How low can you go?

Is it possible to brew a 100% fermentable all-malt, average gravity wort? Not that I want to. But I think there would be something to learn from the discussion.

I want to see the experts input too.  I think it is possible with various strains used.  fg 0.089

For the wort production part, a very low mash temp of ~ 145, mashed for 1.5 - 2 hrs would give you a highly fermentable wort.
Then to close the deal, a saison strain would tear into the sugars pretty vigorously. I’ve gotten down to 1.002 with WY3711 (95% attenuation) and to 1.004 with WY3724 (92% attenuation). Both were average strength worts,ie. ~ 1.055 OG.  I’ve read accounts of 3711 and Belle Dry Saison getting down to around 1.000.
That’s a good example of a highly fermentable wort finished by probably the most attenuative of the beer yeasts.

Add some Brett.

+1 I think that without some very specialized yeast there will always be some longer chain sugars that will not ferment out. By the way are you talking about 100% Apparent Attenuation? ie. a finished gravity of 1.000? I’ve done that with the belle saison but I added some honey.

100% true attenuation would land you below 1. How much below would depend on the worts starting gravity

I guess I should have filed this under “all grain”. More attenuative yeast is the obvious answer especially posted under "yeast and fermentation ". How would one mash to achieve a wort that is 100% fermentable with no long chain sugars?

I’m not sure that it is practically possible. The alpha amylase will leave behind one fermentable bit and one less fermentable bit. The Beta amylase will nibble off the end of the less fermentable bit but still leave a less fermentable bit behind.

The molecules that each enzyme is looking for, once the enzyme has acted on it, will always leave behind an unfermentable bit (This is based on my limited understanding of amylase activity and perhaps others can correct/confirm my thoughts).

There are likely other enzymes one could ADD to the mash to increase fermentability though.

Good stuff! I think that thinking about it in extremes helps gain an understanding of the whole process.
Would you do a step mash? Lowest temperature? Won’t enzymes continue to break down sugars by simply mashing for a longer time? How long til enzymes are denatured?

I would aim for a mash temp of 153 or so. this is in the sweet spot for Alpha activity and on the high end but not too high for beta activity. Mash a LOOOOOOONG time. like overnight or for a day or two. You might get some funk going in the mash (sour mash). try to keep mash temps in the low 150’s high 140’s the whole time. Use some 6 row for added enzymatic power.

I don’t thing the enzymes will denature unless the temp gets too high or the pH gets too low. If the temp drops the activity will go down. But both beta and alpha amylase are dextrin limited. so when there are no more sugar chains of the right shape for them more time will not mean more conversion.

Use alpha amylase powder.

There is a maltase enzyme that is active between 95F and 104F that splits maltose to glucose. If you split up your mash so that you can convert a good chunk of it to maltose, then drop the temp and add more malt to hit the maltase rest, you can end up with a wort that has a very large percentage of glucose and should be super fermentable.

Allegedly, one of the main differences between lager yeast and ale yeast is that lager yeast can metabolize raffinose. Raffinose doesn’t make up a significant amount of the wort sugars, but if you were really trying to eke out every last point of attenuation, then you might want to consider pitching a mix of 3711 along with an attenuative lager strain.