Cookbook:Ice Cream
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Ice cream is a type of churned frozen dessert. This chapter covers ice creams and other churned frozen desserts (e.g. sorbet), but not still-frozen desserts or semifreddi.
Characteristics
[edit | edit source]Structure
[edit | edit source]The structure of ice cream and other churned desserts depends on the specific proportions of ingredients in the base,[1] but it is generally a colloid composed primarily of three parts: ice crystals, tiny pockets of air, and a concentrated unfrozen liquid matrix.[2][1][3][4] As the ice cream base freezes, the liquid water crystallizes out of solution.[2][1] These crystals are what hardens the ice cream and gives it a rigid structure, and their size affects the smoothness of the final product.[2] As the water crystallizes out, the remaining liquid matrix becomes more highly concentrated in all the other components of the ice cream base, such as sugar, flavoring, alcohol, protein, etc.[1][3] These remaining components do not solidify as typical temperatures,[4] and this helps keep the matrix fluid and soft. Tiny air bubbles are studded through this matrix, and fats, proteins, and emulsifiers line and stabilize the liquid-air interface.[1][3]
Texture
[edit | edit source]The microstructure and ingredient proportions as described above determine the sensory character of an ice cream, including hardness, perception of coldness, fluffiness, smoothness, mouthfeel, creaminess, viscosity, etc.[1][5] For example, larger ice crystals will result in a gritty or sandy texture and will make the ice cream feel less cold.[1] On the other hand, smaller ice crystals give a smoother texture,[5][6] and their increased surface area absorbs more heat from the mouth and makes the ice cream feel colder.[1] If the base contains too much fat, the fat may coalesce into large fat globules with an unpleasant greasy texture like that of butter.[3][5] Antifreeze components like sugar and protein often prevent large ice crystals from forming,[1] but in excess they weaken the structure.[3]
Overrun
[edit | edit source]The air bubbles mixed into ice cream are called overrun,[3][7][8] and it is expressed as a percentage of the original base volume.[8][9] For example, overrun of 100% means the ice cream volume has doubled;[9] 1 gallon of base yielding 1½ gallons of ice cream has an overrun of 50%.[8] The overrun affects the density and softness of ice cream,[9] with more air impeding the formation of large ice crystals and resulting in a lighter, softer texture.[1][2][7] However, excessive overrun weakens the flavor and texture of the ice cream.[5][7][9] High quality ice creams can have a very low overrun (e.g. 20%) and have a high quality, dense texture;[5][8] however, ice creams with excessive stabilizers may have an unpleasant, pasty texture without enough overrun.[5] Some regulatory bodies limit the amount of overrun in ice cream. The FDA in the United States, for example, allows a maximum of 100% overrun.[7][9]
The amount of overrun in ice cream is determined by the type of freezing equipment, the starting ratio of liquid base to air in the container, the length of churning time, and the ingredients.[1][5][9] For example, horizontal churners will incorporate more overrun than vertical, and eggs and fat stabilize air bubbles).[1][5][8][9]
Fat
[edit | edit source]Fat, which in ice cream typically comes from dairy as butterfat/milkfat, is critical for both flavor and texture.[3][9] First, as we know, fat carries flavor.[7] Butterfat also helps gives ice cream a rich and creamy feeling,[3][5][8] in part by controlling the size of ice crystals,[4] which is part of what makes dairy-based ice creams generally smoother and creamier than sorbet.[8] However, as mentioned, excessive fat content can cause the buildup of little grains of butter and leave an unpleasant grainy, greasy texture.[5][7][9] Higher fat content tends to make a more compact ice cream with less overrun.[8][9]
In the United States, the FDA requires ice cream to have at least 10% milkfat,[9] but the typical fat content ranges from 10–18%,[7] and very high quality, rich ice creams may contain more with as much as 24%.[8][10] Reduced-, low-, and non-fat ice creams contain much less fat than the standard,[3][2] and these recipes must compensate for this lack by adding additional stabilizers like corn syrup, milk powder, gums, etc.[2][4]
Eggs
[edit | edit source]Some churned desserts incorporate eggs, be they whole or separated out into yolks or whites. The protein and lecithin in egg yolks act as emulsifiers,[9] which help keep the fat and ice particles small and well-distributed in the ice cream matrix.[11] The proteins in egg whites also help to stabilize air bubbles and create a lighter final product, which makes them valuable in sorbet.[12] Egg yolk, especially, will also contribute flavor, especially if the ice cream base is cooked.[2] If the ice cream base is not to be sufficiently cooked, some recipes call for pasteurized eggs to reduce the risk of food poisoning.[9][12]
Sweeteners
[edit | edit source]Obviously, sugar adds sweetness to ice cream, but it is also critical for the texture.[1] Sugar holds onto water within the ice cream base, and the increased viscosity of the ice cream matrix makes it more difficult for ice crystals to form and join together,[4][8] lowering the overall freezing point.[4][5][11] This prevents a gritty texture and keeps the ice cream from getting too hard.[7][8][11] The viscosity also stabilizes the air bubbles in the matrix and adds "body".[1] Too much sugar, however, makes the ice cream overly soft and sweet[1][5][8][9]—balance is key.
