I didn't add enough water. Can I add it now?

[Tinpanharry]

Noob here. Using a Coopers kit, I didn't fill up the fermenter to 23 liters this afternoon. I added it up to only 20. Should I add the additional 3 liters now, (disturbing the wort)? Or should I wait till fermentation is dones?
Thanks much!
TPH

 

[clydo]

I would add it now before it ferments. I would be very careful at this point to add water. Just be certain it's sanitized. You'll probably be fine without adding any, it will just have a higher grav. Leave it be and see how it turns out. Live and learn, ya know. It shouldn't be terrible and a Coopers kit isn't setting you back much anyway.

 

[codyjp]

https://www.homebrewtalk.com/f39/another-beginner-error-underfilled-fermenter-259223/

 

[Tinpanharry]

I would add it now before it ferments. I would be very careful at this point to add water. Just be certain it's sanitized. You'll probably be fine without adding any, it will just have a higher grav. Leave it be and see how it turns out. Live and learn, ya know. It shouldn't be terrible and a Coopers kit isn't setting you back much anyway.

Cool. I'll do that. Thanks!