Volunteering in soup kitchens or other facilities to help the poor and the destitute is a great virtue. I would commend you for such works.

 

If the people you are serving food are sickly or older adults, then there is no reason to stop doing it in Ramadan or any other time.

 

If that is not the case, then you should ask if you can do so after the month of Ramadan, especially if you have to serve food during the day hours while fasting.

 

Alternatively, you may also choose to volunteer at night (as long as you do not compromise your spiritual regimen of the Ramadan.).

 

Almighty Allah knows best.