Because sorbets contain a high amount of fruit, which can vary in sugar from batch to batch, it's a good idea to use a saccharometer or Brix refractomer when making them.[5][7][8] Both of these tools allow you to measure the amount of sugar in the base and adjust as necessary to achieve consistent results.[8] A saccharometer is a hollow tube that is allowed to float in the liquid at room temperature; it uses the density of the liquid to measure the sugar content on the Baumé scale.[7] Pure water at room temperature is 0° Baumé, and a simple syrup of equal parts sugar and water is 28° Baumé.[8] A refractometer uses light to measure the amount of sugar in a small volume of liquid placed on the instrument; it uses the Brix scale.
The most common sweetener for use in ice cream is refined sucrose (table sugar), which provides a neutral sweet flavor.[9] However, other sweeteners like molasses, honey, glucose syrup, and maple syrup can also be used.[5][9] Invert sugars like glucose syrup may help retard the formation of ice crystals and thereby increase smoothness,[5][7][12] but using more that 5% by weight can result in an undesirable chewiness.[12] When substituting honey for granulated sugar, use about 20% less to account for the different properties of honey.[9] When decreasing sugar in ice cream, you may need to add a stabilizer or texturizer (e.g. gelatin) to compensate for the lost properties.[1] Keep in mind that an ice cream base tastes less sweet after it is frozen.[9]
Milk solids
[edit | edit source]Milk solids in ice cream add flavor and modulate the texture. The protein and sugar content add "chew", bind water, and help retard the formation of ice crystals,[3][7] which helps with smooth texture. However, excess milk solids with insufficient fat to balance them out can result in sanding, where the milk sugars themselves crystallize and cause a gritty texture.[9] The milk solids can come from liquid dairy in the ice cream base (e.g. milk, cream) or can be added in the form of nonfat milk powder.[4][9]
Stabilizers
[edit | edit source]A variety of stabilizers may be used in ice cream-making, especially on a commercial scale.[3][8] Technically, sugar, eggs, cold temperatures, etc. as described above are all stabilizers in their own right,[3][8] but a number of specific additives are also available. These stabilizers have diverse roles, ranging from emulsifiers to water binders and viscosity raisers.[3][7][8] If an ice cream does not become liquid after melting, this is a sign that it contains a high proportion of stabilizing additives.[5] If an ice cream separates after melting, this indicates excessive use of stabilizers.[10]
| Stabilizer | Type | Description | Role |
|---|---|---|---|
| Polysorbate 80[3] | Carbohydrate + fatty acid | Emulsifies; maintains scoopability | |
| Glycerol monostearate (GMS)[11] | White powder, slightly sweet | Emulsifies; prevents fat globule coalescing | |
| Alginate[3] | Carbohydrate | Extracted from algae | Water-binding and thickening; retards ice crystal formation |
| Carrageenan[3] | Carbohydrate | Extracted from algae | Substitute for alginate |
| Whey[3] | Protein | Emulsifies; coats fat globules | |
| Gelatin | Protein | Water-binding and thickening; retards ice crystal formation | |
| Pectin | Carbohydrate | Water-binding and thickening; retards ice crystal formation |
Flavoring
[edit | edit source]Flavorings for churned desserts come from a wide range of sources. Be aware that cold and overrun reduce the overall perception of flavor, so an unfrozen ice cream base may taste stronger than you think it should.[8]
| Type | Examples | Method of use | Considerations |
|---|---|---|---|
| Fruit purée[7] | Raspberry purée, mango purée, strawberry purée | Blend into cooled base before freezing. | For regular purées, replace all of the milk with fruit purée; for strong or concentrated purées, replace half the milk; pulpy fruits benefit from homogenization. |
| Whole spices[7] | Coffee, vanilla bean, tea, cinnamon stick | Infused into milk and cream while heating, then strained out before freezing. | |
| Alcohol[5][8] | Liqueurs, brandy, whiskey | Blend into cooled base before freezing. | Alcohol lowers the freezing point and in excess will prevent the ice cream from freezing at all. |
| Concentrated fatty pastes[7] | Melted chocolate, praline paste, nut butter | Blend into hot base before cooling. | |
| Extracts | Peppermint extract, vanilla extract | Mix into cooled base before freezing. |
