What is nutritional yeast?

Nutritional yeast is a deactivated strain of Saccharomyces cerevisiae (the same species as baking yeast and brewer's yeast, but a different strain). It is grown on a nutrient medium, harvested, heat-deactivated so it cannot ferment, then dried and sold as flakes or powder. It has a savoury, slightly cheesy, umami flavour that makes it popular as a cheese alternative in vegan cooking. It is typically sprinkled on pasta, popcorn, salads, or blended into sauces.

How much protein is in nutritional yeast?

Nutritional yeast contains approximately 47g of protein per 100g — one of the highest protein concentrations of any food. However, typical serving sizes are small: one tablespoon (5g) provides about 2.4g of protein. To get a meaningful protein serving (e.g. 10g), you would need roughly 4 tablespoons (20g). It is a complete protein, containing all nine essential amino acids, which makes it particularly valuable for vegans.

Is nutritional yeast good for vegans?

Nutritional yeast is one of the most valuable foods in a vegan diet. It provides complete protein (all essential amino acids), is naturally rich in B-vitamins (B1, B2, B3, B5, B6), and the Marigold Engevita product sold at Tesco is fortified with vitamin B12 — the nutrient most commonly deficient in vegan diets. It also provides a cheesy, umami flavour without any animal products. At £4.00 for 100g from Tesco, it is a cost-effective way to supplement B12 and add protein to meals.

Glucose: Very LowNOVA 2

Nutritional Information for Nutritional Yeast

Nutritional yeast is a deactivated yeast sold as flakes or powder, popular with vegans as a cheese flavour substitute and valued for its exceptionally high protein and B-vitamin content. At approximately 47g of protein per 100g, it rivals whey protein powder. From a SpikeSaver perspective, nutritional yeast is NOVA 2 (processed culinary ingredient) — the yeast is grown, harvested, deactivated, and dried. It has a low GI and moderate carbohydrate content (19g/100g) with very high fibre (20g/100g). Tesco stocks only one product in this category: Marigold Engevita B12 Yeast Flakes.

Nutrition per 100g

Nutrient	Per 100g	Per serving
Energy	345 kcal / 1460 kJ	17 kcal
Protein	47g	2.4g
Carbohydrates	19g	0.95g
of which sugars	2g	—
Fat	5g	0.25g
of which saturated	0.8g	—
Fibre	20g	—
Salt	0.25g	—

Serving size: 1 tablespoon (~5g) · Source: Tesco product page, October 2025

Glucose impact

Glycemic Index

Very Low

Glucose risk

Nutritional yeast has a low glycaemic index due to its very high protein (47g/100g) and fibre (20g/100g) content relative to its moderate carbohydrates (19g/100g). A typical serving of 5g contains less than 1g of carbohydrates, making the glucose impact negligible. Even in larger portions (e.g. 15-20g used in a recipe), the fibre and protein content ensures slow, minimal glucose absorption. This is not a food that poses any blood sugar concern.

Processing level

NOVA 2 (processed culinary ingredient)

Nutritional yeast is classified as NOVA 2 — a processed culinary ingredient. The yeast (Saccharomyces cerevisiae) is grown on a nutrient medium (typically molasses), harvested, heat-deactivated, and then dried and flaked. The Marigold Engevita product is fortified with vitamin B12, which is an added nutrient but does not push it to NOVA 3 or 4. It contains no additives, preservatives, emulsifiers, or flavourings beyond the yeast itself and the added B-vitamins. It is used as an ingredient in cooking rather than eaten as a standalone food.

Nutritional Yeast at Tesco

Source: Tesco product page, October 2025

Marigold Engevita B12 Yeast Flakes 100G

£4.00*NOVA 2 (processed culinary ingredient)

*Prices were correct at the time of collection and may have since changed. Check Tesco.com for current pricing.

What to watch for when shopping

The main limitation for this page is product availability: Tesco stocks only one nutritional yeast product (Marigold Engevita B12 Yeast Flakes, £4.00/100g). This is a niche product primarily bought by vegans and health-conscious consumers. The nutritional profile is exceptional — 47g protein per 100g with 20g fibre and high B-vitamins (including fortified B12) — but the typical serving is very small (5g, about 1 tablespoon), so the per-serving nutritional contribution is modest. Nutritional yeast is not a significant source of calories or macronutrients at normal serving sizes; its value lies in flavour (umami, cheesy) and micronutrient fortification, particularly B12 for vegans.

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