What is a bloomy rind? Coagulation? Oxidation? There’s a lot of specialist vocab in the dairy world which we might not be familiar with, but look no further! We’ve compiled this A-Z of technical terms you should know if you’re serious about cheese education. Acidity The chemical property of milk due to the presence of acids and acid groups. Acidity tends to rise naturally after fermentation, the formation of lactic acid from lactose, and lipolysis, or the liberation of fatty acids. It plays a fundamental role in the coagulation, or curdling, of milk. Bloomy rind A bloomy, or moldy, rind is caused by surface microflora (Mucor and Penicillium) that generate a grey-white mold. Characteristic of soft-ripened cheeses such as Taleggio and Camembert. Butter The term “butter” is legally defined in Italy as “the product obtained by the mechanical processing of cream taken from cow’s milk, from cow’s milk whey, or from a mixture of these products”. The mechanical operation involved is churning. This entails the agitation of the cream to encourage the rupture of the external membrane of fat and separate the watery component (buttermilk). The removal of fatty elements in liquid form incorporates all the components of the cream and gives butter its special structure. Casein The most plentiful of the proteins in milk, accounting for about 80% of the total. It is made up of various fractions (alpha, beta and kappa) that coagulate to form curd when attacked by enzymes or acidity (see Curd). Caves Sheltered, stable, natural environments where some cheeses are matured, especially soft and blue cheeses. Known as grotte in Italian. Cool and damp, their temperature and humidity are regulated by cold, moist air entering through cracks in the rock. The caves of Valsassina, for taleggio, and the so-called fleurines for maturing roquefort, are two examples. Cheese cellar A suitable place for maturing cheeses, with optimal light, temperature and humidity conditions for promoting the physiological processes involved in ageing. Coagulation Coagulation, or curdling, is the fundamental transformation in cheesemaking. A number of factors, including acidity, temperature, mineral salts in the milk and inoculation with rennet, cause the precipitation of the casein to form the curd and separate it from the whey. When the precipitation of casein is caused by acidity, this is known as acid coagulation (for cheeses such as Robiola di Roccaverano, quark, mascarpone and others). Rennet-based coagulation involves inoculation with rennet and is used for the majority of cheeses. Colostrum Milk secreted by the mammary gland in the first days after parturition. It has a different chemical composition from ordinary milk. Cooked and semi-cooked cheese A category of cheeses characterized by cooking of the just-cut curd to promote separation from the whey, render the curd more elastic and encourage clotting. Cooking temperatures range from 44- 45°C (semi-cooking, as for fontina, asiago, bitto and others) to 54-55°C (cooking, as for grana padano, parmigiano reggiano, emmental and so on). Cream An important milk product that rises to the top of standing milk, or is separated by skimming in a centrifuge. It is used mainly for making butter but has many other applications in the confectionery industry. Cream contains 25-40% fat but the proportions of its other constituents are almost identical to those of the original milk. Curd The clotted portion of coagulated milk, which has transformed into a gel after inoculation with rennet, or the curdling of the milk. Curd is essentially casein in gelatinous phase that has been separated from the whey. This separation is the first stage in cheesemaking. Curing The final stage in cheesemaking and the one that determines the final condition of the cheese (see Maturing). Curing is carried out in special cheese cellars or caves, or in temperature-controlled cells. It may last for only a few days, in the case of soft cheeses, or continue for several years for some hard cheeses. During this stage, the cheeses must be regularly turned over and cleaned. Cutting the curd The mechanical operation of breaking the curd in order to promote the separation and expulsion of the whey. Initially, the soft curd is cut into large pieces. The operation is then repeated until the granules are of the dimensions required. The lumps for fresh, soft cheeses are walnut or hazelnut-sized, sweetcorn-sized for uncooked pressed cheeses and the size of a grain of rice for cooked hard cheeses. Enzyme A complex organic substance that promotes certain chemical reactions. Milk contains about sixty different enzymes, some of which are extremely important