My beer is 1022; Can I bottle it?
by manticle on 08-28-2010 at 05:55 am

"FG at 1022. Should I bottle"?

NB: This question (or variations thereof) seems to come up so often, I'm surprised there isn't already an article on it. I looked, found nothing so if I'm wrong, a moderator could remove it.

I'm not an expert brewer so if modifications need to be made to this article by someone who is then please feel free. Edits should be considered, well structured and clearly written.

WORKING OUT IF YOUR BREW IS READY TO BOTTLE

Quite often new brewers ask if their brew is OK to bottle as the gravity is much higher than it says on the tin. Even more experienced brewers sometimes wonder if the gravity they have means the brew is finished. People often trot out the old 'if the gravity is stable over three days then it's finished' but this statement, in and of itself means nothing. Some yeasts are slower than others. Some attenuate differently. There are many factors involved in reaching final gravity. Some brews will slow right down towards the last few points. Sometimes yeast will slow or seem to stop working altogether. If you bottle based solely on the three day premise, you may end up with glass all over the shed, in the ceiling or in your eye (or pet's eye, kid's eye etc). Exploding glass is not fun.

So we've established that it's not a good idea to bottle if the gravity is too high. The reason for this is that yeast produces carbon dioxide as it works on eating the sugar. Gravity is a measurement of the available sugar in the brew (put simply). If there is some sugar left to eat and the brew is bottled inside a sealed, glass container, that carbon dioxide has nowhere to go. When brewed and bottled correctly this allows the beer to carbonate naturally to a controlled level. When bottled incorrectly it can cause glass to explode which is at best a waste of beer and a sticky mess: at worst, it's a nasty injury to someone.

Final gravity is dependent on a few things: namely ingredients, yeast and mash and fermentation schedule. If you are a kit or extract brewer then the mash part has already been completed.

What to do if your brew seems stalled? Well the first thing to do is to NOT panic. If your brew sits for a bit past final gravity, it will do the beer no harm and probably will do it some good. Patience is key to making good beer and beer conditions/matures better in larger quantities than small. I recommend leaving beer for a few days (minimum) past FG in any case.

The second thing is to figure out if it really is stalled. Not every brew finishes at the same point (one reason not to rely on the green 'beer finish' zone on a hydrometer).*

This means if/when you think a brew might be stuck, it is a good idea to consider what went into the brew. Did you include any less fermentable sugars such as lactose? Did you add dextrins in the form of maltodextrin or cara-pils? Is it an all extract brew? Was the original gravity high? Did you pitch enough yeast?

Then it's a good idea to consider how the brew was made - did you mash high (only relevant to mash brewers)? Is your temperature measuring accurate (relevant to mash brewers when mashing and kit/extract brewers when fermenting)?
Fermentation temperature being too low might prevent the yeast from working. If this is the case it may be roused again by higher temperatures - something that can be dangerous if you decide to bottle. Hopefully I've made my point. Assessing ingredients and process can give you an indication as to where you might expect a brew to finish. Don't worry too much about 1 or 2 points; you are looking for a range. If that range starts to look wide (and I would consider 4-5 points verging on wide, brew dependent) then that's when you need to exercise caution. If you added dry enzyme, expect that range to go much lower.

All decent yeasts should come with a suggested attenuation range. Attenuation is how much of the available fermentable material a yeast strain will be likely to eat. Additionally different strains will have different alcohol tolerance thresholds. Once the alcohol level gets to a certain point, the yeast might be unable to continue as their environment becomes toxic. For example, if you have a brew that starts at 1.130 and you add a yeast that has a threshold of 7% ABV then it won't get to 1.012 and no amount of rousing tricks will make it happen (short of pitching new, more capable yeast).

The Fast Ferment Test

The best way to tell if your brew is stalled** and what final gravity you should be aiming for involves taking a sample into your hydrometer tube.

Measure this and calibrate for 20 degrees Celsius (or 15 if your hydrometer is calibrated for 15 – the actual difference won't be much).

Put it inside a clean, sanitised stubby or similar vessel. Put some glad wrap and a rubber band over the opening, place your thumb over this opening and shake the crap out of it. Put it in a warm spot and aim for anything between 22 and 30 degrees. Let it sit for a few days, shaking it about every time you remember. After say three days, pour back into the sampling tube (NOT the fermenter!!). Measure again with the hydrometer. Has it dropped at all? Is it in the region of your expected FG or does it look like it might have some way to go?

Whatever the answer is, I recommend popping it back into the stubby and repeating the process. If, after the second time it's remained the same and that region is within the expected range then that is your final gravity and where your brew should be before you bottle. If it drops the second time, repeat until you get to the expected range or until you are convinced it won't go any further.***

This may seem like a pain and that it will take forever to get your brew ready. Fair enough – this I understand. However stitches in your eye versus good, clean beer in the bottle is an easy decision to make. Buy another fermenter, get a second brew going, save the children.

WHAT TO DO IF THE BREW IS STALLED

Now if your brew really is stalled, there are a number of things you can do. Most/all of these things you can do in conjunction with the fast ferment test explained above so it won't take as long as this explanation seems to suggest.

1. Gently swirl the fermenter. This may be enough to kick the lazy yeast back into suspension. Stirring gently is another option – if you do be clean and sanitary. Do not go crazy or try and aerate – this will probably make the yeast work but will possibly (likely) oxidise the beer and make it taste bad. Refer to the taste test suggested below with the sample in the stubby if you don't believe me.

2. Allow the fermenter to gently warm a little. Most bad esters etc from high ferment temps will occur in the earlier stage of fermentation so don't be afraid to push an ale up to 22 or even a touch higher (still wouldn't recommend ridiculously high, brew dependent) and a lager yeast up to low end ale temps (eg. 16-18) AT THIS LATE STAGE OF FERMENT.

After steps 1 and 2, WAIT a couple of days, then check gravity to see if it's moved. If it's moved then just let it do its thing.

3. Rack the brew. This means transferring, gently, with a hose, to another vessel (such as another fermenter). This can kick yeast back to life. There are other reasons to rack (and many not to) so do your research first.

WAIT

4. Pitch new yeast. This is not necessarily as simple as just sprinkling a new yeast on top. You may have success doing this but I would recommend making an active starter. If you use dried yeast it is generally not suggested that you need to, or should make a starter. However with stalled ferments it's a slightly different story. You have a much better chance of kicking off the ferment if the yeast is up and raring to go. There are many articles and references on making a starter. Remember it should be active. You are not growing or stepping up yeast, merely pitching yeast that is alive and hungry.

WAIT

So to summarise:

1. Make sure the ferment is really stalled

2. Swirl and/or warm gently

3. Wait

4. Rack

5. Wait.

6. Pitch active new yeast

7. Wait

*I'm going to assume that using a hydrometer correctly is par for the course; if you are reading this and you don't currently own one then I highly recommend you spend the $12-15 and save yourself some possible dramas later.

**That I know of

*** Slightly off topic but if you want to know why you should treat beer gently after fermentation, have a sip of this sample. Be prepared to screw up your face.