Tag: lemon juice

Delightfully Bitter Marmalade from Seville Oranges

Just as I’d imagined, orange trees lined the streets of Sevilla, Spain, where I found myself for a few hours several winters ago. As I reached for a fruit though, my friend stopped me: The oranges of Sevilla belong to the government. I could be arrested for picking one off a tree—although there are 25,000 such trees in Sevilla.

Instead I picked one off the ground. This was the first time I’d held a Seville orange—or bitter orange, or sour orange—the orange of British marmalade, and the only kind of orange Europe knew for five hundred years. How was Citrus aurantium different from the navels I knew so well?

This orange appeared more squat, broader than tall, with a slightly indented stem end. There was, of course, no navel at the blossom end. The skin was bumpier and had a lovely aroma a little different from that of sweet oranges. I furtively peeled the fruit, half hiding it in my coat. The peel was thinner than a navel’s, rougher inside, and easy to remove. I quickly ate the flesh, spitting out the seeds. It seemed neither bitter nor especially sour. In fact, it tasted rather bland. Had I eaten a true Seville orange, a milder variety of C. aurantium, or some unfamiliar variety of sweet orange (C. sinensis) growing in Sevilla? My friend couldn’t tell me.

The soon-to-be-published Joy of Jams, Jellies, and Other Sweet Preserves wouldn’t be complete without a recipe for Seville orange marmalade, but I finally accepted that the book would always be incomplete in multiple ways; I couldn’t be an expert on preserving all the world’s fruits. After all, I seldom strayed far from my home in Oregon, and Seville oranges simply weren’t available there. The oranges of Seville were all exported to Britain for marmalade.

Although nineteenth- and twentieth-century American cookbooks offered recipes for marmalade made from sweet oranges and other fruits, the authors seldom mentioned bitter oranges. That’s because practically the only Americans who had access to bitter oranges, until recently, were those who lived in southernmost areas of the country (or near West Indian grocery stores in places like New York City). Before the Spanish had ever tasted sweet oranges, they planted bitter ones in warm regions of the New World. In Florida, the trees went wild. When Florida’s commercial citrus industry got underway in the nineteenth century, hardy bitter-orange seedlings were used as rootstock for sweet orange scions, but the seedy, sour, bitter fruit had no commercial value. The bitter-orange trees continued to thrive in the woods, though, and in both Florida and California gardeners could collect bitter oranges when old rootstock would outlive scion wood. In Arizona, according to David Karp, residents used to pick bitter oranges from ornamental street trees and ship them to Canada, where home cooks maintained a tradition of making of British-style marmalade.1 But most U.S. residents knew oranges only of the sweet species, especially California navels and Florida Valencias.

Happily for home preservers, things have changed. In 2010 David Karp reported on a new eighty-acre bitter-orange orchard situated, appropriately, in Seville, California. A company called Vita-Pakt, Karp said, was making most of the fruit into a base for commercial marmalade makers, and also producing juice for Caribbean sauce makers and brewers of Belgian-style white ales. And some of the oranges were being sold to the fresh market.2

So when I was planning a trip to Portland last month, to talk about pickles in the Incredible Edible Garden at the Yard, Garden and Patio Show, and considering what else I might accomplish while in the city, I looked at the gray winter sky and thought citrus. In my part of the state, I can buy navels, mandarins, and even tangelos, but those are generally all the orange-colored citrus that’s available in local supermarkets. In the big city, though, one of the fashionable new supermarkets I’d heard about would surely have Seville oranges.

And that’s how I ended up in New Seasons Market, gawking at skinny legs in skinny jeans and astonishing price tags and wondering if the obesity epidemic might be ended simply by doubling food prices everywhere. Even more interesting than the svelte shoppers, though, was the produce section. I walked round and round the citrus area, astounded at the variety, which included not one but two kinds of kumquats and nearly every other sort of citrus I’d ever read about except for Bhudda’s hand, which perhaps was actually there somewhere waggling a finger at me.

