Thursday 22 November 2012

it lives

So I tested my yeast this last weekend.

The results were not exactly conclusive.

Well, I say that - I did reach a firm conclusion that the new yeast I brought is definitely okay and a packet of yeast I opened from the last batch is also probably okay.  However, as to whether the older yeast is okay, I am of the feeling that it is not, but my results were cast into doubt by the new yeast.

Let me explain.

Basically, my main theory as to why my bread recently has not been rising was either that the yeast I was using is dead/contaminated/not working very well, but I was also suspicious that temperate was an issue.  With the recent down-turn in temperature I was suspicious that the yeast was not getting fully activated and hence not rising properly.

That would explain why the bread rises were poor, but not completely absent - the bread wasn't like an unleavened bread, but was only about a third of what it should have been.

As such I looked up testing the yeast - what temperature to use - and discovered it was actually surprisingly warm (115F - 120F).  You also put in some sugar to give it something to feed on and give it 10 minutes - no rise = dead yeast.

So I gave this a go and got a very result from my old yeast - a slight scum, but nothing to write home about.  I then tried it again using my brand new yeast and the other packet I opened from a few weeks back.  And I got mixed results - the new yeast went bonkers and the older yeast was somewhere in between.

However, the problem was I was not particularly stringent on the temperatures.  The last one with the brand new yeast I did at the proper temperature range.  The mid-age yeast I did at a warm temperature but a good way below the recommended range and the old yeast I was quite a long way below.

Now I'd not been stringent because I hadn't thought it would make a big impact, but essentially I effectively got results of: very low temperature = poor result; medium low temperate = okay result; correct temperature = great result as well as the age factor.

In other words I didn't conclusively prove that it's the yeast that's bad, only that I need to be more precise with my temperatures before I can be sure.

However, I did use the two yeasts that had worked to bake loaves and got some awesome results.  I'd worried that the bread maker might be faulty, but using the new yeast in there it produced an excellent loaf and using the medium-age yeast to hand-make a loaf I got an excellent result too.

I quite like hand-making, but it can be a bit messy and is a hell of a lot more faff than just sticking it all in the machine.

Still, now I can at least test the old yeast properly next time and see if it is duff.

No comments: