Brewing at 35C-40C

[Paulus]

Hi all,

I am hoping to get a firm idea of what is causing some off tastes in my last few (kit) brews. I started with a Brewferm special Belgi in May and controlled the temperature of the primary fermentation OK. I bottled it and left it 3 weeks and it was pretty good (slightly off but only if I thought about it).
My next attempt was a Mangrove Jack lager where the yeast did not take and I had no spare so had to chuck it.
The 3rd attempt was a Muntons Primium Lager. This one fermented and was bottled. I left it in a dark cupboard for 2 weeks but had a really strong off flavour (bitter). The temperature in the area was getting past 35C.
I have done another Special Belgi. It has a good strong flavour on bottling and I kept it in a cooled (21C) chamber for a week before moving it to the same storage location as the previous one. This had a softer off taste than the lager but was definitely there.

Is it leaving the bottles to 2nd ferment at high temperatures that causes the off flavour? I believe I am sterilising everything OK and when tasted before bottling the beer seems OK.

I would have thought that the 2nd ferment would be over within a week?

Any help would be appreciated, once I can get these kits coming out fine I plan to move on to brewing from grains. Just looking to get the fermentation and bottling right parts right before I invest moving forward.

 

[Graz]

Potentially you could be seeing yeast autolysis caused by high temperatures or large temperature swings but by all accounts if this happens the flavors generated are pretty nasty. That said with the small amount of yeast cells in each bottle the impact could be less so maybe.

Could just be your water though if you still get off tastes when bottles are kept at more sensible temperatures. Could try a brew using supermarket mineral water and see if that is better?

I only brew kits and the majority of mine turn out well, no off flavors. I do control the temperature during the primary. I also keg and force carbonate so no secondary fermentation excepting a few bottles to deal with the size difference between a 23L kit and a 19L corny. The bottled stuff is generally good though. Might just be lucky that we have good water in Worcester.

 

[xozzx]

Is it leaving the bottles to 2nd ferment at high temperatures that causes the off flavour?

you could try leaving some bottles in a cooler place (fridge, etc) to see if any difference compared to the ones in high temp.

You could also try replacing the kit yeast with kviek yeast which can cope with temps upto about 40C without any off flavours

 

[Paulus]

Thanks for the replies.

I am using a Muntons Gold yeast on the latest Ale. 1st ferment was about 20-21C and I kept the primed bottles in an insulated & cooled bag (20C) for a week so far. There seems to be little gas but the taste is OK.

The water I use is filtered from the tap. It tastes OK when drunk direct and at 30C. I put this in containers in the fridge to get the temperature of the water down to about 7-8C before adding to the LME of the kit with boiled water. Other wise I'd have to leave the wort a day to cool down before pitching the yeast. The yeast is hydrated with a small amount of DME for about 20mins in 25C water.

I have removed a few bottles now and will leave them a week at ambient (about 32C) while the rest stay at 20C for the same time.

I will try and get some kviek yeast (thanks for the info on that) for the next brew which will be a Helles.

 

[xozzx]

I kept the primed bottles in an insulated & cooled bag (20C) for a week so far. There seems to be little gas but the taste is OK.

Are you adding priming sugar to the bottles?
If there is not a lot of gas then it is unlikely to be infection as you will most likely get gushers if its infected.

The yeast is hydrated with a small amount of DME for about 20mins in 25C water.

This is not really necessary, I would just pitch the yeast directly onto the wort. Everyone has their own ways of doing things so upto you but worth watching this video from Lallemand.

 

[Paulus]

Are you adding priming sugar to the bottles?

I boil the dextrose in 200ml of water and add it to the bottling bucket before siphoning in the beer from the fermenter from there it gets siphoned to the bottles. I use flip top bottles, mainly recycled Grolsch.
The instructions call for 1/2tsp/pint. For the 40 pints I use 96g of dextrose so should be OK. I just think the bottling sugar level in the instructions is a bit low really (Muntons Nut Brown Ale, though common to the whole connoisseurs range).
All the bottles, equipment and bucket are sterilised before use.

 

[Birdsnestbrewery]

Not sure how it varies for dextrose but I generally use about 3-4g of ordinary table sugar per 500ml bottle. I dissolve in boiled water and add directly to the bottles with a syringe. Avoids) around with a bottling bucket.
Regarding the temperature were you saying that you were able to keep the temperature low (20-ish) for the primary fermentation, ie for about a week, and the higher temperature was only after bottling? Or did it rise prior to bottling?
In any case I would keep some bottles in a coolish place if possible for a few more weeks and they will likely improve.