I found the Seville oranges. They looked just like the oranges I’d seen in Sevilla, and they were in perfect condition–firm, oily-skinned, and aromatic. The price of two dollars per pound would have been a lot to pay for eating oranges, but I needed only a few bitter ones to make a year’s worth of marmalade. I bought a bagful.

At home that night my husband and I shared one of the oranges. Again: strong, distinct aroma; loose rind; seeds. But, surprise! The flesh was very sour and rather bitter besides. I can’t explain why these oranges were different from the one I tasted in Spain; perhaps they were of a different variety, or perhaps the difference was in growing conditions or the maturity of the fruit. In any case, I knew that the California-grown bitter oranges would be perfect for marmalade.

I consulted my British preserving books and, especially, C. Anne Wilson’s Book of Marmalade: Its Antecedents, Its History and Its Role in the World Today (New York:  St. Martin’s, 1985). I found, interestingly, that most old and newer recipes included the juice of a lemon. Why would you need lemon juice in sour orange marmalade? Not for pectin, as many people think; bitter oranges have plenty of pectin, and lemon juice has very little. In all citrus fruits, the pectin is mainly in the peel and pith and around the seeds. Lemon juice is added to jams and jellies because the acid helps the pectin do the work of jelling. Perhaps lemon juice was included in orange marmalade recipes because, as I’d learned already, not all Seville oranges are particularly sour. For the sake of tradition, I decided to add lemon juice to my marmalade.

I also decided to include the mildly bitter albedo, the white part of the orange peel, because in the oldest recipes cooks always included it. If they left out any part of the orange, in fact, it would have been some of the outer orange rind, where bitterness as well as aroma is concentrated.3

The final recipe turned out much like my recipe for sweet orange marmalade in The Joy of Jams, Jellies, and Other Sweet Preserves, except that the sweet-orange recipe combines oranges and lemons, peels and all, in imitation of the true . . .

Seville Orange Marmalade
Makes about 5 pints

2¼ pounds (about 8) Seville oranges
9 cups water
9 cups sugar
¼ cup lemon juice

Halve the oranges, squeeze out the juice, and strain it, reserving the seeds and membranes. You should have about 1½ cups juice. Reserve it in a covered container in the refrigerator. Scrape any remaining membranes from the peels (if you’ve used an electric juicer, they will be pretty clean). Tie the seeds and membranes in a piece of cheesecloth. Cut the peel halves in half again, and then cut the pieces crosswise into slivers.

Put the peel shreds and water into a large preserving pan, and add the water and the cheesecloth bundle. Simmer the mixture uncovered for about two hours, until the peel shreds are tender, and then turn off the heat. Remove the cheesecloth bundle to a bowl, and leave the bundle until it has cooled enough to handle. Then squeeze it firmly. Return the liquid to the pan.

Add the sugar, the reserved orange juice, and the lemon juice to the pan. Bring the mixture to a boil, stirring to dissolve the sugar. Boil the mixture to 221 degrees Fahrenheit or until the syrup mounds slightly in a chilled bowl. Remove the pan from the heat, and let the marmalade cool in the pan for several minutes, so the peel shreds won’t float in the jars. Then transfer the marmalade to pint or half-pint sterilized mason jars, leaving ¼ inch headspace. Add lids and rings, and process the jars in a boiling-water bath for 5 minutes.

Remove the jars to a rack or pad to cool, and leave them undisturbed for a day or longer. Jelling will occur gradually over this period.

The finished marmalade should be softly jelled and spreadable, like jam. You’ll find it quite bitter, but also sweet and sour and chewy—a wonderful, grownup topping for morning toast, a complementary filling for chocolate layer cake, or a flavorful glaze for grilled meat. (My husband is begging for smoked gouda to eat with the marmalade. He fell asleep last night imagining the taste.)

