does higher last runnings gravity increase body?

[madvillain]

Hello!

Im re-brewing big porter soon and wishing to increase overall body/mouthfeel.

The beer is 19P, malt bill is:

Pale Ale 700kg 66%
Flaked Oats 150kg 14%
Chocolate Malt (1000 EBC) 75 kg 7%
Special B 50 kg 5%
Biscuit 37,5 3,5%
Roasted Barley 25 kg 2,5%
Carafa Special II 25 kg 2,5%

BH eff. 76%

Beer fermented out to 5P, it was tasty but seemed a bit thin. Last runnings at previous batch was 3P. Do you think that finishing sparging at higher values could help with that issue? I've heard from other brewers that higher last runnings gravity could result in richer body and mouthfeel in final beer, but just cant really find any confirmation for it. What are your toughts?

Cheers
Mad

[UnFermentable]

Hello!

Im re-brewing big porter soon and wishing to increase overall body/mouthfeel.

The beer is 19P, malt bill is:

Pale Ale 700kg 66%
Flaked Oats 150kg 14%
Chocolate Malt (1000 EBC) 75 kg 7%
Special B 50 kg 5%
Biscuit 37,5 3,5%
Roasted Barley 25 kg 2,5%
Carafa Special II 25 kg 2,5%

BH eff. 76%

Beer fermented out to 5P, it was tasty but seemed a bit thin. Last runnings at previous batch was 3P. Do you think that finishing sparging at higher values could help with that issue? I've heard from other brewers that higher last runnings gravity could result in richer body and mouthfeel in final beer, but just cant really find any confirmation for it. What are your toughts?

Cheers
Mad

I would suggest that by leaving more sugar behind in your last runnings you will just be reducing your BH efficiency and not necessarily getting more body out of it.

You don't mention your mash temp, but I would try raising your mash temp before sacrificing more of your sugar. 3*P should be reasonable for final runnings, IMHO. With 14% oats (and the rest of the bill) I would think you should have plenty of body contributed, but perhaps you are breaking down too much in the mashing process. You can always add some CaraPils/CaraFoam, but I would try higher mash temp first.

You also don't mention your yeast strain, but some strains are capable of breaking down different sugar compounds more completely (maltotriose, tetraose). This can potentially leave less body or "richness" despite a good presence in the wort.

Let us know what you find, I would be curious to hear what works for you.

[madvillain]

I would suggest that by leaving more sugar behind in your last runnings you will just be reducing your BH efficiency and not necessarily getting more body out of it.

You don't mention your mash temp, but I would try raising your mash temp before sacrificing more of your sugar. 3*P should be reasonable for final runnings, IMHO. With 14% oats (and the rest of the bill) I would think you should have plenty of body contributed, but perhaps you are breaking down too much in the mashing process. You can always add some CaraPils/CaraFoam, but I would try higher mash temp first.

You also don't mention your yeast strain, but some strains are capable of breaking down different sugar compounds more completely (maltotriose, tetraose). This can potentially leave less body or "richness" despite a good presence in the wort.

Let us know what you find, I would be curious to hear what works for you.

I'm sorry, thats quite a vital info.

Mash temp was 70C for 90 minutes, then 78 to mash out. Yeast strain was US 05

[ConversationsFC]

does higher last runnings gravity increase body? no!

I might try reducing the mash temp for the first 30 minutes to say 64 - 65 and than bring it up to the 68-70 for the rest. A partial step mash; I have had good success with that sort of stepping, especially when it comes to flaked oaks. BHeff%82-84 when I do that with flaked oats or flaked rye.

Brad

[UnFermentable]

I think a lower mash temp will just leave you less body in general.

The step mash is useful, but usually in beers where you are desiring a dry finish. It has been my experience with many iodine starch conversion tests that full conversion is complete in 40 mins or less with modern highly modified malts. Of course an iodine test on a porter or stout is almost useless as you cant see the unconverted starches.

A 90 min mash rest could be giving your enzymes more time to continue breaking down complex sugars and therefore leaving you less body.

I would suggest trying a shorter mash time (perhaps a regular 60min) to see if it provides more body. 70*C is pretty warm and should provide plenty of body, although you could probably go as high as 72*C. Alpha and Beta peak at specific temperatures but are still present at other temperatures. Extended rest time could possibly cause a lower concentration of enzymes to convert a similar amount of sugars as the peak temperature for those enzymes.

Some will also argue that mash thickness (hydration ratio) can play a large part in this. Usually you will find thicker mashes will convert better (possibly due to a closer interaction of enzymes to malt components), so it is possible a thinner mash could reduce activity and leave you more body.

US-05 should leave a very "normal" amount of complex sugars behind, but you could try S-33 if you want to increase the amount of residual maltotriose.

Again, let us know what you try and the results as I would be interested to hear.