tmanlua

Recipes 

I'm making a quad with a predicted OG of 1.09. I went to make a .5L starter, and in the process of pitching the yeast had a big clump come out of the yeast vial and end up on the floor. I might have lost anywhere from 20% to 80% of the yeast in the vial. I contemplating brewing on schedule anyway but thankfully timing didnt allow and I am putting off brewing for at least a couple days. My questions are:
1) Given that I lost a fair amount of yeast should I just start over and go buy some more yeast? Or will the starter make up for any lost yeasties.
2) Whats the best way to keep my starter viable given that brewing will be put off any where from 3-7 days?
Thanks for any help.

Jmiltime

Recipes 

tmanlua, that's a bummer to have an accident like that as you are prepping for a brew day. However, here is how I would answer your questions:
1 - I would go get some more yeast. If you lost that much, it would take at least 2 step-up starters to get enough yeast to pitch in a beer of that gravity. Another option would be to get a new pack of yeast and combine it with what's in your existing starter and you may be okay with pitching rates.
2- To keep your starter viable, let it work for the full 3 days, then cover it and keep it refreigerated until you need to use it. If you have 7 days, you may try pouring off the beer in the starter (wash yeast) after 3 days in the starter and make another starter to step up your yeast count.

Either way, without multiple step-up starters you will probably be way underpitching your yeast and if it were me, I would get another package of yeast.

Good luck!

TipsyDragon

Recipes 

1) the starter will make up for the lost yeast. that's the whole point of making the starter.
2) stick it in the fridge.

by the way, a half liter is way not enough for a beer with a gravity that high. you need at least a 2.25 liter starter for a 5 gallon batch.

Jmiltime

Recipes 

The point of making a starter is to get yeast to an active and healthy place to quickly start an active fermentation, and to get yeast to proper cell count for pitching. A starter only increases your cell count by about 30-40% which is what most vials/smack packs need just to have proper pitching rates for an average gravity (1.050) beer. If you lost 20-80% of your yeast in a spill, a normal starter won't get you near proper cell count, especially for a beer that big. Either you will need to buy more yeast (preferably at least 2 vials/smack packs) or make multiple step up starters to get your yeast count to where it needs to be.

You may be able to salvage the little amount of yeast you have in the starter, but just know it will not even be close to enough for that beer.

Good luck!

EricCSU

Recipes 

This.

According to Mr. Malty, you need two vials in a 2.39 liter simple starter and 2 vials in a 1 liter stirplate starter.

__________________
Kegged: Belgian Dark Strong (8.9%abv)

Fermenting: Arrogant Bastard Clone, BCS Dry stout

Planned: Rye IPA, ESB, Oatmeal Pale Ale, Rye Amber

Can You Brew It Recipe Database
Convert an all grain recipe to extract
Hop Substitution Chart