2,394. What Is Meant by "Touching"

Maachalos Assuros 11:26

If someone is a houseguest in any time and place and his host brings him wine, meat, cheese or fish, it is permitted without the guest having to ask about it. This is so even if he doesn’t know his host at all aside from the fact that he’s Jewish. If the host is known to be non-observant and not careful in these matters, then it’s prohibited to be his guest. If one violates and becomes this person’s guest, it is prohibited for him to eat meat or to drink wine until a person with a reputation for being observant vouches.

Maachalos Assuros 12:1

When we speak of an idolator touching wine and rendering it prohibited, we mean touching the wine either with his hands or with any other limb that might normally be used to pour a libation and shaking the wine. It’s not prohibited if he stuck his hand into a barrel and his hand was grabbed before he could remove or shake wine from it. If the barrel was opened towards the bottom and the wine was permitted to flow out until it reached below his hand, it isn’t prohibited. Similarly, if the idolator held an open vessel of wine and shook it, the wine is rendered prohibited even though he didn’t raise the vessel or touch the wine.