European Fresh yeast cube = 42g = 2.5 cakes of yeast in the US
US fresh yeast cube = 17g or 0.6 oz
The rule of thumb is dividing or multiplying by 3:
from fresh yeast to dry – divide the amount by 3, eg. instead of 30g of fresh yeast use 10g of dry
from dry yeast to fresh – multiply by 3, meaning 7g or dry yeast becomes 21g of fresh.
10g of fresh yeast = 1 teaspoon of dry yeast
10 : 3 = 3.33 g
This is close to 3.5 g – the average weight of one level teaspoon of dry yeast. Teaspoon volume varies depending on the manufacturer and the shape. A few gramme more or less of yeast won’t make a huge difference in your recipe.
1 tsp instant = 3.1 g
1 g instant = 1.25 g active dry = 2.5 g fresh
1 tsp instant = 1.3 tsp active dry = 0.4 cake fresh
1 tsp active dry = 2.9 g active dry yeast
1 g active dry = 0.8 g instant = 2 g fresh yeast
1 tsp active dry = 0.75 tsp instant = 0.3 or 1/3 cake fresh
1 g fresh = 0.5 g active dry = 0.4 g instant
1 cake fresh = 3 tsp active dry = 2.25 tsp instant