Temperature and brew activity

[ericmark]

I only use kits. I have noted between 18 degs C and 24 degs C the activity changes measured with stick on thermometer however drop to 16 degs C and normally activity near stops. In early stages a simple body warmer on the fermentor will keep the temperature high enough to ensure it continues to ferment but as it reaches the final stages often I need to use a demo heating tile 18W to keep brew above the 16 degs to get it from 1.012 to 1.006 s.g.

However every round and again I get the odd brew which does not seem to follow these parameters. I have one at the moment, it is been a week in fermentor, and down to 16 degs, and still very active. Not a problem but want to understand why. Use Young's and BrewMaster kits and typically they stay two to three weeks in fermentor and even when two brews running at same time the total time in fermentors can vary by a week. Did a BrewMaster Mild and week latter started Young's Harvest Mild and both ready to bottle at the same time.

I am sure variation is due to temperatures at different points in the process, but this is where in the process that I get stuck with. No data logger to know exactly what the temperatures were, and it would seem from these variations that temperature at start, middle, and end of process, have different effects. At around 2 weeks between each brew I am sure in the end I will work out what happens, and when it happens, but sure some one can explain the effect of temperature at different stages.

I had decided I would wait for winter before doing a Lager as had read about Lagering process, and how needed to finish off cool. However kit instructions for Lager are exactly the same as for Bitter, Mild, and Heavy which is rather confusing.

My aim is after set time to bottle one brew and then transfer next brew into the cleaned out fermentor to remove sediment so when it is bottled there is less sediment in the bottles. In the main this works well but when a brew stalls it results in late transfer of next brew. If transfer is late then too much sediment is removed, and beer really slows down in final stage. So trying to understand varying time so I can get gap between starting brews correct. Started at 7 days between them, but now thinking should extend to 10 days between starting brews, transferring after 7 days, so leaving fermentor empty for 3 days before starting next. Aim is to stop brewing in Summer as last Summer it got too hot. Hence brewing so much in Winter, plus also stopped over Christmas which put a dent in my stock.

 

[rpt]

Most lager kits are supplied with ale yeasts as most people will be fermenting without any form of temperature control and will find it easier to find a suitable spot for ale fermentation temperatures. Some kits do have lager yeast though, and you could also use a proper lager yeast that you've bought separately.

 

[Fil]

For a novice brewer you have Very keen observation skills, You might find the Yeast book by chris white and others a good read..

afaik the yeast are going to generate a bit of heat thru activity and early on in a food rich environment they thrive closer to the end of the ferementation the only food left is the more complex sugars which need a bit of breaking down into smaller chunks for the yeast to digest, (yeah im paraphrasing and am no scientist) so activity slows as does the side effect of heat..

the lager kit you have probably arrived with an ale yeast, you can get a real lager yeast from your lhbs or one online, which will ferment at a lower temps.. that slight mod to the kit should improve it, i say should cos i dont know i have a coopers lager kit i brewed with lager yeast and did the weeks at 0-1C maturing in the keg now.. time will tell..

 

[ericmark]

While writing a thank you to you both I had a thought. Maybe all to do with temperature at start? I mix hot and cold water out of the tap and wait until between 18 and 22 degs before adding the yeast, but it could be mixed at anywhere between 16 and 28 degs then left to cool or heat until within the limits.

I stand to be corrected but I am lead to understand fish die in the summer as the water has not got enough oxygen in it so me mixing everything at 16 degs will leave the mix with more oxygen than mixing at 28 degs and I have never re-aerated before adding yeast. A screw cap with air lock using an electrical stuffing gland is put on the fermentor so once yeast added only oxygen in the mix and the couple of inches of air above mix is available to yeast.

So is the difference in how fast all to do with temperature at which everything is mixed up the thick treacle like concentrate and sugar does take some mixing I will often half fill first and spend ages sloshing it around to get it mixed up but the temperate at which I have mixed I have not recorded so no idea which got mixed at what temperature.

So question is should I aerate brew before adding yeast, or at least mix yeast before starting on beer kit with warm water, and let it re-hydrate before adding to beer? If so should I add a little sugar to yeast to help it get started?

I hope I have found it now I wait to see your reply. Yours Eric

 

[Fil]

aerate at pitching temp, for the best possible ferment the optimum population of yeast can be built up in a starter from dry yeast. 100g of dme in 1l will give u a 1040 gravity starter liquor.

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A good read
http://www.amazon.co.uk/Yeast-Practical ... 0937381969 :

 

[ericmark]

Thanks it seems I am doomed to learn more. I am an engineer. I must also take a look at the critters not sure how powerful microscope has to be but must give it a go.

