What is the minimum amount of food required to CONTRACT ritual impurity?
Halacha 1 states: 'For them to contract impurity, even the slightest amount. Even a sesame or mustard seed contracts impurity.' The egg-size is required to IMPART impurity, not contract it.
Question 2
What is the status of an egg-sized portion of food that was left in the sun and shrank?
Halacha 4 states that when egg-sized impure food is left in the sun and shrinks, it no longer imparts impurity. Similarly, shrunken carcass portions and creeping animal portions also lose their impurity transmission capacity.
Question 3
When an egg-sized portion of food that was a primary derivative of impurity is mixed with an egg-sized portion that was a secondary derivative, what is the status of the mixture?
Halacha 12 states that when a primary derivative portion and a secondary derivative portion are mixed, the entire mixture is considered as a primary derivative.
Question 4
When the mixture in question 3 is divided again, what is the status of each portion?
Halacha 12 states that if the mixture was divided, each portion reverts to its original impurity level — the originally primary portion is primary, and the originally secondary portion is secondary.
Question 5
Can foods of different impurity levels be combined to reach the egg-sized minimum measure?
Halacha 10 states that entities can combine only if both their type of impurity and their minimum measures are identical. If either differs, they cannot be combined.