Add-ins
[edit | edit source]A huge variety of add-ins can be incorporated into ice creams, from candy to fruit (fresh or dried), nuts, chocolate, ganache, dessert sauces, pretzels, cookies, and more.[7][8][9] Unlike flavorings, they should retain their individual identities within the ice cream; as a result, in order to prevent them from disintegrating and/or disappearing into the base, these add-ins are typically gently folded into the base after it is churned but before it is hardened.[7][8][9]
Fruits and nuts benefit from being conditioned in a hot sugar syrup or alcohol before addition to the ice cream.[8][9] This lowers their freezing point and prevents excessive hardening once the ice cream is frozen.[7][8][9]
Production
[edit | edit source]Base preparation
[edit | edit source]The first step in ice cream making, whether large- or small-scale, is to prepare the base. This can be as simple as just stirring together the ingredients over heat to dissolve the sugar and denature whey proteins,[2][4][7] but more elaborate preparations may require the base to be cooked into a custard with eggs. Large-scale manufacturers may formally pasteurize the mixture.[2]
Aging
[edit | edit source]After the base is prepared and cooled, it benefits from a period of so-called "aging".[7][9] During this time, the base is allowed to rest for several hours in a refrigerator. This gives proteins in the base time to swell and bind water, which will ultimately reduce the formation of ice crystals during freezing and improve the final texture.[5][7][9][8] This aging period also properly cools the base, which speeds the freezing process.[2][8] The minimum here is 4 hours, with 12 hours being preferable and 24 hours being excellent.[7][8][9]
Churning
[edit | edit source]The process of churning the ice cream base requires two components: freezing and mixing. The former, of course, solidifies the mixture, while the latter disrupts the formation of large ice crystals and incorporates air.[2][5][8]
Before the advent and widespread availability of mechanical freezers, ice cream was made in a bath containing salt and ice. Pure ice on its own does not absorb enough heat from the ice cream base to make the base freeze. However, adding salt to the ice lowers its freezing point;[2] the ice is forced to melt, which causes it to absorb more heat from the ice cream base, thus allowing the base to freeze.[3][13] Nowadays, ice cream machines typically use a specialized canister that can be pre-chilled to the required temperature or use an internal compressor-based chiller.[8] See the ice cream machine page for more details. The more quickly the freezing takes place, the smaller the ice crystals and the better the texture.[1][2][5]
To mix the ice cream, a constantly rotating paddle or canister—depending on the type of machine—is used to agitate it.[3] The base touching the cold canister wall begins to freeze and is quickly distributed throughout the rest of the liquid, allowing more base to come into contact with the wall.[2][6] Typically, the base is churned until it is the texture of soft-serve (a very thick paste that is difficult to mix).[2][7] Then, if possible, the cooling mechanism is turned off, and the mixture is allowed to churn for a couple more minutes to prevent excess sticking to the walls.[9]
A particularly interesting and unconventional way of producing ice cream is by way of liquid nitrogen. Because of how cold liquid nitrogen is, it produces very small ice crystals very quickly, resulting in very finely textured ice cream that feels particularly cold. Tiny pearls of ice cream can be made by dripping the base into the liquid nitrogen,[1] and a more traditional ice cream can be made by very gradually stirring liquid nitrogen into the liquid base using an electrical mixer.[6]
Hardening
[edit | edit source]After churning, the ice cream must be packed into containers and transferred to a freezer for the final chilling and hardening. As during the churning stage, it's important that this freezing take place as rapidly as possible to discourage the formation of large ice crystals and the resulting coarse texture.[2][3][4][5] This should take place in a very cold freezer (well below 0°F / –18°C),[5][8][9][14] and packing the ice cream into small containers can also help increase the surface area and speed the freezing process.[2]
Varieties
[edit | edit source]Several varieties of ice cream and other churned dessert are made.