 

[rpt]

You don't need a starter with dried yeast but rehydrating before pitching is a good idea.

 

[ericmark]

Thanks I bought another Lager kit and used Young's Lager yeast sitting in garage at 10 degs C crossing fingers and hoping it works. Yeast packet said sprinkle direct onto beer so that's what I did. Not sure if garage or shed is best place but temperature in garage is more stable and slightly warmer so as summer comes may move into shed.

It will be interesting to compare two beers one called Lager but clearly with Ale yeast and other with Lager yeast. However I prefer bitter most of the time so likely this will be like my Ginger Beer and only brought out for visitors.

 

[PaulCa]

Oh boy... when you get to mashing....

 

[ericmark]

Started on Friday 31st Jan 2014 kept at 10 degs C and today 5th Feb 2014 five days on and no sign of activity I'll give it to Friday and if still nothing then I'll move from garage to kitchen and raise the temperature.

 

[rpt]

Have you taken any hydrometer readings? You may find it is actually fermenting.

 

[Fil]

+1 a slight miss in a lid seal will give the co2 a easy exit bypassing any airlock, so no glug isnt proof of a stuck beer.

Tho, i think most lower temp lager brewers will pitch with a fairly big starter built upto 2l+ over a few days.
so it may just be a slow start as the population builds up..


afaik, its not that they wont work for you at higher temps, its more to do with the flavor creation and tolerance at the lower temps that the lager yeasts are selected for.

 

[rpt]

That's a good pointer about pitching temperature. I use S-23 when I do lager and pitch one packet at 20C before lowering to 12C after 24 hours. If I wanted to pitch at 12C I would need 2 packets. Perhaps you have underpitched. The yeast may have a long lag period and get going. Hopefully they won't have created too many off flavours.

 

[ericmark]

I am trying to get my head around all this. The Young's Lager yeast had one instruction (Suitable for 25 litres sprinkle on top of beer) and using the Geordie Lager kit instructions clearly does not produce true Lager.

The lid does not leak I use Vaseline on seal and air lock is in an electrical stuffing gland IP67 so that will not leak either I will admit with the old rubber bung there was a problem with leaking. In this wind in my garage the bubble does move back and to but does not bubble and there is no sign of the scum normally formed when a brew starts. The garage is part of the house so although no direct heating it does get some through the walls so has sat are reasonable consent 10 degs C.

So my options are:-
1) Give it more time.
2) Bring into kitchen let it get started and then take back out to garage.
3) Bring into kitchen and add kit yeast and brew like an ale.

What I don't know will if I let it reach 20 degs in kitchen that mess up the Lager yeast? I have loads of stock so in no hurry however clearly if the brewing does not start a sugary mix will be vulnerable to other moulds as well as yeast growing. I am not keen to remove lid as this also could allow in bad bits.

I am open to suggestions both for this brew and future brews.

 

[PaulCa]

I started a lager last week. The yeast (Brewferm) said "12-15C" for the ferment temp.

I started off in the fridge, but when that turned out to be 8*C and after 2-3 days there was zero activity I removed it from the fridge and allowed it to warm to 16C, then back into the fridge and kept it at 16C ish until I seen activity. Then I chilled it back down to 11-14C. It's now day 7 and one demi john has about 3mm of krausen and lots of rising bubbles and the other identical brew has over an inch of mostly floating trub on the top! The CO2 produced by the yeast causes the break material to float for a period, I've seen it before, it will settle when things calm down.

I would try option 2 from your list. You may not want to get them up to 20C room temp as when/if they do kick off you won't be able to cool it fast enough to prevent a hot ferment/off flavours.

I think Young's lager yeast may be a bit rubbish. I found 4 sachets in my ingredients drawer and decided not to use them as they didn't have a target temperature and I couldn't find anything online either. Yours may simply be too cold for them to start up.

 

[PaulCa]

Oh and once you do get it running, try wrapping it in a blanket (in the garage). The heat produced by the yeast may then help you keep it up a few degrees towards 12C.

 

[ericmark]

Thank you. I have decided too heavy to move so much so put a sample underfloor heating tile under the fermentor 18W and wrapped it in body warmer and coat I know it takes around 12 hours to raise the temperature 2 degrees so I will check again tonight likely stick the remote from weather station in the wraps so I can monitor temperature from indoors.

Had a peep inside and small layer of bubbles on the top which unless some gas released would not have likely still been there after 6 days so sure something going on just a bit on the slow side. No krausen yet.

