Tart beer tastes

[TimT]

So my various experiments with doing weird herbal beers are going quite well but I'm getting repeated difficulties with one particular issue: tart beer tastes, especially in my dark brews.

I have two or three ideas as to what may be causing this, but I wanted to get the learned opinions of the Good Burghers of AHB.

1. Hopless beers just taste like this - hops, being a strong spice, mask the tart flavours. Doesn't yeast tend to acidify a brew?

2. Something to do with water pH where I'm living. (Lalor, outer Melbourne).

3. The dark grain itself contributes a lot of tartness. Manticle mentioned a while ago that sometimes he soaks his grains in cold water to remove harsh, bitter flavours? I'd be interested in learning more about this process. (Like, do you mill the grain first, then soak in cold water for half an hour? Would this affect mash efficiency?)

So; what do people think is causing this? And what's a good remedy? My aim with herbal brewing is to make good beers that bring out lots of natural yeast, malt, and herbal flavours, and to use herbs and spices not to mask the other flavours of a brew, but as complements.

 

[GalBrew]

What dark grains are you using? Maybe you could try subbing some huskless or de-husked varieties (there are plenty about these days) and see if it makes a difference?

 

[sponge]

Just in regards to cold-steeping roast malts, just mill and let sit with a couple of L's of water and add the lot to the mash during mashout.

it is now how I add all of my dark malts to my beers.

 

[TimT]

It could be the dark grain, yeah. Mostly it's this chocolate malt I got from my local HBS. Dunno the origin, they just whacked their own label on it. I could ask them.

 

[TimT]

Just in regards to cold-steeping roast malts, just mill and let sit with a couple of L's of water and add the lot to the mash during mashout.

it is now how I add all of my dark malts to my beers.

Ta Sponge.

You mean add the water you steep it in too?

Why during mashout? Is it because they won't benefit from a mash anyway?

 

[Black n Tan]

You mean add the water you steep it in too? Yes

Why during mashout? To maximise the extraction of the sugars Is it because they won't benefit from a mash anyway?Yes and will avoid the dark grain driving the pH of the main mash too low

 

[TimT]

Thanks! Hm, but if you soak to remove tartness won't adding that water to the mash add much of the tartness back in? Sorry if the questions are a little too obvious but I just want to make absolutely sure I get every step of the process right and know why!

 

[manticle]

Not tart like vinegar or sour milk?

Does it appear in brews that have no dark malt (even if it is less apparent)?

Whereabouts on the tongue can you taste it? Front, back, sides? Anything like overstrong/over brewed tea?

The main reason I cold steep roast grains is so I don't overacidify my mash when making stouts and porters. The darker the grain, the more acidic it is. Some brewers add things like chalk to the mash but I don't love the results of chalk, it seems counterintuitive and it is also very insoluble and thus not very effective.

I crush the grain finely, add to a few litres cold water in a clean stainless pot and soak, covered in the fridge overnight.
Come mash time, I slowly heat the pot to about 70 and add at mashout. This way all of the flavour has been extracted but the acidic grains are kept away for most of the mash and the pH will be pretty close to set. Any drop shouldn't affect it too much at that stage.

I made many a great stout and porter before doing this and before I ever worried about water chem - it is a tweak only but I've been very happy with the resulting smoothness.
You can also just add the crushed grains at mashout, hot steep (defeats the purpose a bit I reckon), cold steep less time or strain and add the liquid to boil rather than the lot at MO.

 

[manticle]

Thanks! Hm, but if you soak to remove tartness won't adding that water to the mash add much of the tartness back in? Sorry if the questions are a little too obvious but I just want to make absolutely sure I get every step of the process right and know why!

Roast grains may add astringent notes because of their effect on pH. If the pH is set (buffered by phosphates, etc), adding roast later avoids this. Typing on phone so explanations aren't as thorough as I'd like. Apologies.

 

[TimT]

Thanks for the excellent detailed explanations so far Manticle. I think when you say 'the darker the grain the more acidic it is' you describe my experiences quite well.

These tart flavours don't seem to me to be particularly noticeable with hops because hops have such a powerful taste anyway - and they have an interesting way of complementing and enhancing the malt flavours. But with herbs? Yep, they come through.

Now to the questions:

Not tart like vinegar or sour milk?

I wouldn't describe them like that, no. Maybe - intense fruit tartness?*

Does it appear in brews that have no dark malt (even if it is less apparent)?

Ehrm, sort of. Lighter brews without hops do seem to have a mild sourness. I find it very pleasant, and I think it's just the natural yeast flavours. I've had some commercial wits and saisons with similar flavours - you know, beers where the yeast esters are quite important and tend to dominate over the hops.

It's looking like tartness and acidity from the dark roast grains may be the culprit, maybe in combination with the mineral content of our water. I'll focus on that!

*Note - I made a butter beer, a kind of hot mulled ale, with one of my recent dark brews and the addition of sugar, cloves and ginger in combo with the tart taste made it taste very similar to a mulled cider.

