How much yeast to use?

[Garndtz]

I am a wine making newb and I need some help.

I am making a 1 gallon batch with a recipe that just says add yeast. My yeast packet says it includes enough yeast to make 5 gallons. Should I just use 1/5 of the yeast packet? Any thoughts?

Thanks much!

 

[oxeye]

Most yeast manufacturers say that a 5 gram packet of dry yeast is for 1 to 5 gallons of must.

I once used a packet of yeast divided into forths for 4 different gallon jug batches, and got perfect results.

The whole 5 gram packet is not too much for one gallon!

But, once you open the packet and only use part of it, you had better use the balance pretty quickly, or it will run the risk of contamination even in the fridge.

If I had more batches planned in a day or so, I'd probably risk it. Other wise, you will most likely lose what you don't use and then contaminate and lose some expensive fruit or juice when you do get around to using it.

oxeye

 

[Wine Maker]

If you use too much yeast you shouldn't have a problem, once all the sugar is consumed by the yeast and turned to alcohol any remaining yeast should drop to the bottom of whatever you are fermenting the wine in. If you are making only one gallon I would divide the packet in half and use just half.

 

[Luc]

Yeast will multiply each hour.
So when you add half, an hour later the population has doubled
and is on the same level as when you would have added the whole package.

So when you add 1/5 th. Next hour it will be 2/5, the hour afther 4/5th and the next hour (so after 3 hours) more as you started with.

To put this differently within a few hours there will be more living yeast cells in your must as there were in the original package you started with anyhow.

Manufacturers put as much in a package as they reckon is a safe amount to get a certain volume fermenting as fast as possible.

So if the package is for 5 gallon, and you add one-fifth to a 1 gallon batch you should be safe.

The set back is that a sealed package yeast will be exposed to air as soon as it is opened. Air contains some moisture and so some yeast cells will be 'wakened'. Therefore they will start to live and do not have any food etc to live on and they will die in the package.
So any remaining yeast that is in the package and not used will have therefore less living yeast cells.

So when you store the remaining yeast you better make a yeast starter next time with it to make sure you have a health yeast colony to add to your must.

Best way to store the opened package is to store it air-tight in the fridge (not in the freezer).

But saying all this: why bother.
Yeast is not expensive so toss it all in.

Luc

 

[PricklyPear]

According to a guide of Lallemand I read you should use about 25 grams per hectoliter (100 liter).

By the way, last year I was using the same pack of yeasts for a long time (and stored it open in the refrigerator in between) and had no problems with the yeasts.