How Much Lactose To Add To Ginger Beer?

[Barley Belly]

Thinking of putting down another Ginger Beer soon as the 2 previous ones I have made are nearly gone.

The first one I made was a stock Cooper's with 1kg Raw Sugar which came out around 3.2% and tasted OK.

Second was a Morgan's with 1kg Raw Sugar 1kg Dex plus also boiled 250g grated ginger, 2 x crushed cinnamon sticks, 6 x cloves, 1 x lemon (juiced and rind grated) with sugar, strained through muslin then tied up added to wort. It ended up 5%, tasted nice and spicy but ended up a little dry.

My question is how much lactose would I add to 23L to sweeten this up and take some of the dryness away?

 

[Jamz]

Short answer: I don't know.

Longer answer: You could work it out if you wanted.

Lactose is 16% as sweet as sucrose (white sugar). So take say a liter of water and sweeten the water to taste, keeping track of how many grams of sugar you've added to the water. Then just multiply everything out to work out how much lactose you'd need to get the equivalent level of sweetness in a full brew.

For example, say I measure out a liter of water and it takes 10g of sucrose (white sugar) to get it what i think was a good level of sweetness and assume i'm doing a 23L batch.

So 10g of sugar per liter for 23L = 230g of sucrose

Now we already have some sweetness in the kit from the malt. (I'm assuming there's malt in ginger beer?? I've never actually brewed one...)
Say our kit is 1.7kg and 80% of that sugar is going to get fermented out, that leaves 0.2*1700 = 340g of malt. Maltose is 32% as sweet as sucrose, so this makes 340g of malt equivalent to 0.32*340=109g of sucrose. So we subtract this from our 230g and we find that in terms of sweetness, we need to add the equivliant of 230-109=121g of sucrose to the brew.

But obviously we don't want to add sucrose, we want to make up this sweetness with lactose. So given that lactose is 16% as sweet as sucrose, we need to multiply our 121g of sucrose by 6.25 to work out how much lactose to add to give the same amount of sweetness. Doing this gives a figure of 756g of lactose.

If you can find someone to give you an answer that worked for them, obviously thats the way to go. But it should all be pretty simple maths if you can't find an answer and/or you want to work it out yourself.

NB: I've never actually tried this, it just seems like a logical method of arriving at an answer.