Is My Yeast Dead??
Yeast are our best friends, but they don't always do what we think they're supposed to. That feeling you get when you check on the beer recipe you just brewed after two days, and your airlock isn't doing anything, is usually panic. There's nothing worse than putting all of that love, time and money into your brew, then checking on it and seeing that it's not doing a damn thing!
Just remember, don't panic! There are a few different things that can go wrong, and sometimes, it's equipment failure and not yeast failure!
Step 1: Always Check Your Gravity First
The best way to tell if your yeast is alive and fermenting is by checking the gravity. Even after a couple of days, your gravity will read differently than when you first pitched your yeast. Yeast use the sugar in your wort for replication before they even start fermenting, so it's a sure fire way to know if anything untoward is going on.
If your gravity has gone down, but your airlock isn't moving, then you know that you have a leak in the lid of your fermenter. This is especially common in buckets, but can happen in any vessel. Nothing to panic about if the yeast are working, just don't do any bulk aging in that vessel. Once the CO2 that the yeast are producing stops, you can open your beer up to infections and funk that you don't want.
Step 2: What If The Gravity Hasn't Changed?
If you check your gravity, and nothing has changed, then it's time to do some detective work. First and foremost, do a little research on the yeast strain you're using. Some strains are just plain slow, and sometimes strains from certain manufacturers can be on a delay, for whatever reason. If this is the case, then you're still fine. If not....
Then it's time to think about brew day. How was your yeast wrangling that day? Did you forget to let your yeast warm to the same temperature as your wort and pitch it into warm wort at refrigeration temps? This can be a HUGE shock to the yeast. A degree or two isn't a big deal to us, but to a single celled organism, it can be a big shock, and many of your yeast cells may have paid the ultimate price. In this case, the yeast will still work, but fermentation will be stalled. Dissolve some Fermaid K in some boiled or otherwise sanitized water, and pitch that into the wort to give the cells that made it the extra nitrogen and nutrients they need to replicate enough cells to ferment your beer and have a clean fermentation. You can pitch another pack of yeast at this point, but most of the replication has been done, and nutrients will do more for your beer.
Maybe you let the yeast warm up, but for one reason or another, the wort was still above 90° F when you pitched them. This is the same situation, big shock for little yeast cells, and can also cause a stalled fermentation start. Give them some Fermaid K, and you'll be just fine.
The thing to remember about yeast is that they are living organisms, and want to stay that way. We have done tons of experiments with old yeast, shocked yeast and hot pitches, and more often than not, the yeast will survive and do their job. Depending on the strain, you can still make a pretty good beer, but fresh yeast, proper pitching rates, and solid fermentation temps will always make better beer. At the end of the day, ALWAYS have fun and remember that homebrewing isn't always a competitive sport!
In the end, it comes down to this small, yet mighty, checklist:
- Don't Panic
- Check Your Gravity First
- Keep Not Panicking
- Know Your Yeast Strain
- Follow Good Yeast Wrangling Habits
- Have Yeast Nutrients On Hand
Another good option, and a fail-safe that I have always used, is to have an array of dry yeast strains on hand. Dry strains, while they don't offer the variety of liquid strains, have a crazy long shelf life, and if you cover your basics, i.e. an American strain, a few British strains, a Belgian strain, a lager strain, and maybe a wheat strain or two, you'll always have a back up if disaster strikes!