carbonates are present, it will change our biscuit recipe (specifically, we'll have to add more acid to get the leavening effect). Let's compare some descriptions.

 The very cool Caveman Chemistry website says that the major components of wood ashes are potassium and sodium carbonates, but says this of the extract:
"It contains all of the soluble materials which were present in the the ashes to begin with. This could include sodium and potassium chlorides, sulfates, hydroxides, and carbonates."
So, it sounds like both carbonates and hydroxides could be present.  Another account of potash and pearlash production from 1866 is generally consistent with that (despite a distinct lack of cavemen in 19th century North America), but doesn't mention hydroxides:

"Carbonate of potash is generally obtained from wood ashes...the soluble constituents of the ashes are the carbonate, sulphate, phosphate, and silicate of potash and chlorides of potassium and sodium.  The insoluble constituents are carbonate and subphosphate of lime, alumina, silica, the oxide of iron and manganese, and a dark carbonaceous matter."

That same account also describes the process for preparing the potash and pearlash:

"In America, the ashes are lixiviated [extracted] in barrels with lime, and the solution evaporated in large iron pots or kettles, until the mass has become a black color and the consistency of brown sugar.  In this state it is called, by American manufacturers, 'black salts.'  ... To make the substance called pearlash, the mass called black salts...is transferred from the kettle to a large oven-shaped furnace, constructed so that the flame is made to play over the alkaline mass. ... The ignition is in this way continued until the combustible impurities are burnt out, and the mass, from being black, becomes dirty bluish-white, having somewhat of a pearly lustre, whence the name pearlash. The coloring matter is probably in this case manganate of potash."
In a process flow diagram, it would look something like this:

Pearlash historical production process flow diagram
Other soluble minerals (OSM) seemed like a better acronym than Minerals of Unusual Solubility (MOUS). (Warning: obscure pop culture reference.)  You can buy pure potassium carbonate these days, and it's bright white.  To visualize the color of pearl ash, think of this color, but very faint.

So, no mention of potassium hydroxide in the old-time production, but that might be because of the production method.  The CO2 in the combustion gases that are passing over the black salts reacts with KOH to make KHCO3 (or to make H2O and K2CO3); any KHCO3 produced decomposes to K2CO3 in the heat.  So basically, if hydroxides are extracted into the ash water, they don't make it into the pearlash.

But, compare the process of making ash water for leavening with any of several similar descriptions of the process for preparing lye for making soap.  For example, this one:

"Traditionally, one uses an old wooden barrel or lye hopper for this, even hollow treetrunks in some areas. ... In the bottom, put a filter made from a couple of inch depth of twigs, and the same again of straw or hay. This helps ensure the lye comes off moderately clear. Stand the lye barrel up high enough to get a container underneath...and fill it up with those ashes. Add water. ... Leave it all overnight...[then] let the lye run out into your container."

Other descriptions call for adding lime (or slaked lime), which we noted increases the hydroxide yield by converting carbonates to hydroxides by the following reaction:

 Ca(OH)2 + K2CO3 = 2 KOH+ CaCO3

There is also a journal article in the peer-reviewed literature, which claims the ratio of hydroxides to carbonates in their crude ash extracts is 92-to-8, and more anecdotal observations that carbonates don't work very well for making soap (but ash water does) and that crude ash extract by itself doesn't do much leavening.  Therefore, it seems very likely that the crude ash water extract contains an appreciable amount of hydroxides along with the carbonates.

So there's the theory--probably both carbonates and hydroxides are present in the ash water.  Fortunately, we don't have to just sit around, dealing in hypotheticals.  We can experimentally measure the amounts of carbonate and hydroxide in the ash water through the magic of titration. (If you've suffered through an analytical chemistry class in college, we hope you didn't just throw up in your mouth a little bit.)

Wood ash and water extract
O ash water, what mysteries containest thou for us to unravel by the labor of titration?

We'll give you a few days to stew over that and then hit you with a chemistry-dense post interspersed with colorful pictures.



Sunday, March 6, 2016

Corned Beast Recipe Death Pre-Match

Guess what!  St. Patrick's Day is only two weeks away! That means if you're going to corn your own beast for reuben-making this year, it's about time to get started.

It's definitely a tradition around here to corn venison ahead of St. Patty's Day, but we've done it a number of different ways over the years.  And, as much as we hate to admit it, the sad truth is that we don't do much meat corning outside of early March.  So, when we make a  batch and try to compare its flavor and texture to the previous batch, it's a tall order for our meager brains.

How can we resolve this dilemma?  No problem.  Like we did with our french toast, we'll have a tasty corned beast recipe death match and settle the score once and for all.

The three techniques we've used to corn our venison are a vinegar-based brine, a whey-based brine, and a dry rub.  Those are the three that will be cage fighting in our kitchen this year.  Here's the basic recipe:

0.5 lb venison roast

1 Tablespoon salt
1 teaspoon brown sugar
0.5 teaspoon ground black pepper
0.5 teaspoon whole coriander seeds
0.5 teaspoon whole mustard seeds
0.25 teaspoon ground allspice
0.25 teaspoon ground cloves
1 bay leaf, crushed
1 clove garlic, sliced

That's it for the dry rub.  For the whey recipe, we added 0.5 cups of whey from a 30 min mozzarella recipe (made with 2% milk).  For the vinegar recipe, we added 2 Tablespoons of apple cider vinegar, plus water to bring the volume up to 0.5 cups.

Venison, seasonings, brines for corning
From left to right: dry rub, apple cider vinegar-based brine, whey-based brine.

We mixed all the solid ingredients together (except for the meat), then added the liquid (if any) to a plastic bag, then added the meat, too, and gave it a nice massage. We expelled all the air out of the bag, sealed it with a twisty-tie, and put it in a bowl as secondary containment (just in case the bag leaks!) in the fridge.  The recipes we've seen say to flip it once a day, but for us in the past, it's been more like every other day (at best).  It's always still came out pretty tasty.  In any case, at least all three runs will get the same treatment! 


Venison, seasonings, brines for corning, in bag, ready for fridge!
Don't forget to label the bags!


What's your favorite technique for corning meat?  Have you corned meat other than venison (or beef)?