How cold can us-05 reasonably go?

[Sadu]

Quick question.

I have been having problems with everything over about 6.5% coming out with a boozy hot alcohol taste, I'm pretty sick of dealing with it.

I'm brewing a 6.7% American amber ale using us-05 tonight. Normally I'd ferment at 64f but I'm thinking of going cooler to really rule out high temperature as the cause of the problem. I have a temp controller and can maintain whatever temp I need to.

How low can us-05 go before running into fermentation problems / weird flavours etc.

I was thinking of trying 60f or is that getting into danger territory?

 

[porterpounder]

If you pitch enough yeast it will be fine, but if you're fermenting at an accurate 64 F, it's very unlikely those flavors are coming from the fermentation temp. What's your mash program and do you control your sparge temp/pH well?

 

[Sadu]

I had no idea that off-flavour could come from mashing, hence the focus on fermentation temperature. I'd be interested to know of any links that talk about mashing problems causing warm alcohol flavours, generally everyone says it's from fermenting too high.

Except I don't think that I'm fermenting too high, since the flavour is present in lagers as well as ales and I know the temps were good on those brew. But I want to ferment this 6.7% us-05 Amber at low ale temps to rule fermentation temps out of the equation.

As for mashing - I do a single infusion BIAB mash for 60-90 mins at the temp set by the recipe. I sparge at 170 and I'm careful about maintaining good mash/sparge temps (unless my thermometer is out, haven't ruled that out yet).
I don't control my mash ph at all - my last foray into water chemistry ended badly, but I just had some calibration solution arrive today so next batch I'll be able to get a ph reading during the mash and see where that sits.

In the meantime I'm putting out some real nice normal-gravity brews. All the 5-6% abv stuff is real nice, but anything higher has the hot alcohol flavour.

 

[porterpounder]

It's not that mashing can cause high alcohols, but astringency from excessive tannins can cause the perception of hotness in the finish and harshness like that.

 

[ryanryates]

Fermenting in the 62-66 range should provide a clean fermentation. As porterpounder mentioned, ph is an important factor to control during the mash/sparge. I would also venture to guess that your been may be a little green if you are tasting hot alcohols after fermentation. Anything I brew over 6-7% I find needs some time to age before consuming. You might try waiting 4-6 weeks and see how the flavors change.

 

[oujens]

A couple questions:

How are you measuring fermentation temp? Is there a probe on the vessel to control temp?

How much yeast are you pitching? for your stronger beers, do you need to pitch more yeast?

If your lighter beers are coming out better than your stronger beers, it seems you might not be pitching enough yeast. Some people say fermenting US-05 at the low end can cause peachy esters. I think 65-68F is about the recommended range. That is where I have had success. I think I would confirm that your fermentation temps are accurate and double check with an online calculator that enough yeast is being used.

 

[Sadu]

A couple questions:

How are you measuring fermentation temp? Is there a probe on the vessel to control temp?

How much yeast are you pitching? for your stronger beers, do you need to pitch more yeast?

If your lighter beers are coming out better than your stronger beers, it seems you might not be pitching enough yeast. Some people say fermenting US-05 at the low end can cause peachy esters. I think 65-68F is about the recommended range. That is where I have had success. I think I would confirm that your fermentation temps are accurate and double check with an online calculator that enough yeast is being used.

I use a probe in the beer to measure the temperature, temp controller is able to heat and cool as required so I think this process is good. Have had some issues with pumps getting blocked but temps don't stray far from the target.

In terms of yeast I feel my pitching practices are solid. I almost always wake up to krausen on the brew and airlock activity the next morning. I always pitch from slurry that is either fresh from another batch or build a starter from clean yeast in the fridge. Always do a vitality starter on the day if not a proper starter, always use a calculator and record notes on what gets pitched.

For example this 1 gallon American amber I pitched 90ml of 4 day old unwashed slurry in the fridge from the last batch, with a 600ml vitality starter taken from the start of the boil.

