🧫 Lactic acid bacteria
Also known as: LAB, lactobacilli
Lactobacilli and streptococci that ferment lactose.
Lactic acid bacteria are a large group of harmless microbes. They got their name because they turn sugar into lactic acid. The best known are lactobacilli, lactococci and some streptococci. They live in nature, on plants, and in the gut of humans and animals.
For dairy products, these bacteria do the main work. They ferment lactose, the milk sugar, turning it into lactic acid. This makes milk sour and thick: that is how yogurt, kefir, cottage cheese, sour cream and cheese are made. The acidic environment stops harmful germs from growing, so fermented foods keep longer. Some species make almost nothing but lactic acid; others also make carbon dioxide and a little alcohol.
In the USA and other countries these bacteria are considered safe to eat: people have eaten them for thousands of years. Many probiotics, supplements with live microbes, also come from this group. But any health benefit depends on the specific strain, that is, the particular variety of bacterium. So a general “good for your gut” promise on the pack should be read with care.
Wine
Wine lactic acid bacteria are bacteria that turn malic acid in wine into lactic acid. The main species is Oenococcus oeni. The process is called malolactic fermentation.
Malic acid is sharp, like that of green apples, while lactic acid is softer, like that in milk and yoghurt. After the fermentation the wine becomes softer and less acidic. New aromas appear as a by-product, such as a note of butter and cream. This is why the fermentation is common in red wines and in some whites, such as Chardonnay. In fresh, light whites it is sometimes prevented to keep the acidity.
The bacteria begin work after the alcoholic fermentation, at a warm temperature. Winemakers can add a chosen culture or wait for the bacteria to arrive on their own. If the process happens in the bottle, the wine may turn cloudy and fizz, so it is monitored.
They are relatives of the bacteria that make kefir, yoghurt and sauerkraut, all lactic acid bacteria. They matter for wine because they make the taste softer and more stable.
What it includes
How it connects to milk
🧫 Lactic acid bacteria → affects → ❤️ Digestion ← benefit ← 🥛 Goat's milk → type of → 🥛 Milk
Links
- Needed for
- 🧫 Starter culture, 🫒 Spanish-style green olives
- Who works with it
- 🍷 Malolactic fermentation
- What they produce
- 🧪 Lactic acid
- What it affects
- ❤️ Digestion, 🛡️ Immunity
- Part of
- 🍷 Winemaking
- Wine and milk
- 🍷 Malolactic fermentation
Frequently asked questions
What do lactic acid bacteria do?
They feed on sugars, including lactose, and give off lactic acid. This makes milk sour and turns it into yogurt, kefir or cottage cheese.
Are lactic acid bacteria and probiotics the same thing?
Not quite. Many probiotics are lactic acid bacteria, but only a strain with a proven benefit at a set dose is called a probiotic.
Are there live bacteria in kefir and yogurt?
Yes, if the product was not heated after fermenting. The pack usually says “live cultures”.
Recipes
History
What to read next
- 🧫 Starter culture — A bacterial culture for fermented dairy products.
- 🫒 Spanish-style green olives — Green olives treated with lye and fermented in brine by lactic acid bacteria.
- ❤️ Digestion — How easily milk is digested depends on fat globule size, casein type and lactose.
- 🛡️ Immunity — Antibodies in colostrum and breast milk.