 

[Black n Tan]

If it is the acidity caused by the dark grain, then I don't believe that steeping those grains and adding at mash-out will remove the problem: the acidity will still be there, it is just not there during the main mash. If it is astringency then a cold steep may help, but you are better to find the cause of the astringency. I suspect astringency, because you indicate you still get a bit of it with paler beers. Do you mill your own grain? What system do you have? Do you sparge, how much and what temp? I have cold steeped and found it doesn't contribute the flavour I want. I use Melbourne water and find a few grams (about 4g) of baking soda in my porters and stouts gets me in the right ph mash range. It only lift the sodium content to about 45ppm which is of little concern. Do you do any water adjustments? What % dark grain causes you issues? .

 

[TimT]

Seeing as you, Manticle and I are all in Melbourne's north our water is probably quite similar.

My system is a variation on brew in a bag. I call it brew in a rag I effectively do two mashes, usually around the mid-60s. The second one you might call a sparge, since the purpose is to get any residual sugars to convert and come out of the grain with the help of the enzymes that are still working. Squeeze the bag both times. Might run some hot water through it at this point to get the wort to the required volume and get more sugar/colour out of the grain.

Hand mill the grain, no water adjustments!

The harsh tastes really come out in the dark beers, browns don't seem to be a problem.

Not eager to add soda or chalk to my water (put it down to a combination of squeamishness and laziness) but as this problem is fairly predictable now I may have to look at all possible solutions. If soaking dark grains can help in mash pH, and that can help to maximise the sugar extraction, good, as perhaps that will offset tartness. Maybe it could be astringency from squeezing the bag or from running hot water through the grain? (Could this be a flavour that fades with time? I have some dandelion honey porter that is in the process of ageing; will test that in a few months).

Thanks for all the ongoing help, suggestions, and questions. I'll work it out!

 

[TimT]

So I was just reading this paper, linked on another thread, and it too suggests that dark beers can definitely overacidify due to the percentage of the dark malts and the acidity they bring. It seems, if I read this paper correctly, that the acidity may increase during the sparge. So maybe one thing I could do is 1) add dark grains at mashout 2) either shorten the length of the sparge, or have no sparge at all?

 

[Black n Tan]

Yes dark grain add acidity and could drop the pH of the mash too low and also the pH of the beer affecting flavour. You can cold steep your dark grains and add just the liquor at the end of the boil. It is my understanding that the wort pH drop significantly during the boil (more so than during the mash) and by adding the grains with 10 minutes to go, you MAY limit this drop. Otherwise a touch of bicarb as I have said: it is little effort if it cures the problem.

 

[GalBrew]

Even if no-sparge (which is what BIAB generally is) your dark malts are still going to acidify your mash. If this is what is resulting in a tart taste in your beer then your only options really are to either add something alkaline to the mash or remove the dark grains from the mash. Also have you compared the pH of your finished tart vs non-tart beers to see if it is actually a pH issue?

 

[TimT]

pH test may not be out of the question, just to see what's going on. I will try simple solutions (adding dark malts late in the boil) before proceeding on to the question of additives (bicarb, or similar). Thanks all.

 

[TimT]

So, I have completed a dark brew this morning. Ingredients were simple: equal parts vienna malt and rye malt, with a small bit of chocolate malt to give it colour.

I steeped the dark malt overnight in water in the fridge. Did a long mash at around 64/65 degrees, drained that off, and then did a second mash to get residual sugars out, in plenty of water as I wouldn't be bothering with sparging. Drained that off, and I had enough for the boil.

Added the chocolate malt wort late in the boil, 10 minutes before the end.

So, by avoiding mashing with chocolate malt hopefully I've avoided acidifying the mash. By not sparging, I trust I've avoided adding harsh flavours to the brew. And by adding the chocolate malt 10 minutes before the end, I hope I've got the flavour in without creating too much acidity.

My biggest problem with this brew so far is by adding some wort to the boil so late I've effectively ended up with a bit too much wort, so the brew is a little under gravity. That's not a terrible problem to have. Apparently it's 1.050. I will recalibrate next time I do this, and add another 10 minutes to the boil time.

So as a follow up, I have a question about the acidification of the wort during the boil: how exactly does this happen? Is it simply due to the fact that the concentration of the low PH dark malts in the brew increases, or does some type of chemical reaction happen to make the PH increase?

If it's just due to the increasing concentration of dark malts in the brew then I may not have avoided all of the dreaded tart tastes - but this will be a learning experience anyway Hopefully the alterations to my mashing process will have made some positive contributions to flavour.

 

[Liam_snorkel]

Have you been tasting the wort prior to fermentation, and is it tart then or only after fermentation?

 

[TimT]

I usually notice the tart tastes after fermentation. I think though it's partly because unfermented sugar covers the taste up. Are you thinking infection?

 

[Liam_snorkel]

I don't know, you'd expect to notice it at least a little bit? Maybe you have a 'house bug' that's contributing the flavour. Maybe it's responding to the slightly lower pH of you darker worts to produce more lactic acid? No idea, just throwing it out there.

check out this link for instance, see how different brett strains respond quite differently to the original pH of wort: http://www.brettanomycesproject.com/dissertation/pure-culture-fermentation/impact-of-initial-concentration-of-lactic-acid/