How long will a yeast starter stay viable?

I made a yeast starter on Friday with the plan on brewing on Sunday. On Sunday something came up and I was not able to brew. Now I won't be able to brew until next Friday.

Will the yeast starter stay viable until then? Should I put it into the refrigerator and then take it out 48 hours before brewing? Then maybe pitch some more DME into the starter? Maybe a little more water?

This yeast is a Safale -04 washed yeast from a previous batch. Any guidance would be appreciated.

Hi Greg,
Your starter will certainly be viable a week later. They're hearty creatures, as evident by brewers being able to use yeast that is 45 million years old.

Yes, put it into the fridge and take it out on brew day. Pour off the liquid (although you don't have to) on the top and give the yeast a few hours to come up to room temperature. Then pitch as usual. You'll be fine without adding any extra wort.

Thanks for getting back to me on this. Cal Poly San Luis Obispo is my Alma Mater where Raul Cano the professor credited with isolating that yeast strain teaches. That's a great back story for a beer, 45 million old origins. They call it Fossil Fuels Brewing Company

stick the starter in the fridge and leave it till brew day. take it out at the start of your brew day and let it sit for 3-6 hours so it can warm up to room temp.

No problem

That connection is one to be proud of. I'd be tossing it out at the bar every chance I got. I didn't know they had a brewery and website now (and a darn pretty one). Not sure if the beer is any good but it's going on my "must drink before I die" list. Thanks for the info.