Ruling on eating pickles and bread made with yeast in the dough

Firstly: 

The general principle with regard to foods is that they are
permissible, and nothing is disallowed except that for which there is
evidence that it is haraam and should not be eaten. 

But the problem is the use of yeast in these pickles. 

It says in al-Mawsoo‘ah al-‘Arabiyyah, under the
heading Khameerah (yeast): 

Yeast is a substance that ferments the dough when making
bread. Its effect is the formation of carbon dioxide which created bubbles
that make the colour of the dough lighter, and makes the dough expand during
baking and rise and increase in size. Yeast is also used to make beer,
nabeedh and other alcoholic drinks. The he yeast that is used commercially
is made from colonies of microscopic single-celled yeast organisms. Although
there are more than 600 kinds of yeast, only a few of them are used
commercially. 

Based on that: 

If the amount of yeast in these pickles and the like is very
little, and it has dissolved in them, so that it does not have the effect of
causing intoxication or languor, there is nothing wrong with using yeast in
them, and eating these pickles. 

But if the yeast has a lasting effect on them, such that if
the one who ate a lot of these pickles would become intoxicated or tired, it
is haraam to use the yeast in them, or to eat anything to which yeast has
been added in this way. 

Thus it become clear that pickles made from permitted foods
are permissible. It should be noted that the vinegar which is put with these
products or that is produced by pickling these materials, comes under the
heading of drinks that are originally permissible, and is a type of food
that the Prophet (blessings and peace of Allah be upon him) ate and praised,
saying, “What a good condiment is vinegar.” [Narrated by Muslim, 2051]. 

For a more detailed discussion on the ruling on vinegar,
please see the answer to questions no.
106196 and
113941. 

Secondly: 

There is also nothing wrong with eating bread made with
yeast. The yeast (khameerah) that is added to the dough does not come under
the heading of khamr (intoxicant) that is haraam, and does not have any
effect of causing intoxication or languor, especially since cooking it with
fire alters the yeast completely, so that it no longer has any effect. 

Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allah have
mercy on him) was asked:

How should we respond to the ruling on the yeast that they
put in flour to help leaven it and make it easy to cook, as some people say
that it is khamr and it is not permissible to use it? 

He replied: 

My response to that is that there is nothing wrong with
putting yeast in the dough for the purpose of leavening it, because this
does not affect it at all. Moreover, I do not think that this yeast would
cause intoxication if a person were to eat it. The basic principle
concerning all foods and drinks and clothing is that they are permissible,
unless it is proven that they are haraam, because Allah, may He be exalted,
says (interpretation of the meaning):

“He it is Who created for you all that is on earth. Then
He rose over (Istawa) towards the heaven and made them seven heavens and He
is the All-Knower of everything”

[al-Baqarah 2:29]. 

So there is nothing wrong with putting yeast in the dough to
leaven it. 

Fataawa Noor ‘ala al-Darb (tape
70, side b) 

And Allah knows best.