Fermenting At Reduced Volume And Then Topping Up?

[beerandgarden]

I'm doing a toucan Coopers Stout & Dark Ale and I know this will blow over big time because I've done the stout on it's own and had it blow out through the airlock resulting in a bit of a mess (and some lost beer). I read a tip on the Coopers website forum - make it up to 15L instead of the usual 23L and then top it up with water after the active fermentation is over. Just wondering if anyone here has any opinion on this approach? Any downsides to this? Was wondering if the higher SG would stress the yeast?

 

[ekul]

Be careful with the water you add to top up as it may introduce oxidation.

Maybe you could try a blow off tube? Pull out the airlock and stick a tube in there that is 1m long. Put the other end of the tube in a plastic bottle, put some sanitiser in there. Any escapees will be safely trapped in the bottle.

 

[Truman42]

I often top up with water to reduce my Sg to target before pitching my yeast but never heard of adding water at end of fermentation.

Especially 8 litres to a 15 litre batch. Wouldnt this just water down your beer considerably to the point it was like a beer and water Shandy??

 

[QldKev]

I don't think watering it down would cause issues being like a shandy, you are just watering it down to the correct malt+hop to water ratio, ie specific gravity. If you got a 23L batch and added extra water you would result in a batch under gravity, and get a shandy brew.

As ekul pointed out I would be more concerned with the introduction of oxygen late into the ferment and oxidize it. Even if you was really careful not to splash, the water you would be added would already be oxygenated. As ekul said, get yourself a decent blow of tube, also find a larger sized fermentor (if your using the Bunnings 25L canoe drum they now have a 30L square version) and if possible during the early stages of fermenting keep the temp down a bit to minimize the head space required.

QldKev

 

[adam]

i have done this without any problems. But I top up to 23 litres just as the krausen starts dropping back - ie, while fermentation is still going (in its last stage)

 

[Amber Fluid]

I know people who do this everytime they brew and they don't have any problems. Some will rack the water to the brew via a sanitised siphon as they are a bit paranoid of oxidation and others will gently pour the water in.

I can't see how it would water down your brew as you are only putting in water that would be in there normally anyway. All the fermentables and hops remain the same and beers largest ingredient is water.

 

[Truman42]

I know people who do this everytime they brew and they don't have any problems. Some will rack the water to the brew via a sanitised siphon as they are a bit paranoid of oxidation and others will gently pour the water in.

I can't see how it would water down your brew as you are only putting in water that would be in there normally anyway. All the fermentables and hops remain the same and beers largest ingredient is water.

Cool..I didnt know that, so you can add your water before or after fermenting to either reduce your start SG or your FG to target.

 

[beerandgarden]

As ekul said, get yourself a decent blow of tube, also find a larger sized fermentor (if your using the Bunnings 25L canoe drum they now have a 30L square version) and if possible during the early stages of fermenting keep the temp down a bit to minimize the head space required.

My fermenter is already a 30L one. This is what happened with a single can of Coopers Stout, made up to 23L with 1kg DME and fermented at 20C:

So I'm expecting even more krausen with this toucan. Also this fermenter has one of those plastic airlocks stuck into a small black grommet so not sure if I can use a blow off tube with that. I don't think I have any hose narrow enough to fit in that little hole. From pictures of blow off tubes I've seen, they tend to be fairly wide diameter, so even if I found a narrow enough tube, it may not be suitable for use as a blow off tube.

 

[beerandgarden]

I know people who do this everytime they brew and they don't have any problems. Some will rack the water to the brew via a sanitised siphon as they are a bit paranoid of oxidation and others will gently pour the water in.

I can't see how it would water down your brew as you are only putting in water that would be in there normally anyway. All the fermentables and hops remain the same and beers largest ingredient is water.

I would expect that if you add the water early enough oxidation would actually be a good thing rather than a problem since the yeast are still busy fermenting and would benefit from the oxygen - but that's just a guess and I could be wrong. I think my main concern is stressing the yeast with a higher gravity and then perhaps the dilution might have a negative effect on their performance.

I think I'll give it a try anyway, maybe make it 18L instead of 15L and then add 5L water plus the .5kg brown sugar that's going into this recipe.

 

[angus_grant]

From my reading you might run the risk of oxidising your beer by introducing oxygenated water during fermentation and you run the risk of introducing infections. You could boil the water before adding to the fermenter and solve both potential issues. If your fermentation is going that strongly, I would think any other yeast or bacteria would find it hard to compete against the beer yeast, but still something to think about. No-one wants to spoil a batch of precious beer. :'(

I seem to recall something from a book somewhere about possible shock to the yeast by drastically altering it's surroundings. You would be altering the specific gravity and possibly the pH levels of your liquids in the fermenter by introducing that much water.

All this being said, give it a whirl and see what happens. The worst thing that can happen is that you ruin a container of water, malt, and sugar. Most importantly, report back so we can learn from your experience.

 

[Amber Fluid]

Cool..I didnt know that, so you can add your water before or after fermenting to either reduce your start SG or your FG to target.

I believe they add the water BEFORE fermentation has completely finished but after the krausen collapses. Usually after about 3 days. I'll ask tonight when I finish work and let you know.

Edit: I also just found THIS (check step 3 & 5)

 

[stux]

iirc, on Brewstrong they discussed this. Tasty McDowel (or whatever) adds boiled/cooled carbonated water post-ferment into the kegs.

I think the carbonation helps to deoxygenate the water.

http://www.byo.com/stories/techniques/arti...lume-techniques

 

[beerandgarden]

Just an update on this - I brewed it on Saturday night and made it up to 18L. The fermentation was very vigirous. I got some foam in the airlock but none came out, so looks like 18L is just about the right volume to start with. Today, day 3, krausen has dropped and airlock activity slowed so I added the remaining 5L water plus 500g of brown sugar. I boiled 1.5L to dissolve and sanitise the sugar then added 3.5L cold tap water (to save me having to cool it) to the pot and poured it into the fermenter. The foam rose as I poured it in so hopefully I'm not too premature adding it but I'll keep an eye on it and let you know what happens.