4 ms·

It's (historically) even simpler to make lactose-free milk by making cheese or certain types of yogurt.

by folli 5y ago

cheese_goddess 5y ago
Cheese is not necessarily lactose-free. It depends on the type of cheese. tl;dr, cheese has less lactose than milk but not necessarily 0%. As a rule-of-thumb, softer, crumblier, fresher, tangier cheeses, and yogurt, should be expected to have less lactose than harder, longer-aged firm and elastic and sweeter cheeses, but again not necessarily 0%. Now for the long version. Fresh milk has a sweet taste thanks to the lactose it contains. Lactose is a complex sugar composed of two simple sugars, glucose and galactose. When cheese or yogurt are made, lactic acid bacteria (LAB) ferment the lactose in milk and produce lactic acid (hence their name). Lactic acid lowers the pH of the milk and so the cheese or yogurt ends up more acidic, therefore tasting tangier, than the milk used to make it. Lower pH also affects the texture of the cheese: as a rule, more acidic cheeses are softer and crumblier whereas less acidic cheeses are firmer and with a more elastic texture. The cheesemaking process controls the extent to which fermentation is allowed to continue and acidity to develop. Some cheeses, like cheddar, are salted to stop (rather, slow down) the activity of LAB and arrest the development of acidity. Others, like fresh goat's cheeses, are left to ferment all the way. Yogurt is allowed to ferment all the way also. LAB activity generally stops at a pH of 4.6, at which point most LAB become inactive, but that doesn't mean that all of the lactose is consumed when that pH is reached. It depends on how much lactose was in the milk to begin with and how fast the fermentation advanced during the making of the cheese. In making Italian Cacciota cheese, a warm-room technique is used to bring the curd to a temperature near the optimum of the LAB culture, so that all the lactose is consumed quickly and the cheese reaches its target pH of 5.2 (so higher than 4.6), in a relatively short time (hours rather than days). "Washed curd" cheeses like Gouda, have a step in their make where whey is replaced with water, to "wash out" the lactose and stop the fermentation, so that the cheese retains its milky sweeteness. Acidity can also decrease (pH increase) during ripening. Some bloomy rind type cheeses like camambert start out quite acidic, with a low pH under 5.0 but their pH increases while they age because the molds and yeasts on their rind (that give them their characteristic white coats) consume lactic acid and release ammonia (which, being basic, raises the pH back up). So it's not always easy to know how much lactose is in cheese and yogurt and it's not even an absolute rule that more acidic taste means more complete fermentation and so less lactose. Certainly, cheese can still have lactose. Less than milk, but not 0%. The safest bet is to look at the ingredients listed on the packaging, which sometimes (but not always) will list the amount of lactose.

It's (historically) even simpler to make lactose-free milk by making cheese or certain types of yogurt.

by folli 5y ago

It's (historically) even simpler to make lactose-free milk by making cheese or certain types of yogurt.

Cheese is not necessarily lactose-free. It depends on the type of cheese. tl;dr, cheese has less lactose than milk but not necessarily 0%. As a rule-of-thumb, softer, crumblier, fresher, tangier cheeses, and yogurt, should be expected to have less lactose than harder, longer-aged firm and elastic and sweeter cheeses, but again not necessarily 0%. Now for the long version. Fresh milk has a sweet taste thanks to the lactose it contains. Lactose is a complex sugar composed of two simple sugars, glucose and galactose. When cheese or yogurt are made, lactic acid bacteria (LAB) ferment the lactose in milk and produce lactic acid (hence their name). Lactic acid lowers the pH of the milk and so the cheese or yogurt ends up more acidic, therefore tasting tangier, than the milk used to make it. Lower pH also affects the texture of the cheese: as a rule, more acidic cheeses are softer and crumblier whereas less acidic cheeses are firmer and with a more elastic texture. The cheesemaking process controls the extent to which fermentation is allowed to continue and acidity to develop. Some cheeses, like cheddar, are salted to stop (rather, slow down) the activity of LAB and arrest the development of acidity. Others, like fresh goat's cheeses, are left to ferment all the way. Yogurt is allowed to ferment all the way also. LAB activity generally stops at a pH of 4.6, at which point most LAB become inactive, but that doesn't mean that all of the lactose is consumed when that pH is reached. It depends on how much lactose was in the milk to begin with and how fast the fermentation advanced during the making of the cheese. In making Italian Cacciota cheese, a warm-room technique is used to bring the curd to a temperature near the optimum of the LAB culture, so that all the lactose is consumed quickly and the cheese reaches its target pH of 5.2 (so higher than 4.6), in a relatively short time (hours rather than days). "Washed curd" cheeses like Gouda, have a step in their make where whey is replaced with water, to "wash out" the lactose and stop the fermentation, so that the cheese retains its milky sweeteness. Acidity can also decrease (pH increase) during ripening. Some bloomy rind type cheeses like camambert start out quite acidic, with a low pH under 5.0 but their pH increases while they age because the molds and yeasts on their rind (that give them their characteristic white coats) consume lactic acid and release ammonia (which, being basic, raises the pH back up). So it's not always easy to know how much lactose is in cheese and yogurt and it's not even an absolute rule that more acidic taste means more complete fermentation and so less lactose. Certainly, cheese can still have lactose. Less than milk, but not 0%. The safest bet is to look at the ingredients listed on the packaging, which sometimes (but not always) will list the amount of lactose.