for cheesemaking. The chymosin, pepsin and lipases contained in rennet (see Rennet) are also enzymes. Eyes The holes that form in the body of the cheese after acid fermentation, which produces gas, especially carbon dioxide. Eyes are usually small and uniform in size, although there are some exceptions, such as Emmental. In this case, the eyes are large and distributed extensively as a result of the action of propionibacterium, which transform lactic acid into propionic acid and carbon dioxide. Fat The principal component of milk, where it is found in the form of suspended globules enclosed in a phospholipid and vitamin-rich membrane. The proportion of fat in milk varies from one dairy species to another. It has significant nutritional value as a source of energy and vitamins. Fat is a fundamental component of cheese, contributing to its aroma and flavor. Cheeses are classified according to the fat content in the dry matter, expressed as a percentage – low-fat (less than 20%), semi-fat (20-42%) and fat (more than 42%). Hard cheese Cheeses whose water content is less than 40%. Uncooked pressed cheeses and stretched curd cheeses, as well as cooked and semicooked cheeses, fall into this category. Heat treatment The application of heat to raw milk for at least fifteen seconds at a temperature of 57-68°C. Also known as thermization. After heat treatment, the milk should react positively to a phosphatase (enzyme) test. The aim of heat treatment is to reduce the native flora of the milk without altering excessively its cheesemaking properties. Hoops Special cheese molds used to hold the curd after cooking. The curd may be left to drain (soft cheeses) or pressed (hard cheeses). Hoops may be made of beechwood, metal or synthetic resin. The hoops give the side of the cheese its shape and can be used to print marks of origin. Inner rind The superficial layer of the body, just under the rind, with a more intense color and more marked taste because it is most affected by the chemical process of oxidization. In soft cheeses, proteolysis occurs on the inner rind because of the surface microflora. Lactose The sugar found in milk, in which it is the most easily assimilated source of energy. In chemical terms, lactose is the union of one molecule of glucose with one of galactose, and is not common in nature. Its fermentation into lactic acid through the action of lactic flora is important because this influences the taste profile of the cheese. Lipolysis The breakdown of fats promoted by the presence of specific enzymes (lipase). Lipolysis is significant in the maturing process of some cheeses characterized by strong hydrolysis, or breakdown by water, of the fat. In pecorino and provolone, maturing is promoted by rennet paste-derived lipase, and in gorgonzola by lipase from mold. Maturing The overall result of various chemical and physical processes involving the curd. They determine the texture of the body, the external appearance of the cheese, and above all its final aroma and taste. The temperature and humidity of maturing rooms must be regulated with extreme precision. Milk By international convention, milk is defined as: “The whole product obtained from the complete, uninterrupted milking of a healthy, well-fed, rested, female dairy animal. The milk should be collected carefully and hygienically, and should not contain colostrum. The unqualified indication, ‘milk’, indicates cow’s milk. Cleaning of material and utensils should be carried out in such a way that the composition of the milk cannot be modified in any way”. The average composition of cow’s milk is as follows: water 87-88%, fat 3.4-4.4%, proteins 3-3.5%, lactose 4.7-5.2%, mineral salts 0.8-1%. The milk of other ruminants is also suitable for transformation into cheese. Sheep’s milk, goat’s milk, both highly prized, and buffalo’s milk are common alternatives. Milk enzymes Important micro-organisms (bacteria) for cheesemaking because they promote acidity and the precipitation of milk protein into a solid curd. They are mainly responsible for the taste profile of the cheese as they act on lactose and other major components of milk during fermentation. Bacteria, including milk enzymes, are in part removed by cooking and most are eliminated during pasteurization. It is necessary to inoculate pasteurized milk with a starter culture in order to turn it into cheese (see Starter culture). Molds Micro-organisms belonging to the Eomycota division of the Mycota kingdom, of the genera Aspergillus, Mucor, and Penicillium, which live as saprophytes on organic substances and form an efflorescence with their fruiting bodies. The sometimes-powdery efflorescence may be