Does acidulated malt affect fermentation?

[MistuckyCreek]

A customer of my shop brewed a Lemondrop Ale that stalled at 1.029. Temp was perfect, yeast good, hit his OG. He did not check mash ph. Could it be the amount of acidulated malt he used? Here’s the recipe:
6.5# 2 row
2.25# Munich Light
1.25 Flaked Oats
3oz Caramalt
12oz Carapils
2# Acidulated Malt
11oz Lemon Peel
1.25oz Lemongrass
1# Lactose
1 quart lemon balm leaves (fresh)
4 oz Lemondrop Hops
Wyeast 1272
OG 1.060
70 minute mash
70 minute boil
Note- This recipe was previously made successfully with only 1# of acidulated malt

 

[Dgallo]

A customer of my shop brewed a Lemondrop Ale that stalled at 1.029. Temp was perfect, yeast good, hit his OG. He did not check mash ph. Could it be the amount of acidulated malt he used? Here’s the recipe:
6.5# 2 row
2.25# Munich Light
1.25 Flaked Oats
3oz Caramalt
12oz Carapils
2# Acidulated Malt
11oz Lemon Peel
1.25oz Lemongrass
1# Lactose
1 quart lemon balm leaves
4 oz Lemondrop Hops
Wyeast 1272
OG 1.060
70 minute mash
70 minute boil

Mash temp? Could be a combo of mash temp and lactose. 1lb of Lactose will be roughly .008 and if he mashed high say 156 or higher, 1.029 is reasonable

 

[mongoose33]

He used TWO POUNDS of acidulated malt?

A more typical amount might be 4 ounces.

I'm guessing it might have done exactly that, i.e., interfered with the fermentation. Yeast will try to bring the pH of the finished product into a range they tend to like, but that acidulated malt is going to drop the pH in the mash a LOT. I just tossed it into a water calculator to see, and it dropped the resulting mash pH from 5.59 to 4.45, over an entire point.

Did he try to figure out his water profile before brewing this batch?

 

[Silver_Is_Money]

If the "current" wort pH is 3 or less the yeast may be stunted. If it is 3.8 to 4.6 (the typical range for beer) the yeast should not be pH stunted.

 

[Cavpilot2000]

Acidulated malt, used correctly to adjust pH in the proper ranges, is great for fermentations.

Acid malt used improperly (not measured well and/or pH not monitored) could be disastrous by driving pH out of ideal ranges for enzymatic activity or fermentation.

In this case, did he really use 2 pounds of acid malt in a 5 gal batch? Waaaaaaaaaaaaay too much. His pH is probably so low I'm surprised he got any conversion in the mash. Which is probably why the fermentation stalled (lots of unfermentable starches in solution due to incomplete conversion from low pH).

 

[Cavpilot2000]

Yeah, most likely it's not too low for the yeast, but was too low for good conversion in the mash, hence unfermentable starches.

 

[MistuckyCreek]

Mash temp? Could be a combo of mash temp and lactose. 1lb of Lactose will be roughly .008 and if he mashed high say 156 or higher, 1.029 is reasonable

Mash temp was 152. Lactose at flameout

 

[MistuckyCreek]

He used TWO POUNDS of acidulated malt?

A more typical amount might be 4 ounces.

I'm guessing it might have done exactly that, i.e., interfered with the fermentation. Yeast will try to bring the pH of the finished product into a range they tend to like, but that acidulated malt is going to drop the pH in the mash a LOT. I just tossed it into a water calculator to see, and it dropped the resulting mash pH from 5.59 to 4.45, over an entire point.

Did he try to figure out his water profile before brewing this batch?

No, he is new to brewing and is not up to speed with his water profile

 

[Cavpilot2000]

It's not mash temp or the lactose.
It was mash pH.
I'd bet a C-note.

 

[Dgallo]

Mash temp was 152. Lactose at flameout

Yeah so full beta conversion never took place because of the mash ph

 

[couchsending]

“Was made successfully using 1# of acid malt”... I can’t think of a reason to use even that much acid malt for 5 gallons unless the water has a ton of alkalinity. And if so there are way better methods to deal with it than use 1# of acid malt.

 

[MistuckyCreek]

Yeah, most likely it's not too low for the yeast, but was too low for good conversion in the mash, hence unfermentable starches.

He hit his target OG so conversion wasn’t an issue

 

[Cavpilot2000]

No, he is new to brewing and is not up to speed with his water profile

But where did he get the notion to use 2 pounds!?!?
If he wanted to just guess, 4-8 oz would get him in some semblance of a ballpark. 2 pounds is excessive for ANY water profile.

I use acid malt exclusively for pH control (no liquid acid), and I have never added more than 8 oz. And I brew 7 gallon batches.