Philadelphia-style
[edit | edit source]This variety—also called "standard" or "New York" style[2][3]—is very simple, requiring minimal ingredients and heating. Typically, the base consists simply of milk, cream, and sugar, with flavoring components mixed in as desired.[2][4][7] It is considered delicate in flavor,[2] with the quality and flavor of the dairy highlighted. Because they do not contain eggs, they can sometimes benefit from other stabilizers.[9]
French-style or frozen custard
[edit | edit source]A slightly more complex ice cream, termed French-style or frozen custard, uses whole eggs or yolks to make an anglaise-style custard base with the milk, cream, and sugar.[2][3][5] The egg provides additional flavor and contributes to a smooth texture.[5][7][10][14] This variety can be flavored much like Philadelphia-style ice cream.[5][9]
Gelato
[edit | edit source]Strictly speaking, gelato is simply the Italian word for ice cream.[7] However, the term in English usually refers to an ice cream with particular properties, though these exact properties are debated.[7] Some say that gelato does not contain eggs,[1][15] while others argue that it does;[2][7][9][16] some say it is low in fat/cream, while others say it is high in these.[2][3][5] Generally, there is consensus that gelato has less overrun than other styles of ice cream,[2][3][8][16] lending it a dense texture.[4][5][7] Gelato may be served at a warmer temperature than other ice creams.[15][16]
Frozen yogurt
[edit | edit source]Frozen yogurt is ice cream that includes yogurt as a significant part of the base.[5] It comes in a variety of flavors.[5]
Sorbet
[edit | edit source]Sorbet is a churned dessert typically made from fruit juice or purée with a high sugar concentration.[7] Other flavorful liquids like tea, wine, or infusions may also be used.[7][8] As they do not contain any dairy,[1][3][5][7] sorbets benefit from the addition of a stabilizer/aerator like egg white or a commercial stabilizer (e.g. gelatin, gums) to improve the texture.[1][7][8][12] For the same reasons, sorbet also requires a higher proportion of sugar.[5] Replacing some of the granulated sugar with glucose syrup can help reduce crystallization and improve the texture as well.[7][8] Juices or other liquids low to no pulp are more vulnerable to separation than fruit purées, and adding egg whites or a commercial stabilizer can help prevent this.[7]
Sherbet
[edit | edit source]Like sorbet, sherbet is often fruit-flavored, but sherbet can contain a small amount of dairy products like milk or cream.[5][7][10][15] This gives it slightly richer flavor and texture than sorbet.[8] Sherbet may also contain egg white for the textural properties.[10]
Soft serve
[edit | edit source]Soft serve ice cream is churned to-order using a specialized machine that extrudes the ice cream with a nozzle.[14][15] It does not undergo hardening and is very soft as a result.[5][14][15] The precise components of the base can vary, with the texture being the primary characteristic. Because it is served at a relatively high temperature, additional stabilizers may be needed.[14] This variety is rarely commercially available in supermarkets, instead being sold by specialized vendors.
Selection and storage
[edit | edit source]The hallmarks of a high quality ice cream are a balanced flavor and texture. As churned desserts, they should be smooth, with no large ice or other crystals.[8] The texture should be reasonably dense, firm, and almost chewy.[2] Often, lower-quality ice creams weigh less than higher-quality ones at the same volume due to the higher amount of overrun.[2][3] Higher-quality ice creams may also contain a greater proportion of ingredients like cream and egg yolk and fewer commercial stabilizers and texturizers as a result.[2] However, the kind of ice cream you buy does of course come down to personal preference.