white, grey, greenish or even black. Mountain pasture A mountain region used in summer for pasturing dairy herds, where the fodder plants contain flavor-enhancing compounds that give the milk special characteristics. The Italian term alpeggio implies the presence of a milking dairy. But there are many other names for mountain pastures, which vary from region to region. Two of the more frequently encountered are malga and alpe. Outer rind A superficial layer that forms on the cheese after salting, ripening and maturing. In soft cheeses, the surface microflora makes a crucial contribution to the texture and taste profile of the final product. In other types, the outer rind has the main function of protecting the cheese and exchanging gas and water vapor with the surrounding environment. The rind may be washed, oiled or paraffin-waxed to prevent the growth of mold and the red coloring due to the presence of oospores. In certain cases, such as pressed cheeses, the rind is removed and replaced with a protective wrapping of polyvinyl acetate. Rinds may be smooth, rough, rush mat-patterned, lustrous, thin, yellow, ivory, brownish, pock-marked, cracked and so on. Oxidation A chemical process that affects cheeses after prolonged exposure to air. Oxidation produces visible modification of the body color as well as alterations of the cheese’s nose and palate as fatty matter becomes rancid. Pasteurization The application of heat to raw milk for at least fifteen seconds at a temperature of at least 71.7°C. After pasteurization, the milk should react negatively to the phosphatase (enzyme) test. The aim of pasteurization is to destroy all pathogenic germs and ensure the healthfulness of the milk while enhancing its low-temperature storage potential. Since 2017, no pasteurized cheeses are allowed to be sold at Cheese, with very few exceptions (e.g. Gorgonzola DOP). See the Natural is Possible section. Penicillium A genus of fungi that grows inside or on the surface of cheeses. Penicillium roqueforti is the main agent responsible for internal veining in roquefort, gorgonzola and similar blue cheeses. Penicillium camemberti acts on bloomy rind cheeses, such as camembert or brie. Stretched curd A cheesemaking technique involving immersion of the curd in hot, acid whey for several hours to remove minerals from the body and render it elastic. The curd is then kneaded and stretched in warm water at 70-90°C until it acquires the desired shape. Cheeses of this type include mozzarella, provolone, caciocavallo, ragusano and others. Pressing A technique used mainly for uncooked hard cheeses. Pressure is applied for a period ranging from one to twenty-four hours to expel whey before a sturdy outer rind forms. Proteins Proteins are the fundamental components of milk whose functional properties determine the basic cheesemaking technique. They are nitrogenous compounds and may be classified into two large groups: caseins and whey proteins. Caseins are found in suspension in milk in the form of micelles. They precipitate under the effect of rennet or acidity. Proteolysis A fundamental process in the maturing of cheeses, involving the breakdown of complex casein molecules into simpler nitrogenous compounds (amino acids). Proteolysis is encouraged by specific proteolytic enzymes. Raw milk Milk that has not been heat-treated, used for cheesemaking. Raw milk still has the original microflora it acquired from its environment. The microflora contribute to the taste profile of the final cheese. Rennet An extract of animal origin containing proteolytic enzymes (chymosin and pepsin) that coagulate casein. Generally obtained from the abomasum, or fourth stomach, of unweaned ruminants (calves, kids or lambs). Some rennets also contain lipases, enzymes that can catalyze the hydrolysis of fats and contribute to the sensory profile of the cheese. Commercial rennet is available in a number of forms, and may be used as a liquid or in powder, pellets or paste. Other coagulants may be of vegetable or fungal origin. Ricotta According to Italian law, ricotta is not a real cheese because it is not obtained from the coagulation of casein in milk. It comes instead from the coagulation of the proteins in whey at high temperature (80-90°C), a by-product of the processing of cow’s, sheep’s or goat’s milk. From a nutritional point of view, ricotta is low in fat and rich in complete proteins. Ripening The stage of cheesemaking that comprises storing the cheese in a warm (24-28°C), humid room for a few hours in order to complete the fermentation process and synaeresis (for gorgonzola and taleggio, etc.). Rising of the cream A physiological process that takes place in standing milk as the fatty emulsion rises to the surface because of its relative weight. This phenomenon is exploited in the preparation of partially-skimmed milk to be used for semi-fat cheeses, such as Grana Padano and Parmigiano Reggiano. Salting The final treatment applied to cheese before maturation. Salt is a preserving agent and an antiseptic that inhibits the growth of micro-organisms. It also has an osmotic effect as the cheese releases whey and absorbs salt. Salting may take the form of dry-salting, in which the salt is sprinkled onto, or rubbed into, the outer surface, immersion of the cheese in vats of brine for a period of time that varies depending on its weight, or by the addition of salt to the milk or curd. Skimming The process of removing part of the fat from the milk. Milk is skimmed naturally by the rising of the cream (see Rising of the cream). The process may be mechanized and accelerated with the aid of cream-separating centrifuges. Smoking The process of exposing a food product to the action of certain components in the smoke released by the combustion of various vegetable substances. Smoke is deposited on the food product through the absorption of steam, in which superficial and interstitial moisture acts as an absorption vehicle. Many cheeses are conserved using this technique. Soft cheese Cheeses whose water content is more than 40%. This category includes fresh cheeses for immediate consumption (mozzarella, robiola, quartirolo and so on) and medium mature cheeses (such as gorgonzola and taleggio). Starter culture The addition to the milk to be transformed into cheese of selected starter cultures of specific bacteria which promote the fermentation of lactose and other components. The main cultures used are milk and whey. Starter cultures are therefore milk or whey-inoculated (natural growth of bacteria), or milk or whey-fermented (selected bacterial growth). Such cultures may be produced in-house by the cheesemaker from their own milk or whey, thus conserving the natural biodiversity of microbial flora in the place of production, or bought commercially from companies which grow homogenous cultures in laboratories. Synaeresis The set of phenomena provoking the expulsion of whey from the curd. Synaeresis occurs more readily in rennet-based coagulation than in the acid-promoted process, since the curd is less contractile. Top and bottom The two plane surfaces on which cylindrical cheeses rest. The top and bottom surfaces of a cheese may be flat, as in grana and parmigiano, convex, such as asiago pressato, or concave, as in some canestrato (mat-drained) cheeses. The top or bottom sometimes carries the cheese’s mark of origin. Uncooked cheeses A category of cheeses made without cooking the curd after it is cut. Fresh cheeses and soft cheeses are all uncooked. Some hard or semi-hard cheeses, such as raschera and castelmagno from Italy, cheddar from the United Kingdom and edam from Holland, are pressed and uncooked. Veining The distinguishing feature of blue cheeses whose body is veined with blue or green mold. Also called “marbling”, veining is characteristic of some of Europe’s greatest cheeses, such as Italy’s gorgonzola, stilton from the United Kingdom and roquefort and other blue cheeses from France. The Italian word erborinatura derives from the Lombard dialect word erborin, meaning “parsley”, a reference to the color and structure of the body of such cheeses. The term used in French is persillé. Whey The liquid by-product of cheesemaking which contains lactose, whey proteins and mineral salts. Whey accounts for about 90% of the original milk. It is partially recycled in the cheese factory for the preparation of starter cultures and ricotta. Whey is also used in the confectionery industry as a powder or concentrate, and as an animal feed. Whey proteins Proteins that are not precipitated by rennet or acidity and that remain in the whey in solution. The major whey proteins are lactalbumins and lactoglobulins. These proteins may be recovered in the form of ricotta, or cottage cheese. Colostrum is also extremely rich in lactalbumins and lactoglobulins, and thus they are the first antibodies to be acquired by newborn animals and humans. Yield The proportion of milk transformed into cheese during cheesemaking. Yield is expressed as a percentage in kilograms of cheese obtained per 100 kilograms of milk used. A yield of 10% is reckoned to be average, but the figure may range from 15-20% for very fresh products, and as low as 7-8% for hard cheeses. This cheese dictionary is an extract from the book Italian Cheese: A guide to its discovery and appreciation (2011) published by Slow Food Editore.