 

[Sadu]

It's not that mashing can cause high alcohols, but astringency from excessive tannins can cause the perception of hotness in the finish and harshness like that.

This does sound like the area I need to look at next, and I now have the means to measure pH for the next batch which will be interesting. Water chemistry has been a hard learning curve for me since the water reports where I live aren't affordable. I thought I'd experiment with adding small amounts of sour malt to see what happened - what happened is that I wrecked at least 2 batches

I'm a 1 gallon brewer and brew every week so between brewing something and detecting a problem there can be several batches already in the pipeline with the same problem.

The good news is that I do have a variety of repeatable recipes that are coming out great in between the not-so-great ones - porter, IPA, APA, Cream ale, Blond ale, Helles - all fine. It seems that my water is acceptable without any adjustment for these styles at least.

 

[kh54s10]

I don't think temperature is your problem. It seem like you have a good handle on that. Have you tried a different water source? Even with some adjustments maybe the chemistry to start with is not good for the styles you brew.

What temperature do you use for the mash? Maybe you are sensitive to dry beers, try a little higher for a slightly sweeter beer.

The other possibility is that you are just sensitive to alcohol and will have to stick to lower gravity brews.

I would stick to the mid sixties with US05.

 

[dstockwell]

Except I don't think that I'm fermenting too high, since the flavour is present in lagers as well as ales and I know the temps were good on those brew.

Well this does sound like some other area is the problem. Since lagers are fermented cooler than ales, and the flavor is present in both, something else must be the problem..

 

[seabass07]

How's the body of the beers? Have you checked fg? I'm wondering if the hotness is due to a lower temp sacc rest from your thermometer being off leading to a thinner beer with more alcohol than you expected.

 

[Sadu]

How's the body of the beers? Have you checked fg? I'm wondering if the hotness is due to a lower temp sacc rest from your thermometer being off leading to a thinner beer with more alcohol than you expected.

Yes that is something else that is compounding the issue. Most brews finish low, for example a bohemian pilsner finished at 1.009 which is 5 points lower than designed. Combined with great efficiency and the recipe being at the top end of the style anyway, the result is a 6.7% pilsner. I would expect this to take a while to mellow out anyway, at the moment its lagering in primary in the fridge. Also I think Jamil is not joking when he says this is a hard style to brew - you do taste every little mistake.

I upped the mash temp on this latest test batch by 2c to counter the thermometer being possibly out. So full body profile instead of medium body as called for by the recipe.

 

[casualbrewer]

Would pitch a different yeast like notty if you wanted to rule out that yeast....

 

[seabass07]

Yes that is something else that is compounding the issue. Most brews finish low, for example a bohemian pilsner finished at 1.009 which is 5 points lower than designed. Combined with great efficiency and the recipe being at the top end of the style anyway, the result is a 6.7% pilsner. I would expect this to take a while to mellow out anyway, at the moment its lagering in primary in the fridge. Also I think Jamil is not joking when he says this is a hard style to brew - you do taste every little mistake.

I upped the mash temp on this latest test batch by 2c to counter the thermometer being possibly out. So full body profile instead of medium body as called for by the recipe.

That might be the majority of your problem. A super dry nearly 7% pilsner would be fairly hot. Can you just check your thermometer? Dip it in boiling water and ice water.

 

[Denny]

Quick question.

I have been having problems with everything over about 6.5% coming out with a boozy hot alcohol taste, I'm pretty sick of dealing with it.

I'm brewing a 6.7% American amber ale using us-05 tonight. Normally I'd ferment at 64f but I'm thinking of going cooler to really rule out high temperature as the cause of the problem. I have a temp controller and can maintain whatever temp I need to.

How low can us-05 go before running into fermentation problems / weird flavours etc.

I was thinking of trying 60f or is that getting into danger territory?

I've run it at 52F without problems.