Is my yeast unhappy?

April 29, 2005 1:50 PM

Is my yeast unhappy? Beginner's homebrewing question inside.

I'm making dandelion wine. It's been a pretty low-tech project — just a jug, an airlock, a recipe from the web and a packet of dry winemaking yeast.

The airlock is bubbling very slowly right now — only one tiny bubble every few minutes. This is my first homebrewing project, so I have no idea what's normal, but I'd have expected a lot more activity in there. The yeast is still alive, though. If I throw in a pinch of sugar, it foams right up all excitedly. And then after a minute, it slows back down again.

Is this normal? Or should the yeast be more active?

If it isn't normal, is the solution to add more sugar? Or is there something else that could be causing the problem?

posted by nebulawindphone to food & drink (9 answers total)

When did you start it?
posted by MrMoonPie at 1:53 PM on April 29, 2005

About two weeks ago.
posted by nebulawindphone at 1:55 PM on April 29, 2005

Oh, then I'd say it's probably all done.

There are a lot of variables, but my batches can take up to three days to get really moving, especially if the ambient temperature is low. Then active fermentation is over in three days or so. After that, a bubble a minute is about right.

The pinches of sugar probably aren't actually stimulating the yeast, but causing cavitation; yeast isn't that immediately reactive. If you threw in a pinch of salt or sand, you'd likely get the same reaction.
posted by MrMoonPie at 1:57 PM on April 29, 2005

Yeast (or more correctly, their enzymes that process the sugar into carbon dioxide, alcohols, adehydes and other sugars byproducts) operate most efficiently at a certain temperature. If your starter yeast is in a cold or cool room (55-65ºF), consider gently warming up the yeast another 10-20ºF.
posted by AlexReynolds at 1:57 PM on April 29, 2005

I should add that my experience is with 15 years or so of beer and (grape) wine brewing, not dandelions. But I'd be surprised if the processes were very different.
posted by MrMoonPie at 1:58 PM on April 29, 2005

Did I use "cavitation" correctly? I mean the little granules are giving carbon dioxide bubbles sites to form.
posted by MrMoonPie at 2:01 PM on April 29, 2005

nucleation, not cavitation. Sorry.
posted by MrMoonPie at 2:03 PM on April 29, 2005

Was there a lot of activity early on, or has it been slow the whole time? If it was active early on, then the suggestions above are correct - your fermentation is done or close to done. You'll probably be ok this time, but for next time, get a hydrometer. It measures specific gravity, and monitoring the specific gravity is the only reliable way to see how your fermentation is doing. A hydrometer can be had for around $10 at your LHBS (Local Home Brew Supply).

Also, I'm not sure whether it was such a good idea to add sugar in there. If the sugar is not sanitized (i.e., boiled), you could introduce bacteria, which can give you off-flavors. If for some reason the fermentation is indeed stuck or never got started to begin with, more sugar will not help. Instead, you would need more yeast.

But don't worry too much. First time brewers are exempt from all of the rules and usually end up quite pleased with their results. (sort of like first time poker players)
posted by jclovebrew at 2:09 PM on April 29, 2005

(I was wondering what 'cavitation' meant in this context...)

Sounds like it's done, then — it did get off to a roaring start, which is why I was so surprised when it slowed down. I guess I'd just been expecting it to take longer. Thanks everyone.
posted by nebulawindphone at 3:02 PM on April 29, 2005