1. “Sour Oranges Find Sweet Spot in California.” Los Angeles Times, January 13, 2010.
2. Ibid.
3. Despite what cookbooks and cooking teachers may tell you, the albedo of the sweet orange has no bitterness at all. Some may say that the bitterness develops only with heating, but if you boil the albedo of sweet oranges after removing every bit of the orange part of the rind, you’ll find that no bitter taste develops. When recipes say to leave out all the white part of the peel, the reason involves appearance, texture, or volume, not bitterness.

A New Bottled Lemon Juice: Fragrant and Sulfite-Free

After reading “Real Lemon versus ReaLemon,” Harry Merzian of Dream Foods International sent me a sample bottle of his company’s Italian Volcano Lemon Juice. This juice is not made from concentrate but squeezed from fresh-picked lemons, which are organically grown near Mt. Etna in Sicily. Instead of preserving the juice with sulfites, Dream Foods “gently” pasteurizes it. Once you open one of the 1-liter glass bottles, Harry says, the juice will keep for 30 days in the refrigerator.

My husband, my daughter, and I did a comparative tasting of Italian Volcano Lemon Juice, ReaLemon, and the strained juice of an organically grown lemon. (I thought the lemon was from California, via the supermarket, but my daughter now tells me that a local friend grew it in her hothouse. In either case, the lemon was almost certainly a Eureka or a Lisbon.) My husband and my daughter, for both of whom the tasting was blind, could immediately tell which juice was which. Whereas the ReaLemon was cloudy, pale, and notably bitter, with the aroma of added lemon oil and a slight but unpleasant aftertaste, the fresh lemon juice was clear and yellow with a mild aroma, a balanced sweet-tart flavor, and no bitterness. The Italian Volcano had to be the one with a pinkish-brown tinge. This juice was extremely aromatic, much more tart than the other two, a little sweet, and only mildly bitter. To me, the Italian Volcano tasted a bit like grapefruit juice.

The strong aroma of Italian Volcano comes from the lemon juice itself, Harry says. No oil is added, and the pressing method doesn’t allow accidental inclusion of oil from the rind. The Sicilian lemons must be like no lemons I’ve tasted before. Harry credits the volcanic soils.

Italian Volcano isn’t standardized for acidity. Harry says the pH (pH is a measure of acidity different from percentage of titratable acid) ranges from 2.2 to 3.6. I’ve just tested the pH of the juice Harry sent as 2.4, which is close to results I’ve gotten in the past for fresh lemon and lime juice and various kinds of vinegar. To my husband, my daughter, and me, the Italian Volcano tasted more acidic than it actually was.

Because of its neutral flavor, fresh California (or Oregon) lemon juice would generally be my top choice for canning. But Italian Volcano would be excellent in many desserts and in lemonade and cocktails, and it would be preferable to ReaLemon in canning if anyone with an allergy to sulfites might eat the canned food. Do keep Italian Volcano’s variable acid level in mind.

Dream Foods International was founded in 1998 by Adriana Kahane, who as an MBA student at the University of Southern California studied the feasibility of importing Sicilian citrus, especially blood oranges. The company today imports only juice, lemonade, and limeade, not fresh fruit. For more information about Italian Volcano juices, visit the website at www.dreamfoods.com.

How to Titrate Wine, Vinegar, Verjuice, or Lemon Juice

Although I’m providing these instructions now because I promised to do so in my recent discussion of lemon juice (“Real Lemon versus ReaLemon,” April 19, 2011), I took most of the pictures you see here more than a year ago, after someone asked me for advice in using the strong cider vinegar from her boyfriend’s orchard. The vinegar had tested at 10-percent acid. I checked with an Extension agent I know: “To use 10-percent vinegar in a pickle recipe calling for 5-percent vinegar, you cut the vinegar with an equal amount of water, right?” No, said the agent. She would never tell anyone that it was okay to use any vinegar not commercially labeled as 5-percent acid. How could the woman know her boyfriend’s vinegar was 10-percent acid? I pressed, but the agent was firm. People should always get their pickling vinegar from a store. You just can’t trust regular people to know how to titrate vinegar. Well, my husband does titration, as do a lot of home winemakers. The process is simple, and the equipment and supplies—a graduated 100- or 250-milliliter cylinder, a graduated 10-millilter pipette, a 250-millimeter buret and stand, a 250-millimeter flask, distilled water, phenolphthalein indicator, and .2N or .1N sodium hydroxide—together cost only about $120, or less if you choose plastic instead of glassware. The chemicals are available at brewing- and winemaking-supply shops, and the glassware from science suppliers.