Ice cream must be stored in a consistently cold freezer to preserve its smooth frozen texture.[2] Well below 0°F/–18°C is ideal.[2][4][5] Freeze-thaw cycles or simply storing at a too-high temperature will cause the ice crystals to melt and reform into bigger crystals[2][4][5]—this is one reason that older ice cream experiences a decrease in textural quality and becomes grainy.[3][4][6] Ice cream should also be stored in an airtight container to prevent oxidation and the absorption of undesirable odors from the freezer environment.[4]
Techniques
[edit | edit source]Tempering
[edit | edit source]While ice cream should be stored well below 0°F/–18°C, this isn't actually the best temperature for serving it. If possible, it's best to temper the ice cream by keeping it at 6 to 15°F (–15 to –9°C) for several hours.[2][5][8] This makes the ice cream a little easier to scoop and allows for more perception of flavor.[2][5][8][9]
Molding and shaping
[edit | edit source]Because it starts out fluid and freezes solid, ice cream is particularly amenable to molding and shaping. After churning, fill your desired mold with the base, then allow it to undergo its final hardening. For very simple forms, you can use a bowl or cake pan; for more complex shapes, you can use specialty molds for baking and pastry.[7]
In restaurants, ice cream may be shaped into a quenelle for serving.[8] When scooping, it's generally best to avoid packing; rather, slice the scoop across the ice cream to roll it into a ball.[5]
Recipe development
[edit | edit source]The basic recipe for ice cream is very simple, consisting of milk, cream, sugar, and salt,[3] which allows a fair amount of room for experimentation and recipe development.[1][7] The key here is to keep all the components in balance with each other so you retain the correct texture.[1][2] Whenever creating a new recipe, make and test freeze a small batch first.[5]
Generally, ice cream formulations try to aim for about 60% water, 15–26% sugar, 7–20% milk fat, 4–8% protein, and 40% total solids (i.e. fat, sweetener, and nonfat milk solids).[1][2][4][9] Fruit sorbets and sherbets should have a sugar concentration of 30–32.5° Brix or 16–18° Baumé.[5][7][8] Sorbets based on alcohols, teas, or other infusions should have a concentration of 13–17° Baumé).[8] If desired, try adding egg whites at 30 g per 1.92 L sorbet base.[7] If adding glucose syrup to a sorbet, substitute it in for 10% of the sugar.[7] When adding significant amounts of flavoring (e.g. chocolate, nut butter, fruit purée), consider how this will affect the overall component proportions of the base, and adjust accordingly.
If adding whole fruit to ice cream, temper it with sugar by bringing to a boil in a heavy sugar syrup and letting it rest until cooled.[7] For harder fruits, make sure to leave the fruit in the hot (160–180°F/71–82°C) for 15 minutes.[7]
Troubleshooting
[edit | edit source]| Problem | Potential cause(s) | Try... |
|---|---|---|
| Sorbet is grainy | Base contains too little little sugar | Melt, add sugar syrup, and re-churn[8] |
| Ice cream is too hard | Base contains too little antifreeze | Increase antifreeze agents like sugar and alcohol. |
| Ice cream has too little overrun | Fill the churning canister less | |
| Add eggs to the base | ||
| Ice cream is too soft | Base contains too much antifreeze | Reduce antifreeze agents like sugar and alcohol. |
| Ice cream is grainy | Base contains too much milk solids | |
| Base was frozen too slowly | Churn in a very cold canister and harden in a very cold freezer. | |
| Ice cream was freeze-thawed | Pack ice cream in smaller containers to reduce thawing | |
| Ensure your freezer has a stable temperature | ||
| Base was insufficiently agitated |
Use
[edit | edit source]Ice creams may be served simply on their own or as part of a larger dessert. When ice cream is the focus, it is often scooped into a bowl or onto an ice cream cone[8]—fancy terms for the former include "coupe" and "sundae", especially when served with toppings.[5][8] Such toppings range from syrups and sauces to cookies, candies, sprinkles, fruits, nuts, and more.[9] In the United States, an ice cream parfait refers to alternating layers of ice cream and toppings in a tall, narrow, glass.[5][8] A baked Alaska tops molded ice cream with soft toasted meringue,[5][8] and other molded desserts like ice cream cakes layer ice cream base with sponge cake.[7] Vanilla ice cream is often served with a variety of other desserts, such as pies, brownies, and various warm desserts.
