Corn Syrup

[huckdavidson]

Having brewed a test beer with corn syrup and no hops, that corn syrup taste sticks with you and is *very* distinguishable from malt taste.

It is definitely not a favorable taste IMHO and has lessened my liking towards these types of beer.

Beers, that I have taste tested in which I can taste the "corn syrup taste" in:

Busch Light - strong corn syrup, no malt taste
Miller Light - light corn syrup taste, light malt taste - almost balanced but still has a corn syrup finish
Coors Light - light corn syrup but a cooling bitter effect in the after taste

Haven't tried other macros but it's most likely present in all or most beers using corn syrup.

It is strange that up until brewing the test beer I wasn't aware of that taste.

Beers brewed with flaked corn don't seem to have that "corn syrup after taste", they are cleaner in the finish.

The BJCP guidelines don't seem to offer any advice on whether that after taste is an off flavor or not (i.e. is it acceptable or a flaw).

One of the keys then for a homebrewer using corn syrup would be hop and malt balance with the corn syrup to hide the "corn syrup taste".

 

[huckdavidson]

After futzing around with raw corn syrup, I've concluded that:

1.) Straight up raw corn syrup requires enzymes (alpha-amylase or glucoamylase) due to the high amount of unfermentables present 50%+. If this is not done the risk of "corn syrup after taste" is very high.
2.) High fructose corn syrup may not require enzymes as it is much more fermentable than regular corn syrup (only 10% or < unfermentables) - low risk of the "corn syrup after taste"
3.) Brewers crystals, depending on the makeup, are generally in the 20% unfermentable range and may not require enzymes - low risk of "corn syrup after taste"
4.) Mash alpha-amylase enzyme additions tend to leave small amounts of unfermentables depending on mash length and average DP of the mash
5.) Fermenter alpha-amylase enzymes additions tend to ferment dry (1.000 or <)
6.) The more time the alpha-amylase enzymes are allowed to work (i.e. chew) the less hops that are required for balance and the lower the carbohydrate profile.
7.) Glucoamylase general always ferments dry vs. normal alpha amylase.
8.) Various yeasts will break down the higher saccharides but most yeast commonly used in adjunct lagers will not

Commercial beers claiming to use corn syrup vary greatly in their "corn syrup after taste".

Some batches/beers (of the same brand) have very little or none of this after taste and some have a strong corn syrup after taste.

This is surprising (or not?) in commercial examples of corn syrup adjunct beers as it indicates, inferior (cheap) ingredients (using a corn syrup with very high unfermentable %), lack of quality control, lack of measurements and a rushed process. The raw corn syrup wasn't allowed to break down enough before or during fermentation.

Generally speaking a homebrewer (especially one using extract) using raw corn syrup will need to use alpha-amylase enzymes in the mash and/or the fermenter to prevent the corn syrup after taste. They will also want to ensure the IBU is enough to carry the load of unfermentable higher sacharides. Adding corn syrup to an all grain mash was not a problem as the mash enzymes and heat kept the mash fluid and acted quickly to break down the corn syrup. High DP malt does help as the unfermentable load increases greatly with raw corn syrup. On an AIO machine (as opposed to a cooler or BIAB), when adding corn syrup directly to the mash it's wise to only add at higher temperatures when the alpha amylase is active to keep the corn syrup fluid and prevent clumping and gumming up the pump.