Can I increase body after fermentation?

I took an FG on an AG Surly Darkness clone tonight. OG was 1.120 and FG was 1.026. My calculator gives it a 12.34% abv. It seemed to be a bit thin. Can I boil a small amount of water and add 8-16 ounces of lactose to increase the body, or will this also ferment some and increase the ABV?

Yes you can do that. I wouldn’t add any more than 8 oz per 5 gallons.

Thanks Dave,
It’s a 9.5 gallon batch. Will The lactose add sweetness? I plan on aging 5 gallons a couple months and then will bottle. I will keg the rest and let age a month or two. Not sure if I should mess with it yet.

The lactose won’t add much sweetness unless you use a couple pounds of it. I usually wait until bottling or kegging to add it since it won’t ferment anyway. Especially if you are aging the beer a while longer, you can wait because there is a slight possibility that you will need to adjust the amount if your beer mellows or continues to ferment a little more.

Will I need to boil it, or can I add it straight to the fermentor/keg?

Boil it. It does not like to dissolve well at all. It needs to be heated to dissolve and to sanitize.

You could also boil up 3 to 4 oz of maltodextrine and add it. I recently did this to my kegged oatmeal stout that was a little on the thin side.

Worked like a charm.

That does seem a bit low of a FG for a thick Surly Darkness clone. That is one hefty beer! Either options stated above should work. But what I’m really here for is to ask for a recipe if you’re willing??? :mrgreen:

20 lbs Briess Pale Ale Malt
20 lbs golden promise
2 lbs flaked oats
2 lb Candi Syrup D-180
2 lb British Crystal 50-60l
2lb British crystal 70-80l
1 lb special B Malt
1lb chocolate malt
1lb roasted barley
1lb chocolate malt
1lb black patent malt

60 min 4oz Columbus
10min 2 Amarillo
10min 2 oz Simcoe leaf

London Ale 1028 (wyeast)

Thanks for sharing! I am making a RIS for my next batch and I might steal an idea or two from this recipe.