The local brew centre only had Young's Lager yeast so no real option. Morrison's where I got kit does not sell any extras but £7 compared with £12 from local brew centre is just too much differential I would pay a little extra from brew centre but not that much.

Assuming it starts with extra heat then next question will be secondary fermentation. I have with ales transferred to second fermentor after around a week as air lock rate starts to subside. This has reduced the amount of sediment with final bottling and has worked well. However with Lager taking longer don't really want to tie up my fermentor for so long plus weight of moving such a large container and likely will disturb sediment when I move so will need to settle before bottling. So considering using demijohns for secondary fermentation as easier to move, sediment will resettle quicker after move, and not stopping me using fermentor for other brews. I would guess 5 or 6 demijohns easy to move. Any thoughts please.

 

[proost]

PaulCa, a demijohn?
Can I ask what you are making and what is the capacity of the demijohn. I've just started home brewing and like the idea of small batches of lager as I mainly drink bitter.

 

[PaulCa]

PaulCa, a demijohn?
Can I ask what you are making and what is the capacity of the demijohn. I've just started home brewing and like the idea of small batches of lager as I mainly drink bitter.

2 x 5 litre (1 imperial gallon (ish)), clear plastic, PET. On ebay for a few quid each, go to a fiver and they come with airlocks and temp strips.

viewtopic.php?f=36&t=50165

Small batches work fine apparently. I can just about make a 10 litre (about 9 actually) all grain brew with a 12 litre pot. Also I don't need fridge space for a 5 gallon FV! 2 Demi's fit my small beer fridge with room for a bottles.

PET Demi's are fairly cheap, so I got four of them, 2 primary, 2 secondary.

 

[ericmark]

Used my demijohns in the main for wine all glass and for wine need 4.7 litre capacity with some this is to the neck with no room left to allow any gas which is clearly no good others at 4.7 litres leave enough gas to work OK. Most of mine now marked so I keep the larger ones ready to make wine.

As to small batches in the main to start with people buy kits which are designed for 40 pints around 22 litres and the concentrate is very thick. By time I have added sugar and hot water to mix it around 15 pints just could not get that into a demijohn and no real way to ladle out even amounts of concentrate into 5 or 6 demijohns which relate to 40 pints.

However nothing stopping one from making up 40 pints in a bin or other large container and then siphoning into demijohns once all the ingredients are mixed. Do be aware that it takes a lot of mixing the concentrate is very thick and sugar also takes some dissolving I use the can which had the concentrate to add the first bits of hot water into the fermentor to wash the concentrate off sides of the tin. I also put sugar in first to reduce the amount the concentrate sticks to the bottom.

I started with just the fermentor just added concentrate, sugar and water and stuck a bung in the hole in the lid. Left for around 6 weeks and then bottled and it worked well.

However I really had no idea if ready to bottle so just left it well over time adding an air lock and a temperature strip allows you to see when ready to bottle so if around 20 degs C and bubbles less than one a minuet with a good seal then ready to bottle. However getting a good seal is a problem I use an electrical stuffing gland to seal air lock to screw cap of fermentor and to ensure it is really finished I use a hydrometer to confirm ready to bottle.

Using plastic pop bottles helps you can test pressure without opening bottle I have only had one type of beer where there were problems and the beer had to be returned to fermentor that was Coopers Ginger beer which was extremely slow to ferment and I had thought it had stopped but it wasn't all the other kits have worked well.

With this lager at such low temperatures I expect problems I am not following instructions with the kit and I can't really complain if it does not go as expected. With other beers I have noted at around 16 degs C activity nearly stops but reading about Lager it was seem this method of brewing means the beer lasts longer and with slightly different taste. I fancy Lagering a dark beer but before I try with a dark beer want to see how it works with a light one as we would expect out of the pub tap.

With my other hobby photography we say if you have no failures your not trying anything new. Up to date I have only poured one bottle of beer down the sink. It was in an old Bailees Irish Cream bottle and tasted like flavoured water others in same batch were OK. Clearly I had not cleaned bottle well enough. However can be the reverse one of best bottles was in a bottle which had contained orange concentrate and that was lovely although attempts to reproduce the accident failed.

If my Lager works out likely some bottles will still be around in 2 years time as not really a Lager drinker. My problem is gathering together enough bottles. The longer time Lager takes will allow my bottle stock to rise ready for when I start on bitter again.

While I am writing this I have been motoring my Lager temperature rising 40 mins raised 0.3 degs it is going to take a long time.