Bottling Day #1 - Disastrous fermentation??

[boosy]

So after my uncertainty about the fermentation of my first brew, I did a second brew the following week. A week later, today, I bottled both, so the first one had been in the FV 2 weeks, and the other one 1 week. I took readings on my refractometer and they have confused the hell out of me.

For brew #1 it looks like I've gone from a pre-boil gravity of 16 brix (1.066) to 13.8 brix (1.056) pre-bottling. I forgot to take a post-boil reading but I'm guessing around 1.088. By anyone's measure, that's not a good fermentation. It makes no sense to me though, because the beer both tastes and smells heavily alcoholic to me. I'm wondering of I can be getting my readings wrong somehow? Anyway I primed it with 27g of sugar into 7l of beer and got on with the bottling.

If the readings are right and I've still got such a high gravity, does that mean I'm going to be getting exploding bottles? I've got them sealed in a thick cardboard box with a plastic sheet round it to catch any liquid that may escape if things explode. I assume that wrapped up like that there's going to be no danger from any exploding bottles? Could the coconut in the FV have anything to do with me getting a much higher reading than I expected?

For brew #2 it looks like I've gone from a post-boil gravity of 16 brix (1.066) to 8 brix (1.032) pre-bottling BUT that measurement was taken after I added the priming sugar, so that would have bumped it up a bit I suppose. I was looking for 1.016. For this one I primed it with 37g of sugar into 8.3l of beer. I'm not so worried about this one.

Anyways the bottling itself went relatively to plan. With the coconut one I filtered it through a muslin bag on the way into the bottling bucket to keep out the coconut and the sediment. That seemed to work pretty well, leaving me with a nice clear beer. that filtering won't affect the carbonation in the bottle will it?

So many questions. It's been great fun so far though and I can't wait to get one of these drunk in august!

[Parva]

If I were you I would get yourself a hydrometer. I too use a refractometer but tend to use it to determine whether fermentation has stopped before taking a final gravity reading with the hydrometer. Refractometers are a handy piece of kit for quickly determining a close figure but I always use a hydrometer to determine start and final gravity. I'm not really sure how you can rescue the situation you're in now but those are some very wild figures you have.

[boosy]

That's what others have been saying also so yeah I think I'll get one of those. I initially went for the refractometer because from reading various things I got the impression that they were better for a few reasons. Given that everyone has been saying to get a hydrometer now, I suppose I must have misunderstood about the benefits of a refractometer. They seem essentially useless given that everyone's saying to use a hydrometer. What's the point in having one?

[Andy__]

I dont have a refractometer, but if it helps I was listening to a basic brewing podcast a while ago. They said that it will give you your starting gravity easily at any temperature, but as alcohol is created it throws out any future readings. sorry this is a bit vague. Anyway have a look at the podcasts on itunes for a better description.

[Parva]

A refractometer is a useful piece of kit for some things but it doesn't replace the trusty hydrometer. The beauty of the refractometer is that it only requires a teaspoon or less of wort to get a reading wheras you'll likely need to lose 100ml of wort or more for a hydrometer measurement. They also don't suffer so badly with temperature correction as the sample is so small in comparison to the body of the refractometer that the sample is within range by the time 30 seconds has elapsed unlike a hydrometer where 100+ ml's could take 10-20 minutes to drop to 20c.

This is particularly handy for people that fly-sparge as they can get a good idea quickly as to how low the gravity has dropped. This too can be done with a hydrometer but you also need to make temperature corrections etc so the refractometer is particularly good for taking readings fast without needing to make temperature corrections etc.

Having said all of that, I rely on my trusty hydrometer for starting and final gravity calculations. I use the refractometer for inbetween readings which means that I can get a good idea of where the gravity is currently but only need a teaspoon of wort to do so and not a trial jar full! I would always advise anyone to get a true hydrometer reading prior to fermentation and at least one at the end of fermentation and the refractometer can be used for all stages inbetween to determine how far fermentation has progressed using only a teaspoon of wort rather than a trial jar full.

Note also that the odd air bubble that gets trapped between the lens and the clear cover can throw the readings wildly in a refractometer! Get yourself a hydrometer and use that as the first point of reference, the refractometer is a useful tool and I wouldn't throw it away just yet.

[leewink]

I dont have a refrac. but a hydrometer too.

I dont determine fermentation end with it, as I find 4-5 days in primary is enough for me, to then decant to secondary. (this because I use yeast vit and servomyces to speed the ferment up aswell as finish it too)

My hydro is purely used for start SG and end SG and thats it, I too have only done about 5 or 6 brews, but I keep it simple, and it works for me.

Cheers, lee

[boosy]

Ok, hydrometer it is! I shall use it for the important measurements and the refractometer for the rest.

I need to not use it too much because I'm only getting just under 8l out of my brews (aiming for 10) so need to conserve what I can. My 90 minute boil seems to take me from ~14l to ~8l. Seems like a wild amount of loss but it's happened both times. Any thoughts as to why I might be losing so much volume? Is that normal?

[steve_flack]

For brew #2 it looks like I've gone from a post-boil gravity of 16 brix (1.066) to 8 brix (1.032) pre-bottling BUT that measurement was taken after I added the priming sugar, so that would have bumped it up a bit I suppose. I was looking for 1.016. For this one I primed it with 37g of sugar into 8.3l of beer. I'm not so worried about this one.

8 brix in a fermenting beer IS NOT 1.032. It's a lot less. The alcohol in a beer makes the gravity lower as alcohol is less dense than water. A refractometer can only be used directly like this for wort not beer that has been or is fermenting. There is a formula for calculating the gravity of fermented beer from the brix but it's very complicated but brewing applications often include it. In your case the 8 brix is actually meaning it's 1.010.

For the first beer, assuming an OG of 1.088 a brix of 13.8 would mean the gravity is now 1.035.

For these formulas you need both the OG and the current brix to measured accurately as the formulas are very susceptible to small errors in either producing large variations in the calculated gravity.

[boosy]

Hey, thanks so much for that info! I'm not so worried now, hopefully explosions aren't coming my way. I need to read up a bit more on that clearly. I don't think either of my iPhone brew apps have any brix support at the mo.

For the 1.010 one: I was looking for 1.016, does that mean I should have ended the fermentation sooner? I assumed I should just leave it till it finished (I gave it 9 days)

For the 1.035, that's still way above my target but hey, it was my first beer and I know I screwed up a bit with the yeast so I'm not hugely surprised

Thanks again!!

[cosy101]

wow strong beer all round.1066? thought that figure was only used by school boys......... Battle of Hastings?

[dave-o]

Those are pretty high OGs. What yeast did you use?

[steve_flack]

I don't think either of my iPhone brew apps have any brix support at the mo.

Mine does

http://itunes.apple.com/app/brewmath/id294445180?mt=8

[boosy]

Those are pretty high OGs. What yeast did you use?

For the higher gravity one I used Danstar Munich Wheat which is meant to be ok up to 10%. I also chucked in a pack of Nottingham after about 3 days cos I wasn't sure it was fermenting.

[boosy]

I don't think either of my iPhone brew apps have any brix support at the mo.

Mine does

http://itunes.apple.com/app/brewmath/id294445180?mt=8

Interesting. I've already bought two apps (BrewPal and iBrewMaster), both of which I like in their own way and dislike in other ways. I'm reluctant to buy another though. I'll look more into it.

[196osh]

Re the lower than expected gravity, don't worry about it. It happens, the beer will taste a ok, just be a bit thinner and the abv will be higher.