Various regional variations of ice cream exist. For example, Western Asian ice cream may contain salep and/or mastic, which provides a stretchy texture.[17] In Southeast Asia, ube, coconut, corn, and cheese all flavor ice cream.[17]
Gallery
[edit | edit source]-
Gelato -
A cup of soft serve frozen yogurt -
A scoop of frozen yogurt -
Soft serve ice cream -
Cup of sorbet
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Recipes
[edit | edit source]Recipes for ice cream
[edit | edit source]Recipes using ice cream
[edit | edit source]References
[edit | edit source]- ↑ a b c d e f g h i j k l m n o p q r s t u v w x Vega, Cesar; Ubbink, Job; Linden, Erik van der (2013-08-13). The Kitchen as Laboratory: Reflections on the Science of Food and Cooking. Columbia University Press. ISBN 978-0-231-15345-4.
- ↑ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah McGee, Harold (2007-03-20). On Food and Cooking: The Science and Lore of the Kitchen. Simon and Schuster. ISBN 978-1-4165-5637-4.
- ↑ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab Provost, Joseph J.; Colabroy, Keri L.; Kelly, Brenda S.; Wallert, Mark A. (2016-05-02). The Science of Cooking: Understanding the Biology and Chemistry Behind Food and Cooking. John Wiley & Sons. ISBN 978-1-118-67420-8.
- ↑ a b c d e f g h i j k l m n o p Gibson, Mark (2018-01-04). Food Science and the Culinary Arts. Academic Press. ISBN 978-0-12-811817-7.
- ↑ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq Gisslen, Wayne (2016-09-21). Professional Baking. John Wiley & Sons. ISBN 978-1-119-14844-9.
- ↑ a b c d Field, Simon Quellen (2011-11-01). Culinary Reactions: The Everyday Chemistry of Cooking. Chicago Review Press. ISBN 978-1-56976-960-7.
- ↑ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as The Culinary Institute of America (CIA) (2015-02-25). Baking and Pastry: Mastering the Art and Craft. John Wiley & Sons. ISBN 978-0-470-92865-3.
- ↑ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at Labensky, Sarah; Martel, Priscilla; Damme, Eddy Van (2015-01-06). On Baking: A Textbook of Baking and Pastry Fundamentals, Updated Edition. Pearson Education. ISBN 978-0-13-388675-7.
- ↑ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai Friberg, Bo (2016-09-13). The Professional Pastry Chef: Fundamentals of Baking and Pastry. Wiley. ISBN 978-0-470-46629-2.
- ↑ a b c d e The Culinary Institute of America (CIA) (2011-09-13). The Professional Chef. John Wiley & Sons. ISBN 978-0-470-42135-2.
- ↑ a b c d The Chefs of Le Cordon Bleu (2011-12-02). Le Cordon Bleu Patisserie and Baking Foundations. Cengage Learning. ISBN 978-1-4390-5713-1.
- ↑ a b c d e Figoni, Paula (2010-11-09). How Baking Works: Exploring the Fundamentals of Baking Science. John Wiley & Sons. ISBN 978-0-470-39267-6.
- ↑ Helmenstine, Anne (2020-07-19). "Why Salt Makes Ice Colder - How Cold Ice Gets". Science Notes and Projects. Retrieved 2024-11-25.
- ↑ a b c d e "What Is Soft-Serve Ice Cream? | Cook's Illustrated". www.americastestkitchen.com. Retrieved 2024-11-22.
- ↑ a b c d e Goldstein, Darra (2015-01-01). The Oxford Companion to Sugar and Sweets. Oxford University Press. doi:10.1093/acref/9780199313396.001.0001. ISBN 978-0-19-931339-6.
- ↑ a b c Kipfer, Barbara Ann (2012-04-11). The Culinarian: A Kitchen Desk Reference. Houghton Mifflin Harcourt. ISBN 978-0-544-18603-3.
- ↑ a b Davidson, Alan (2014-01-01). Jaine, Tom (ed.). The Oxford Companion to Food. Oxford University Press. doi:10.1093/acref/9780199677337.001.0001. ISBN 978-0-19-967733-7.