Storing open packets of dried yeast??

[Swift Pint]

I brew in either one or two gallon batches and have previously just used a whole packet of dried yeast.
However I feel that this is over kill & am worried about overpitching, so am going to scale down the amount of yeast I use to a more appropriate level.
Does anyone have any experience of how to store dried yeast once the packet has been opened? Should I sanitize some small ziplock bags and use them? Or is it not worth the risk of contamination? I'd prefer not to be throwing away good yeast...
Would I be better off making small starters and storing the yeast that way??
:wha:

 

[RobWalker]

You have almost no risk of infection. It's dried, stuff won't grow on it - i just fold the packets over and i've used them months after and not noticed anything wrong. montrachet wine yeast comes from the HBS in a 10-use tub too, just dip a teaspoon in!

instructions on Munich say to store in the fridge and use in 3 days, but i really don't see the point when it's blatantly fine. all you need to watch is that the number of active yeast cells will gradually drop, so it's probably worthwhile to make a quick starter up when brewing. I do this a few hours before pitching (with sugar even works) and it's active enough to get your brew going straight away :thumb:

 

[Swift Pint]

perfect, thats me sold :thumb:

 

[LeedsBrewer]

I was wondering the same thing. I only do small batches and used half a pack of S04 which has been taped up and in my fridge for a month. Was wondering if i could reuse it or not. I suppose if you rehydrate for 15 mins and then add some dme or sugar, after another 15 mins you'll probably see if the yeast is active or not.

 

[RobWalker]

I was wondering the same thing. I only do small batches and used half a pack of S04 which has been taped up and in my fridge for a month. Was wondering if i could reuse it or not. I suppose if you rehydrate for 15 mins and then add some dme or sugar, after another 15 mins you'll probably see if the yeast is active or not.

precisely - it's worth bringing them to room temp before pitching too.

 

[Good Ed]

I was wondering the same thing. I only do small batches and used half a pack of S04 which has been taped up and in my fridge for a month. Was wondering if i could reuse it or not. I suppose if you rehydrate for 15 mins and then add some dme or sugar, after another 15 mins you'll probably see if the yeast is active or not.

don't use sugar :nono: and also no need to use dme, the yeast is designed to be hydrated with water

 

[Baz Chaz]

I used dried yeast making the bread, I store the part used packets in the fridge.

Cut the corner of the packet, measure out yeast, 're-seal' the pack with sellotape, stick in fridge door, never had any problem :thumb:

 

[LeedsBrewer]

I agree that you should always rehydrate with water only, but I was reading a paper the other day that said that you should either pitch yeast after rehydrating in water for 15 mins or add dme or must to it otherwise the yeast will start to starve. This is why lalvin packs recommend not rehydrating any longer than 15 mins.

As regards to using sugar i've heard some people say not to. I understand that DME is probably better to use but (i've usually already put that in my FV!) why should sugar not be used?

Using sugar is the method recommended by Palmer:

Re-hydrating Dry Yeast
1. Put 1 cup of warm (95-105F, 35-40C) boiled water into a sanitized jar and stir in the yeast. Cover with Saran Wrap and wait 15 minutes.
2. "Proof" the yeast by adding one teaspoon of extract or sugar that has been boiled in a small amount of water. Allow the sugar solution to cool before adding it to the jar.
3. Cover and place in a warm area out of direct sunlight.
4. After 30 minutes or so the yeast should be visibly churning and/or foaming, and is ready to pitch.

Edit:
Good Ed, just reread your post. The adding of sugars was suggested to see if the yeast is active before pitching, otherwise you could be pitching dead yeast.

 

[Good Ed]

I'm not sure of a really scientific answer why not to use sugar with yeast; but most of the sugar in your wort is maltose and beer yeasts have evolved to use this, they also utilise other sugars that are in your wort. So you want your yeast to be ready to utilise the maltose in your wort, the problem with sugar in a starter is that it is made up glucose, sucrose and fructose (in varying amounts I think) so you are getting your yeast active on sugars that you don't want them to get used to, and also this may hamper their ability to use maltose, they then have to adjust when you pitch into your wort that is predominantly maltose, with a result of cells dying off, being stressed (off flavours) and a longer lag time while they adjust.

 

[LeedsBrewer]

I'm not sure of a really scientific answer why not to use sugar with yeast; but most of the sugar in your wort is maltose and beer yeasts have evolved to use this, they also utilise other sugars that are in your wort. So you want your yeast to be ready to utilise the maltose in your wort, the problem with sugar in a starter is that it is made up glucose, sucrose and fructose (in varying amounts I think) so you are getting your yeast active on sugars that you don't want them to get used to, and also this may hamper their ability to use maltose, they then have to adjust when you pitch into your wort that is predominantly maltose, with a result of cells dying off, being stressed (off flavours) and a longer lag time while they adjust.

That's enough of a scientific answer for me :thumb: makes sense and my brain didnt melt too much.

 

[JimmyB78]

Could I use a little bit of my wort instead of sugar/dme? Then it's used to the good stuff straight away?

So while the main volume of wort is chilling take a little out to chill quickly and use in the yeast starter

 

[Good Ed]

Could I use a little bit of my wort instead of sugar/dme? Then it's used to the good stuff straight away?

So while the main volume of wort is chilling take a little out to chill quickly and use in the yeast starter

No, dried yeasts are designed to be rehydrated with water, it's that simple. And you are rehydrating the yeast and not making a starter.

I've found a post, one of many on here and on Jim's, only read Aleman's comments, I know he is blue in the face from advising people on this subject :shock: http://www.thehomebrewforum.co.uk/viewtopic.php?f=36&t=29811&hilit=rehydrate+yeast