Hi Brendan,
There have already been several helpful comments, but I wanted to add a few more.
Glucoamylase (GA or AMG) can be added to the fermentor and it is very effective to reach high levels of fermentability. Typical practice is to add the enzyme at the start of fermentation. On a practical basis, this makes the timing of the addition easier, as you do not have to worry about missing the window for addition, and final attenuation can then be determined by dose rate. In addition, pH is higher at the start of fermentation and that may be more helpful for enzyme activity.
As mentioned in a previous post, the benefit of fermentor addition is the significantly longer time for enzyme contact and activity. This offsets any negative from pH or lower temperatures.
You do need to make sure that the enzyme is inactivated prior to packaging. This is normally done with flash pasteurization, where higher temperatures (and shorter times) can more easily facilitate inactivation. If active enzyme passes through to packaged beer, there is the risk of continued activity, where the beer may become sweeter over time. Or the beer may continue to ferment if there is viable yeast still present in addition to newly created sugar. Plan this carefully.
Reaching 84% fermentability with a mash addition of GA becomes more difficult when the barley crop varies so much, particularly with low starch and high protein of the past few years. Longer rests tend to bring more material into solution, but not all of it is fermentable. On top of this, gelatinization temperatures can increase with drought and heat stress, and in our work, we do see this happening more frequently.
If the gelatinization temperature for starch is above your rest temperature, then there is the possibility that not all starch will be converted to fermentable sugars, so a traditional 149°F/65°C rest, typically listed in references and texts, may no longer be sufficient.
If your mash temperature is lower, at 145°F/ 63°C, then I would definitely focus on starch gelatinization first. It is the critical first step to fermentability. You can increase mash temperatures to gelatinize the starch, but alpha amylase activity may decline due to the higher temperatures. In this case, you would certainly need to add alpha amylase in addition to glucoamylase.
As an aside, Glen Fox has spoken about starch and gelatinization temperatures and he has a podcast available here on the MBAA website as well as a presentation on the ASBC website, if you are interested in tracking them down.
Cheers!
Andrew
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Andrew Fratianni, Dipl. Brew.
Sr. Enzyme Application Specialist
Brewing & Distilling Enzymes
IFF Health & Biosciences
andrew.j.fratianni@iff.com------------------------------
Original Message:
Sent: 12-01-2023 14:37
From: Brendan McGinn
Subject: Looking for recommendations for exogenous amylase enzyme
Good afternoon All!
I am looking for recommendations for extra enzymes that could be added to a mash in addition to Amylo 300 to dry out our light lager tests more completely. A few details on our process, Single infusion targeting 145˚F for 60 min with an addition of the amylo 300 during the mash rest. We don't have any jackets so we're generally unable to heat the mash up to a proper alpha rest and certianly aren't able to perform a mash out, however I am considering figuring out a hot water addition to get the mash up to 150-152 if possible.
We have found that our lighter beers will stop at 1.003-1.004 from ~1.028-1.030 and I'd really like to be able to shave off the last couple of points. We are at the top range of the dosing recommendations for Amylo 300 and I have benchtested our amylo supply and found that a few drops will convert a sample so that it finishes at 1.000.
Does anyone have any experience adding more than the recommended dosage of Amylo 300? Would there be any merit to adding some additional Apha-Amylase at 145˚F or warming up the mash 8-10˚, and could that increase attenuation in the final beer?
Thanks for your help in advance!
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Brendan McGinn
Head Brewer
Zipline Brewing Co.
Lincoln NE
(402) 475-1001
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