Frozen yogurt

Yogurt ice cream with a pleasant tang. Lighter, but it needs careful balancing.

Frozen yogurt is a frozen dessert in which part of the dairy component is fermented by yogurt cultures — Lactobacillus bulgaricus and Streptococcus thermophilus. It differs from cream ice cream in its pleasant tang and, as a rule, lower fat. It tastes fresher and lighter, but that is exactly why it is harder to balance: with little fat, it tends to be icy.

According to Douglas Goff (University of Guelph), good frozen yogurt has two qualities: it contains live cultures, and its acidity comes from fermentation, not from added acid.

Origin

Frozen yogurt appeared in the 1970s in New England, in the north-east of the US.

Typical composition

ParameterGoff (formula)Commonly quotedzmrzka target
Fat2 %0.55–6 %0–9 %
MSNF14 %8–14 % milk solids8–15 %
Sugars (sweeteners)15 %15–17 %14–22 %
Stabiliser0.35 %—optional
Total solidsaround 31 %—26–40 %
Overrunvariable—20–50 %
Serving temperaturesoft-serve −6 to −2 °C—−14 to −10 °C from the freezer

In Goff’s formula, the fermented part makes up 20 % of the mix. It is skimmed milk with milk powder (12.5 % solids), incubated at 40–43 °C. The rest is a sweet dairy mix. At home, ready-made yogurt is usually used instead of fermenting your own.

Milk proteins in yogurt bind water and thicken the ice cream, but they barely lower the freezing point. Frozen yogurt with little sugar therefore tends to be hard. Greek-style yogurt has more protein and solids — according to USDA, full-fat Greek yogurt has around 9 g of protein and 5 g of fat per 100 g, full-fat plain yogurt about 3.5 g of protein.

Did you know?

Frozen yogurt does not contain less sugar than ice cream. According to the USDA database, it has around 127 kcal and 20 g of sugars per 100 g, vanilla ice cream 207 kcal and 21 g of sugars. Only the fat and calories are lower.

What the law says

In the US, frozen yogurt is not standardised at federal level.

In Slovakia

Under Slovak Decree No. 82/2018 it is a milk frozen dessert, and the word “milk” may be replaced with “yogurt”. The minimums for milk frozen dessert apply: at least 26 % solids, at least 6 % milk solids non-fat, at least 2.5 % milk fat and at least 2.5 % milk protein.

In Czechia

Czech Decree No. 397/2016 allows the word “mléčný” (milk) to be replaced, for example, with “jogurtový” (yogurt). A milk frozen dessert must contain at least 6.0 % milk solids non-fat and 2.5 % milk fat.

We do not use the word “probiotic” on zmrzka: health claims are strictly regulated in the EU and we have not verified the status of this claim. Details in the article Frozen yogurt and probiotics.

How to make it at home

The key rule: do not cook the yogurt. If you pasteurised it together with the mix, the cultures would die.

  1. Sweet base. Heat the milk (possibly with a little cream and milk powder) with the sugar, dextrose and stabiliser so they dissolve and the stabiliser activates.
  2. Cooling. Quickly cool the base to fridge temperature.
  3. Yogurt. Only then stir the yogurt into the cold base.
  4. Ageing. Briefly in the fridge — roughly 2–4 hours.
  5. Churning in the machine and hardening for about 2 hours.

The cultures survive freezing, but their numbers drop. A study in the journal Fermentation (2026) measured a drop of 0.4–0.8 log units on freezing and a further drop of 0.8–1.4 log units after 90 days at −20 °C. Frozen yogurt is therefore best eaten fresh.

Equipment: a compressor ice cream maker, a freezer-bowl machine or a Ninja CREAMi, which also copes with thick mixes made with tvaroh (quark) or skyr.

Recipes: classic frozen yogurt, Greek-style with honey and nuts, frozen skyr with vanilla and matcha yogurt ice cream.

Tip

For a thicker texture, strain the yogurt through a cloth or use Greek-style yogurt or skyr. This removes water and adds solids.

The most common mistakes

  • Pasteurising after adding the yogurt — it kills the cultures. Yogurt goes only into the cold mix.
  • Icy texture — too little fat and too few solids, no stabiliser. Milk powder, Greek-style yogurt or locust bean gum helps.
  • Rock-hard — too little sugar; protein cannot replace sugar.
  • Too sour — a lot of yogurt relative to the sweet component, or over-fermented yogurt.
  • Sandy — too much milk powder (the lactose crystallises).
  • Acid from fruit curdles milk in a warm mix — add fruit to a cold mix.

Warning

Do not give honey to children under one year old — not even in frozen yogurt.

How to recognise good frozen yogurt

  • It tastes pleasantly tangy, not just sweet with a yogurt flavouring.
  • It is smooth and creamy, without ice crystals.
  • It contains live cultures and its acidity comes from fermentation — the two criteria Goff recommends.
  • Yogurt is high up on the ingredient list.

How long it takes at home

StageTimeNote
Preparation10 minactive
Heating the sweet base15 minactive
Cooling1 h
Stirring in the yogurt and ageing2–4 hroughly
Churning in the machine20–30 min
Hardening2 h

Total: about 30 minutes of active work, 5–8 hours in all. If you ferment your own yogurt, add roughly 4–12 hours.

Equipment

Recipes (9)

Sources