Is yogurt halal?

Yogurt starts with milk

Milk is one of the pure blessings the Quran mentions by name. Allah reminds us that He brings it out of cattle, clean and pleasant to drink:

Yogurt is milk plus bacteria such as Lactobacillus and Streptococcus thermophilus. Those cultures are halal. Natural, Greek, Turkish and Icelandic-style plain yogurts are generally fine, whatever the brand.

Ingredients to watch for

• Gelatin: some low-fat, fruit, mousse-style and "thick and creamy" yogurts use gelatin as a thickener. It's often from pork or non-halal beef. If the label just says "gelatin" or "beef gelatin" with no halal mark, most Muslims skip it. See Can I still eat gummy bears as a Muslim?
• Carmine (E120, cochineal): a red coloring made from insects, used in strawberry and cherry yogurts. Scholars differ: the Maliki school and many others allow it, while some Shafi'i and Hanafi scholars avoid it.
• Liqueur flavors: rum-and-raisin or "Irish cream" desserts can contain real alcohol.
• Other additives: some E-numbers can be animal-derived. See Are E-numbers halal?

What about rennet or enzymes?

Yogurt doesn't normally use rennet; that's mainly a cheese issue. If you're also wondering about cheese, the rules on rennet are explained in Is cheese halal?

Fermentation and alcohol

Fermentation can create a tiny trace of alcohol in some yogurts and kefir. Scholars generally say this is not a problem, because it's far too small to intoxicate and is a natural part of the food, not something added. Homemade kefir left to ferment for a long time is different; if it becomes fizzy and strong, be careful.

Frozen yogurt and drinking yogurts follow the same rules: plain versions are fine, while toppings and dessert mixes may need a quick check.