Clarifying use of enzymes

[Samjproctor]

Hi everyone, this is my first post and I would like to ask for help regarding my second brewing attempt.
It may be too late to save, but….

I am brewing a Belgian blonde which is currently in the fermentation tub sat on a heat pad hooked up to an inkbird temperature regulator.
Fermentation was active for the first four days and then stopped 9points short (OG was 1.057, Target FG was 1.009, I’m measuring 1.018). I left this for a few days to try and get it down with no luck. I gently stirred this and increased the temperature from 20C to 24C. I also tried pitching some more yeast to see if there was anything else left to break down.

None of these methods worked and I read online that chances were the sugars left were of a higher complexity and too strong for the yeast to break down. This is caused by too high mash temperatures, or not cooling the wort quick enough (both seem viable). So I ended up purchasing some brut force amylase to break down what is left, and added a small amount to the fermentation tub.
Now that this has finished my FG is lower than target which was to be expected (sitting at 1.004). However I have two concerns, first is that my beer seems very carbonated at this stage. Should this die down, or do I need to alter the priming sugar? The second is: is there anyway to calculate ABV when amylase is used? Is it the same as normal because the amylase breaks it down and the yeast consumes it, or is it not consumed in this way?

Final remark is that this is my second brew, and both of them have turned out very cloudy. They taste fine but the thick appearance is not the most appealing. Is this an indication of something wrong? Or should I use finings to help this?

I apologise if this seems simple but I have not found clear advice on this. It may be too late to salvage my brew, but it currently still seems to have a good taste (even if it is no longer strictly a Belgian blonde). Any help clarifying this would be appreciated.

 

[Consett26]

ABV in homebrew environments is usually calculated using the formula (OG - FG) * 131.25 but remember to include the decimal point after the 1. There are also several online calculators available.

The cloudiness is less easy to resolve as it depends on what's causing it. Assuming high quality ingredients, and these days I think that's a fair assumption unless you have reason to believe otherwise, then it could be starch, protein, yeast or a combination of all three, or an infection, although I'd rule infection out on account of the beer tasting ok. If its yeast, fining will help but it will clear down on its own if left for long enough.

Protein hazes are caused by a failure to achieve a sufficient hot break (by not boiling vigorously or long enough) or a poor cold break (by not crash cooling). Note that all beers will produce a protein haze if chilled enough unless they've been filtered.

A starch haze is unlikely provided you've mashed for an hour or so but I mention it because my first two or three brews were hazy because of starch. Do you mash out at 75/76 degrees? This is high enough for there still to be some alpha-amylase activity, which breaks starch down in to dextrins but too high for the beta-amylase to convert the dextrins to fermentable sugar. I don't mash out per se, but now hold the wort at 75 degrees while sparging takes place, which achieves the same effect.

I was about to click on post reply when I had another thought - a high proportion of wheat in the mash will produce cloudy beers.

 

[Samjproctor]

Thanks for your reply. So I can still use the standard ABV formula even though I have used amylase to kickstart my stick fermentation?
The ingredients were purchased at a high quality brewers shop as part of an all grain recipe kit (but not a generic prepackaged one. They measure everything out and package themselves). As you said, the infection seems unlikely since the taste is still very good, nothing to indicate slight off flavours at all.

I believe my issue must be to do with the mash stage. If I recall correctly the mash stage said 67C for one hour, but as I am now on a rubbish convection oven after moving house I do believe this may have sat higher at about 74-75C.
The beer looked like a good clear colour after day four of fermentation when it stopped, and it was the later stages that it started to develop haze. I have used finings and it hasn’t achieved too much. I think I may just have to wait until after conditioning as this is now a ‘mish mash’ of solutions tried on this one. It is more trying to learn what I need to change for next time.
Primarily this post was about the first time I have ever used amylase to try and achieve my final gravity after a stuck fermentation failed to get going again. I believe it is because the yeast consumed everything it could but I had a higher concentrate of sugars it could not break down. But I don’t know if there are any negative sides to the amylase that I need to be aware of (other than the final gravity being an unknown as it will break down some stuff you want in there)

 

[Consett26]

Yes, the formula should still work because you've done the same thing that would have happened if everything had worked properly.

Disclaimer: What follows is, I believe, largely correct but is based on my understanding of the process. If anyone wiser than me spots an error please correct it.

Amylase is naturally present in base malts but there are two types of amylase, alpha and beta. Alpha amylase breaks starch down into dextrins (complex sugars) and works best at around 70 degrees. Beta amylase works best at around 60 degrees and breaks dextrins down into simple sugars like glucose and fructose but primarily maltose. Its is these simple sugars that the yeast "eats" (1).

We mash at between 60 and 70 degrees to create a balance of alpha and beta amylase that will produce the style of beer we want. Mashing towards the top end of the range will favour alpha amylase, which will break all the starch down into dextrins but insufficient beta amylase to break all the dextrins down into fermentable sugar. This will produce a sweeter beer with a full-bodied mouth feel. Conversely, mashing at the lower end of the range will favour beta amylase ensuring that every last bit of dextrin is converted to fermentable sugars. This will produce a thinner, drier beer.

By mashing at a very high temperature (2) you'll have had *much* more alpha-amylase activity than beta and will have ended up with an OG comprising a higher than normal level of dextrins because there wasn't enough beta-amylase to break the dextrins down into simple sugars that the yeast can eat. Once the yeast had consumed all the simple sugars, your fermentation stopped.

When you added the amylase you'll have introduced beta amylase, which will have then broken down the dextrins into simple sugars that the yeast will then have consumed, kick-starting the fermentation.


1. Metabolises is probably a better word. It does this in the absence of oxygen dissolved in the wort in order to release an oxygen molecule so it can continue to breathe. Once the sugar molecule has had an oxygen molecule removed its no longer sugar and has become alcohol

2. I doubt that it was as high as 74/75 as this would have resulted in very little, if any beta amylase activity and virtually no fermentation at all. Perhaps you were thinking of the Connells song

 

[Samjproctor]

Thank you so much for taking the time to explain this. There was definitely a lot of initial fermentation activity over the first 4 days, so maybe I need to get a better thermometer too!

I shall keep a closer eye on this initial mash phase next time to try and be more accurate to the recipe. Thanks again