 

[xozzx]

I havent bottle carbed for a long time but pretty sure I used 100g sugar per batch and did as Paulus is doing, using a bottling bucket. Pros and cons to both ways but I dont think this is what is causing your issue.

I guess you are having very hot weather at the moment? My thinking is that the yeast is your problem... it needs to be kept refrigerated as it will not last long (few weeks) at room temperature, at 35C it will be far shorter. Even if you refrigerate as soon as you get it, has it been in the mail? shop shelves for weeks? kept in the kit waiting to brew it? A poor performing yeast will give you off flavours and take a long time to properly carbonate your bottles, I would try getting separate yeasts which havent been stored in the box with the kit but kept refrigerated as much as possible, kviek would be worth trying but any other non kit yeast is also worth a shot.

 

[xozzx]

you could get another bucket and try 2 kits at once, the kviek loves temps around 35C so could do one outside of your cooled chamber. It should be done in a week, bottled then ready to drink a week later.

 

[Paulus]

Regarding the temperature were you saying that you were able to keep the temperature low (20-ish) for the primary fermentation, ie for about a week, and the higher temperature was only after bottling? Or did it rise prior to bottling?

The 1st fermentation was at 20Cish for about a week. After that I bottled and left the full bottles in a cupboard which is somewhere between 28-35C all the time.

A poor performing yeast will give you off flavours and take a long time to properly carbonate your bottles, I would try getting separate yeasts which havent been stored in the box with the kit but kept refrigerated as much as possible, kviek would be worth trying but any other non kit yeast is also worth a shot.

The first fermentation went quite quick so I think the packaged yeast (Muntons Gold bought separately) was OK. I'm pretty sure it is just the temperature on bottle fermenting.

I have a batch now which I have left in the fermentation bag (Cool Brewing Bag - Insulated bag) with cooling for a week now. I have taken out 2 bottles (after 5 days in the cooler) and left them in the usual cupboard. This weekend I'll see how one of them is then try the other a week later. Once the 2nd fermentation is over I am hoping the heat is not an issue so I can store them out of the bag.

Not too sure about using Kviek as, (from what I have read) it gives an orange/lemon flavour, which is better than the bitter taste I have been getting but I'm still hoping to get a standard (lager or Ale flavour).

The temperature gets to about 30C in May here and stays above that until late October. So if I want to brew something I'm going to have to sort out where I need to change my process and then move on to all grain.

Thanks to everyone commenting, really good to get the opinion of people with more experience than me.

 

[Paulus]

I have tried the last brew throughout the last 10 days after bottling and found, that after moving a bottle to a non temperature controlled cupboard, after 8 days in 23C conditions there were no off flavours.
From now on I will be keeping the beers at 22C for 2 weeks after bottling before putting them in ambient storage.

Thanks for everyone's input, I appreciate your help.

 

[MashBag]

If your ambient temp is 30c. That's too hot for brewing. Lager likes to ferment cooler than ale, but there are some new yeasts that change that.

Get both your primary and secondary fermentation done in or around 20c.

Have you considered a farmhouse beer, with kveik yeast?

 

[dmtaylor]

Lager yeasts won't ferment very well at high temperatures. Quit using lager yeasts unless you can keep the temperature down to something reasonable.

You're a perfect candidate to be using kveik yeasts. I don't like them, but if I was fermenting at 35-40C on a regular basis, it would be just about the only choice.

 

[Paulus]

Hi MashBag, ambient goes from 15C in winter to 45C in summer. I have insulated and cooled bags to ferment in and am now using them to continue the 2nd fermentation for upto 2 weeks. This seems to work OK.

I can keep a wort down to about 20C when the temperature is in the 40s. However, it has to start at that temperature as my cooling kit is pretty basic.

I am currently just brewing from kits. When I get a process I can rely on I will move on to all grain to make the wort.

I will be doing a few more kits with this process just to make sure it is repeatable and go through a winter here brewing to make sure it is an all year round option.

I have not heard of a farmhouse beer before so will look into it.

 

[Paulus]

Hi dmtaylor,

the 1st fermentation I can cool to 20C with the rig I have. The problem I had is the 2nd fermentation. I wasn't sure that bottle fermentation (with 100g of sugar) would cause the high level of off taste I was experiencing.
I have found that it was the case and that I need to keep the beer temp down to 23 for 2 weeks after bottling.