 

[Cavpilot2000]

He hit his target OG so conversion wasn’t an issue

UNfermentable starches will still dissolve in the wort and contribute to OG.

 

[MistuckyCreek]

Yeah so full beta conversion never took place because of the mash ph

But he hit his target 1.060 OG

 

[Cavpilot2000]

I just ran the numbers through Bru'nWater using my tap water profile and got mash pH of 4.7.
That's wildly outside of healthy ranges for enzymatic activity.

 

[Cavpilot2000]

But he hit his target 1.060 OG

Unfermentable starches will still dissolve in the wort and contribute to OG.
Just like lactose - it dissolves and adds to gravity, but is not a fermentable sugar. Or maltodextrin.

 

[Dgallo]

Unfermentable starches will still dissolve in the wort and contribute to OG.
Just like lactose - it dissolves and adds to gravity, but is not a fermentable sugar. Or maltodextrin.

+1. Exactly

 

[Silver_Is_Money]

People making sour beers have added this much or more acid malt.

 

[Dgallo]

People making sour beers add this much or more acid malt.

Lol who makes a sour by specifically using acidic malt to do so. Seems ludicrous to me. Most people, including myself mash at 5.4 for sours so the sugars are available and use cultures or mixed fermentions to sour the beer.

 

[Vale71]

Very low mash PH inhibits alpha-amylase activity and will cause lower fermentabiliy. Worst case scenario you will have uncoverted starches in the wort which you can only verify with the iodine test. Add to that the lactose and the resulting FG can be quite higher than expected.

 

[Silver_Is_Money]

Lol who makes a sour by specifically using acidic malt to do so. Seems ludicrous to me. Most people, including myself mash at 5.4 for sours so the sugars are available and use cultures or mixed fermentions to sour the beer.

I didn't say they were the brightest bulbs in the box, or that they are traveling down the correct path to a sour. I merely stated that it has been done before.

 

[Miraculix]

I didn't say they were the brightest bulbs in the box, or that they are traveling down the correct path to a sour. I merely stated that it has been done before.

Weyermann actually advertises their acidulated malt with a quick Berliner Weisse recipe, that gets its sourness only from the acidulated malt.

 

[Silver_Is_Money]

Wine musk often starts out at 3.4-3.8 pH and wine yeast don't seem to mind. Same yeast family.

 

[Cavpilot2000]

..

 

[Cavpilot2000]

People making sour beers have added this much or more acid malt.

Weyermann actually advertises their acidulated malt with a quick Berliner Weisse recipe, that gets its sourness only from the acidulated malt.

Wine musk often starts out at 3.4-3.8 pH and wine yeast don't seem to mind. Same yeast family.

You're missing the point - the yeast isn't the issue here, it's mash pH.
You make a sour by adding the culture AFTER the mash - you don't acidify the mash to the point where you inhibit enzymatic activity.
In other words, yes, you can ferment with pH in the 3's, but you can't mash in that range. Apples and oranges.

 

[Dgallo]

Wine musk often starts out at 3.4-3.8 pH and wine yeast don't seem to mind. Same yeast family.

It’s not that the yeast can’t handle the ph. It’s the enzymes in the mash can not properly convert or breakdown down the starches of the mash into smaller chains that the yeast can eat when ph is too low. These starches will be dissolved into the wort, hence why he still hit the target og, but many of them were not converted in the mash so brewers yeast cannot consume them, which is the reason he finished at 1.029

 

[Silver_Is_Money]

You're missing the point - the yeast isn't the issue here, it's mash pH.
You make a sour by adding the culture AFTER the mash - you don't acidify the mash to the point where you inhibit enzymatic activity.
In other words, yes, you can ferment with pH in the 3's, but you can't mash in that range. Apples and oranges.

It’s not that the yeast can’t handle the ph. It’s the enzymes in the mash can not properly convert or breakdown down the starches of the mash into smaller chains that the yeast can eat when ph is too low. These starches will be dissolved into the wort, hence why he still hit the target og, but many of them were not converted in the mash so brews yeast cannot consume them, which is the reason he finished at 1.029

Good point! I can accept this.

 

[chezhed]

I have a customer that insists on making sours by adding acidulated malt in the mash at 20%!!!! I keep trying to tell them that is not the way to make sours but he says he likes the taste.......and complains that his ABV is too low and his fermentation stops.
Oh well....

 

[Cavpilot2000]

I have a customer that insists on making sours by adding acidulated malt in the mash at 20%!!!! I keep trying to tell them that is not the way to make sours but he says he likes the taste.......and complains that his ABV is too low and his fermentation stops.
Oh well....

Some people just don't WANT to learn...