The sweetness of sugars and artificial sweeteners is measured on the relative sweetness scale where sucrose is the benchmark.Matt in Birdham wrote:I think the fundamental point though, is that you can't make a simple "higher mash temp=sweeter finished beer" assumption. There is no doubt in my mind that *perceived* sweetness depends mostly on the balance of the beer (how bitter it is) and how attenuative the yeast is - and if you want a sweeter beer those are the things to look at first.
On this scale sugars are rated for their sweetness in relation to sucrose with sucrose representing 100%.
Maltose scores about 40-50% whereas maltotriose scores about 30% - therefore you can see maltotriose is significantly less sweet than maltose.
Dextrins are a group of sugars rather than a single sugar - typically they rate at between 10 - 20% on the relative sweetness scale so are that much less sweet again. This is why their presence in beer contributes mouthfeel rather than additional perceived sweetness.
In a typical single infusion mash the ratio produced is about 75% maltose and 25% dextrins but the amylase enzymes which convert the starch into dextrins and dextrins into maltose do not have an "off" switch and if left to their own devices will continue to change the ratio of dextrins:maltose - in theory "mash out" raises the temperature to a point where they are inactivated at the start of the sparge therefore keeping the ratio of sugars where it is intended without taking it high enough to extract excessive amounts of tannins. If the ratio of sugars is changed unfavourably the result can be a thin/dry beer.
Like many of these things there are believers and un-believers.... there are even some who have experimented with cold sparging
If you manipulate the sugar content of your mash towards a higher level of less fermentable sugars then these are mainly what is left behind after the primary fermentation (as the more easily fermented sugars including maltose will have been used first in preference) therefore the beer may have plenty of mouthfeel but relatively little residual sweetness - this can be a difficult idea for people to take in as "sugar" normally = sweet, but as you can see this is not necessarily the case.
The use of a less attenuating yeast will leave comparatively more maltose behind after primary fermentation and because this is sweeter than maltotriose/dextrins will result in a comparatively sweeter beer.
Interestingly some odours can also affect the level of perceived sweetness - and some people are bitterness "supertasters" thanks to their genetics (look up 6-n-propylthiouracil and the TAS2R38 gene if you're interested in that stuff) so there are potentially quite a few variables in the people involved with the taste testing if they haven't been screened... never mind any complexities involved with recipe formulation etc.
