Strange thing happening to grout

[emmaamme]

I was just wiping down our walk in shower this evening when I noticed some of the grout looked strange (but only on one wall).
Its been there 3 years so not new but if I run my finger along it it seemed to be coming off when wet which seems very odd & I don't understand how that could happen after 3 years.
I've attached a few photos. It's almost like a paste. Can anyone explain this please?

 

[CBW]

Looks like solidified soap residue.

 

[emmaamme]

Ah so it's maybe just a build up of soap products rather than a problem with grout you reckon?

 

[CBW]

I’d say it’s likely.

 

[emmaamme]

Thanks - I'll give it a good scrub & see what happens

 

[foxhole]

Looks like solidified soap residue.

Yeh, give it a clean.

 

[emmaamme]

Gave it a good clean & looks better although the portland type colour appears to have turned white. Checked other bathroom & same has happened to grey grout on same wall (opposite wall to where shower head is). Wondering if its maybe some type of efflorescence?

 

[foxhole]

Gave it a good clean & looks better although the portland type colour appears to have turned white. Checked other bathroom & same has happened to grey grout on same wall (opposite wall to where shower head is). Wondering if its maybe some type of efflorescence?

Limescale , lack of cleaning