Did I Manage To Kill My Yeast?

[eddy401]

Ive had 23L of brigalow 'premium bitter' fermenting for 4 days now (only my 3rd brew), i added 1kg dextrose and 500g DME and the kit yeast. it was bubbling away nicely yesterday, every 2 seconds or so - then i decided after a few beers myself to add some orange zest to it, so i zested a few oranges and soaked them in boiling water - yep, without realising what i was doing i poured in the near boiling hot water (about half a cup). the airlock hasnt bubbled since, even though ive left it over night. ive given it a swirl and taken a gravity reading, and the lid is on tight.
firstly, could that have killed the yeast? or just some and it has to re-populate and i just slowed the process down?
secondly, if i did kill the yeast how would i tell?
could it have finished fermentation? it was bubbling really quickly before, i suppose the sg reading will tell me that.
and finally, if they are dead could i just throw in some more? and would it matter if it was a different kind?
sg now (the first reading, have to do it again in 24 hrs) is 1018

thanks!

 

[manticle]

Pretty unlikey that half a cup of boiling water will kill the yeast. Most yeast will survive temperatures up towards 50 (from memory). I doubt you would have raised the total temp more than a degree, if that.

Bubbling is not a reliable sign of fermentation. If it happens at all it will slow down in the latter stages and even stop. You may have just not sealed the lid properly second time around. Wait until you get a stable gravity reading and make sure that reading is in the ballpark area you would expect. With 1 kg of dex plus 500g malt I would hazard a rough guess you should get to at least 1012.

 

[raven19]

It definately has not killed all your yeast, as per Manticle's post.

Give it another swirl if your next reading is still around 1018, but in any case give it time, relax and have a home brew! :icon_cheers:

 

[eddy401]

thanks for the fast replies! :beer:

 

[eddy401]

its started bubbling again, not sure why it took so long to start again but im happy! just out of curiosity though, (from when i asked if you could add more yeast, and if another kind would matter) would adding more than one kind of yeast have any good/bad effects? my guess is that one type would be slightly better suited to the conditions than the other and the other would disappear...?

 

[roverfj1200]

Hi Have pitched s-23 on 34/70 as it was taking a long time to kick in. The beer was great.

 

[thesunsettree]

its started bubbling again, not sure why it took so long to start again but im happy! just out of curiosity though, (from when i asked if you could add more yeast, and if another kind would matter) would adding more than one kind of yeast have any good/bad effects? my guess is that one type would be slightly better suited to the conditions than the other and the other would disappear...?

hi mate,

think of it like this - when u have an airlock it releases a very small amount of gas at regulated times as the pressure slowly builds up. when u take the lid off the entire cm2 of co2 is released in one complete hit, so when u put the lid back on it takes a certain amount of time to 'rebuild' that pressure. this time might take longer than the intial yeast activation as some of the sugars have been gorged by the yeast (typical of when the ferment slows down). i have added a second yeast once, a lager yeast ontop of a ale yeast, it was drinkable but not great, but certainly dont take that as a standard.

cheers
matt

 

[WSC]

Yeast is pretty tough.

I added about 10 litres of hot tap water to a yeast cake the other night and it was already 30 degrees, temp went higher than the sticker on the fermenter could register.

I thought I had stuffed it completely, go to the shed the next morning and it was bubbling away.

It was a Saison yeast though and tasting the hydro sample seems to have had no ill effects.

Note to self....pay more attention when brewing at 11pm .....