Here are the steps in titration:

1. Bring some distilled water to a boil to drive off any carbon dioxide. You’ll need a little less than ½ cup water per test. Measure 100 milliliters water in a graduated cylinder. Then pour the water into a small flask.

2. Draw 5 milliliters wine, vinegar, or juice into a pipette—a glass tube with a very narrow opening at the bottom and a wider one at the top. You can draw up the fluid either by putting the top of the tube in your mouth and sucking or by using a rubber bulb made for the purpose. Then put your finger firmly over the top opening, and check the fluid level. Do you have a little more than 5 millimeters? If so, lift your finger to drain a bit out. Because the pipette is so skinny, this is a very precise way of measuring.

3. Hold the pipette over the flask of water, and lift your finger to let the wine, vinegar, or juice drain out. Add three drops of phenolphthalein indicator solution. Phenolphathalein is the ingredient that made Ex-Lax useful for acid-base experiments when you were a child.


4. Now you’re going to use the buret. It’s a graduated glass tube, on a stand, with a small lower aperture and a stopcock. Pour .2N sodium hydroxide into the buret to near the top of the numbered scale. (Scientists read the N as “normal.” If you’re using .1N sodium hydroxide instead of .2N, see the paragraph following this. Also, keep in mind that sodium hydroxide, however normal, is very corrosive. You don’t want to suck it up with a pipette.)

5. See how the surface of the fluid in the buret curves, like a contact lens? This curve is called a meniscus. Record the number at the bottom of the meniscus. 

6. Now turn the stopcock so the base solution in the buret slowly drips into the indicator solution while, with your other hand, you swirl the flask. As each drop of base solution falls into the flask, a spot of pink may briefly appear. As you continue adding the base solution, the pinkness will take a little longer to dissipate. Add the drops slowly, and keep swirling. As soon as the liquid in the flask turns a uniform pale pink, stop adding drops. If you wait for the fluid to turn hot pink you’ll have gone too far, and your results won’t be accurate.

7. Record the level of the fluid remaining in the buret. Then record the difference between this number and the one you recorded in step 5.

8. If you’re measuring acetic acid (in vinegar), divide the difference by 4.16. If you’re measuring citric acid (in lemon or other citrus juice), divide the difference by 3.90. If you’re measuring tartaric acid (in wine or verjuice), divide the difference by 3.33. The result is the percentage of acid in your sample.

I could give you formulas for figuring out the percentage of acid regardless of the size of your sample or the normality of your sodium hydroxide, but the formulas might confuse you as much as they confuse me. If you can’t find .2N sodium hydroxide, you’re likely to find .1N instead. In this case, just double the divisor in step 8. If you start with a 10-milliliter sample instead of a 5-millimeter sample, do the same: Double the divisor. If you use .1N sodium hydroxide and a 10-millimeter sample, multiply the divisor by 4.

See, that wasn’t so hard, was it? Now, for practice and to ensure accuracy, repeat the titration, preferably twice. If you have any trouble, watch the very detailed video on titration technique at http://www.youtube.com/watch?v=9DkB82xLvNE.

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Real Lemon versus ReaLemon

Home preservers often wonder why USDA preserving recipes calling for lemon juice specify that the juice should come from a bottle. In most grocery stores the only such product used to be ReaLemon, which is made from concentrate and preserved with sulfites. Today a few competing brands of lemon-juice-from-concentrate are available, with similar assortments of preservatives. To most discerning cooks, ReaLemon and its imitators don’t taste quite real, and to people allergic to sulfites these products may be a health hazard. Bottled fresh lemon juice, with juice from Sicily or Peru, is available at some fancy grocery stores, but it also contains sulfites. Why shouldn’t home preservers use fresh lemons, which are inexpensive and available year-round in every supermarket? Is ReaLemon really better than real lemon?

Extension agents explain that lemons vary in their acidity, and that bottled lemon juice does not. To make sure your jam or your salsa–or, especially, your lemon curd— reaches a safe level of acidity, you should always use the bottled stuff, say the home economists. I decided to find out whether they’re right.

I first researched laws regarding bottled lemon juice. The Code of Federal Regulations (Title 21, volume 2, revised April 1, 2010), includes this FDA rule: Lemon juice prepared from concentrate, like ReaLemon, must have “a titratable acidity content of not less than 4.5 percent, by weight, calculated as anhydrous citrus acid.” Citric acid is the main acid in lemons. Lemons also contain some malic acid, but it usually isn’t measured separately. The ascorbic acid, or vitamin C, for which lemons are justly valued is destroyed by heat and so ignored in discussions of food processing. For our purpose here, we can say simply that lemon juice made from concentrate must have an acid level of at least 4.5 percent, and that the law allows this acid level to vary.

Hmmm. Even if the law allows a variable acid level, a manufacturer would settle on a standard, right? In the opinion of my husband, a chemist, that standard would be 4.5 percent. After all, water is cheap! Why would ReaLemon use more lemons than necessary?

I asked the folks at ReaLemon whether they standardized the acidity of their lemon juice and, if so, what their standard was. Here is their reply: “ReaLemon meets or exceeds the FDA standard of identity for lemon juice, which is 4.5% w/w.” This reinforced my husband’s opinion: ReaLemon had a standard acid level, and it was 4.5 percent.

We decided to test this hypothesis. I bought a bottle of ReaLemon, and we titrated the juice (I’ll explain in another post how to do this). ReaLemon tested at 4.9 percent—the “natural strength” of lemon juice, according to the label. The company rose in our estimation. They were exceeding a minimum standard!

If lemon-juice-from-concentrate is at least 4.5 percent acid, and sometimes 4.9 percent acid, what is the natural range of acidity in lemons? I posed this question to David Karp, a fruit researcher at the University of California, Riverside, who also writes for the Los Angeles Times. David referred me to Walton Sinclair’s Biochemistry and Physiology of the Lemon (University of California, 1984), a four-inch-thick summary of all scientific research on Citrus limon.

According to the research, some lemon varieties are more acidic than others. Lemons of a single variety can vary in acidity depending on the local soil and climate, the rootstock on which the tree is growing, the amount of fertilizer applied, and the season in which the lemons were picked. Lemons and other citrus fruits grown in hotter places, for example, are generally less acidic than those grown in cooler places. Both potassium and nitrogen fertilizers tend to increase acidity levels. New Zealand lemons are less acidic than California lemons, and California lemons are less acidic than Sicilian lemons.

Even a single lemon can show variations in acidity, depending on when you do the testing and from what part of the fruit you take the juice. California lemons increase their acid levels almost 25 percent during curing–that is, in the weeks of storage after harvest. One study found that juice from the stem end of a lemon is slightly more acidic than juice from the blossom end, and another study found that juice from the core area is slightly more acidic than juice from the periphery.

If all these variables make you think the home economists are right, think again. Although lemons vary in acidity, they generally don’t vary much. The least acidic lemon found among all those tested in dozens of studies, an uncured Eureka from California, had an acid level of 4.53 percent. The most acidic uncured Eureka tested at 6.50 percent, and cured Eureka lemons ranged from 5.71 to 7.42 percent. Lisbon lemons from California varied less, from 4.79 to 4.86 percent acid before curing and 5.25 to 5.32 percent afterward.

