Malty vs. Sweet

I will be giving a presentation to our local homebrew club at the end of the month and I am asking for your input. I will be discussing the topic of maltiness vs. sweetness in beer. I would also like your opinions on how yeast attenuation, mash temp, hopping rates etc. play into the final perception of malt and sweet in a recipe. In addition I want to touch on some sensory interactions like, how our palate perceives dextrose, maltose, maltotriose etc. I am posting this in the Brew Science section because I would like to teach the new brewers the basics, but also have the science to back up and educate some of the veterans also. Any input is appreciated.

Here's my take on one aspect of it:

Sometimes if your FG is a little high it's because you mashed too high and the wort wasn't as fermentable as intended. Those unfermentable sugars/dextrines are not very sweet so you'll have a lot of body but it won't necessarily be sweet.

Sometimes if your FG is a little high it's because the yeast didn't quite finish the job (it seems yeast health, including aeration, has a big effect on how well the yeast finishes the job). Not really a stuck fermentation per se, just a little higher FG than expected. In this case it is residual fermentable sugars that are leftover and those fermentable sugars are sweet.

In both cases your OG and FG might be exactly the same but the final product tastes different. A Fast Ferment Test (FFT) is a good way to see exactly what the limit of attenuation is and whether you get there. Kaiser has some good articles that touch on this @ Braukaiser.

IME, this seems to be a bigger issue with lagers than ales. That prolonged 'secondary' fermentation (i.e. yeast finishing the job, not talking about bottle-conditioning here) in lagers seems to be more sensitive to yeast health.

I guess I'd say the difference between "sweet" and "malty" is the presence of mellanoidins which are formed by rather complex chemistry involving sugars, amino acids and heat. There are thousands of these and the source materials and treatment of them have a great effect on the nature of the result. If you look at light beers, they are usually neither malty nor sweet i.e. there may be some residual sweetness in them but not much. As you move to slightly darker beers, such as real Pilsner, the maltiness begins to become more noticeable. These beers are often decocted (which generates Maillard products), boiled for 2 hrs or more and often include some portion of caramel malt (which already has appreciable Maillard content). A twist with these beers is sometimes the presence of diacetyl which synnergizes with the sugars and Maillard products to produce (at low levels ) caramel flavors. How do you make caramel (the candy)? Heat sugar with butter (which contains diacetyl).

Moving to still darker beers you get more and more maltiness culminating with bocks and dopple bocks. These are malty for all the same reasons as the Pilsner example but also contain higher kilned (more mellanoidins) malts such as special B, Munich II, Munich I in higher proportion. Strong ales and Barley wines of course have at least roughly similar proportions of higher kilned grains but are not decocted and the esters and high hopping tend to distract the drinker from the maltiness.

This is a great help guys, please keep the feedback coming. I'll check out Braukaiser.

FlyGuy...why did you delete your message?