Lactose Question

[easymode]

I've read people adding it to the wort pre-fermentation, so I added it to the wort, but I've noticed it messes with the gravity. Is there any reason why this is added early on? It's a non-fermentable sugar.

 

[McKnuckle]

It's added early on (hot side) because it blends much better, being a powder. I wouldn't say it "messes" with the gravity; it is, after all, sugar. You just have to account for the FG being higher due to the lactose component being unfermentable. But that's part of the reason it's used.

 

[mrgrimm101]

Exactly. I recently brewed a milk stout and added 1 lb of lactose during the last 15 minutes or so, just so it has some time in the boil to mix in with the wort. My FG was supposed to be about 1.014 but it ended up being about 1.019. The beer turned out great.

 

[easymode]

So I am guessing it is easier to estimate your gravity by calculating it with the amount of fermentable sugar that's been added when you've been adding lactose?

I wonder if there is an easier way to measure the gravity to account for amount of lactose used. Like, if you are going to add it in the last 15 minutes, then could check the gravity while it's still hot to get a pre-lactose measurement. Then you would measure post lactose so you know what your true gravity is?

Or am I just overthinking this?

 

[mrgrimm101]

Do you have a program, such as Beersmith, that you can plug your recipe into and it will give you this kind of information? That's what I did for my milk stout and it calculated the sugar into the gravity.

I use Beersmith on my PC and on my android phone I use an app called BrewR, which is a pretty good cheap/free (cant remember) recipe app.

 

[zachattack]

So I am guessing it is easier to estimate your gravity by calculating it with the amount of fermentable sugar that's been added when you've been adding lactose?

I wonder if there is an easier way to measure the gravity to account for amount of lactose used. Like, if you are going to add it in the last 15 minutes, then could check the gravity while it's still hot to get a pre-lactose measurement. Then you would measure post lactose so you know what your true gravity is?

Or am I just overthinking this?

You are overthinking it. According to beersmith, lactose has a ppg of 35, so if you know how much you add you can easily account for the gravity just like you would with any other sugar or extract.

 

[easymode]

I didn't know there was such a program. I can go download it. Thanks for that information!

 

[zachattack]

I didn't know there was such a program. I can go download it. Thanks for that information!

The programs help (I love beersmith) but you don't need it for this, it's quite a simple calculation. If lactose adds 35 ppg and you add one pound to a 5.5 gallon batch, it will add 35 ppg * 1 lb / 5.5 gallons = 6.4 points to the gravity.

 

[mrgrimm101]

I didnt know that either

 

[McKnuckle]

If lactose adds 35 ppg and you add one pound to a 5.5 gallon batch, it will add 35 ppg * 1 lb / 5.5 gallons = 6.4 points to the gravity.

Yep. And you can use this equation for mashed fermentables too; you just have to multiply the result times your mash efficiency. Simple sugars don't require that additional element, because they always contribute 100%.

So if you mashed one pound of 2-row (38 ppg) in a 5.5 gallon batch at 70% mash efficiency, you'd have:

38 ppg * 1 lb / 5.5 gallons * 0.70 = 4.8 points

 

[Thanks_Yeasties]

Agreed to using a program to calculate your numbers, there are many different ones out there.

Also, consider adding it post fermentation, since it doesnt ferment it will add residual sweetness and adding it after gives you the chance to taste the beer and adjust the sweetness to your liking.

 

[KeninMN]

I've added it during the boil and I've added it at bottling, mixing it in with the priming sugar and then boiling it. Either way it works.