Florida lemons vary no more in their acidity than California lemons. In one Florida study, samples ranged from 5.16 to 6.41, in another from 5.24 to 5.92.

If you live outside the United States, the lemons in your market may be more or less acidic. In New Zealand lemons averaged only 4.9 percent acid, and in Italy lemons tested as high as 8.1 percent acid. But you won’t find lemons from New Zealand or Italy in Safeway or Albertsons.

Note that I’m not counting Meyer lemons as lemons. A cross between a lemon and an orange, the Meyer is relatively low in acid. Meyer lemons sampled in July averaged 2.4 percent acid in one study; those sampled in February and May averaged 4.1 percent acid.

With all this information before me, I guessed that the juice of a lemon from one of my local grocery stores would test at somewhere around 6.0 percent acid. It would almost certainly be a Eureka or a Lisbon (the fruits of these two varieties are hard to tell apart) or a clonal selection of one or the other. If it were a Eureka, it might be a little more acidic than 6.0 percent; a Lisbon might measure only about 5.0 percent.

So I bought a lemon, and my husband and I titrated the juice. It tested at 6.2 percent acid. Eureka! (Probably.) We drank some of the juice, too, and compared the taste with that of ReaLemon. The natural lemon juice was much less bitter (ReaLemon, like other varieties of bottled lemon juice, contains oil from the peel) and noticeably more sour.

Provided you start with regular lemons rather than Meyers, then, substituting fresh lemon juice for bottled in canning should be entirely safe, although the finished product might end up a little more tart than it would with bottled lemon juice.

Are you adding lemon juice to jam or jelly? This is done not for safety, generally—nearly all fruits are acidic enough for safe canning—but to ensure that the jam or jelly will jell. You can add a little less lemon juice than a recipe specifies if your fruit is quite tart, or a little more if you want a stronger gel.

If you’re canning tomatoes, the acidity of your lemons shouldn’t be a concern. Nearly all tomatoes are acidic enough to can without added acid. If yours are unusually dull in flavor, follow the USDA recommendation: Add 1 tablespoon lemon juice per pint of whole, crushed, or juiced tomatoes. Or, if you like, add more.

Recipes for canned salsa call for quite a lot of lemon juice (or lime juice, or vinegar). If you’re using several fresh lemons, their acidity will average out, and the average will almost certainly be higher than 4.5 percent. By using fresh lemons you may risk making your salsa a little too tart, but you can minimize this risk by using low-acid, paste-type tomatoes, such as Roma, which provide the additional advantage of making salsa thicker.

A particular concern of many home preservers is the safety of fresh lemon juice in canned lemon curd, a tart, buttery custard that’s used as a dessert topping and filling and as a spread for toast, pancakes, waffles, and so on. It’s essential to have a high level of acid in a protein-rich food that’s processed in a boiling-water bath. Home economists say that canned lemon curd is safe only if the lemon juice comes bottled, but remember: American store-bought lemons—the regular kind, not Meyers—are at least as acidic as bottled lemon juice. Besides, you may prefer to use more lemon juice in your curd than called for in the USDA recipe, which, I notice, contains proportionally less lemon juice than does my recipe in The Joy of Jams. You can find the USDA recipe here.

Lemon curd doesn’t need canning, of course. If you put it in a jar in the refrigerator instead, it will keep well for several weeks. You can also freeze lemon curd, and thaw it in the refrigerator for a day before you plan to serve it. If you have a lot of lemons and want to juice them right away, you might freeze the juice so you can make lemon curd as you need it. Lemon juice keeps very well in the freezer.

If you want to give your lemon curd as gifts, though, you may be set on canning it. In this case, be sure to follow the USDA processing instructions. Heat the water to no more than 180 degrees F. before adding the jars, and boil them for 15 minutes, or longer if your altitude is over 1,000 feet.

When you give a friend a jar of your homemade lemon curd or another preserve, you can feel proud that you’ve used the tastiest, freshest ingredients, and confident that your gift won’t prompt an allergic reaction to sulfites.

 

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