Testing Yeast

[stanglish]

Yep, it's a newbie question but recently I had a disaster with some Youngs Super Wine Yeast compound. Brewed a couple of juice wines (Ribena ready to drink & Polish Syrup) and they did absolutely nothing (checked via gravity). I've had nothing but success with actual kits and even put on a couple of flavoured wines which came with their own yeasts soon after which went off like a rocket. Environment was the same, so were sugars, so was sterilisation & water.

To try and prove out the yeast I took 300ml water at 35 degrees, a couple of spoonfulls of sugar, and a spoonful of the yeast compound. I covered and left for 24 hours - it did nothing, nada, zilch. No bubbles, no noise, nothing to prove it started fermenting.

Anyway, I just so happen to have some more on it's way. Does anyone have any foolproof suggestions regarding how to get some faith in it before I brew with it? The above seemed sensible but I'm sure long-time brewers might have something to add here.

Apologies if the topic has come up elsewhere - had no luck with searching.

 

[Chippy_Tea]

I started wine making using Youngs super wine yeast and other than when i make kits i never use anything else, i have never had a WOW or supermarket juice based wine fail to finish.

You say you added the yeast to water at 35, the WOW guides and kits instructions say to pitch the yeast at temperatures under 25c, could the high temperature have stopped the yeast doing its thing?

 

[stanglish]

Could well be it. When the other comes I'll do a similar test but with 25 degree or cooler water. I think I possibly do have a bit of a mental block in place about things needing to be warm - but I honestly don't remember the actual brews being subjected to anything even approaching those temps. Hmm :pray:

 

[Chippy_Tea]

When i make my WOW variants i let the hot sugar water cool to 40c then add it to the 3 litres of cold supermarket juice in the DJ, this brings the temperature down to the low 20s which i guess gives the yeast the best start it can get.

 

[MandiNKel]

I think you've hit the nail on the head, I never pitch before the must is at room temp.
With some wines I make a starter to give the yeasties a head start, especially do this when making Skeeter as pitching straight in they have no chance.

 

[Robbo]

I used Lalvin K1-V1116 and on the back of the sachet it states to rehydrate put the yeast into 50ml of 40 to 43c water.

It worked, but seems a bit on the hot side as i try to keep fermenting temps to around 25-28c.

 

[Brewtrog]

cup of water at 30C or under, 1 or 2 tsp sugar dissolved in it. put a tsp of yeast in, wait 15 mins, if the yeast is viable there will be froth. You can then put this starter straight into your must. (you can also just do the same thing with the must)