Using Lactose for Sweetening

[Benfleet Brewery]

I’ve only just seen this thread and ironically I made my first ever Milk Stout at the weekend. I followed this recipe which someone else had shared in a previous thread but scaled down the grist to hopefully end up with something closer to 5% abv than 7%!
https://www.homebrewersassociation.org/homebrew-recipe/left-hand-milk-stout-clone/
Since it is only just made I can’t comment on FG. I’ll have to report back.
I added the lactose to the boil 15 minutes before the end using the same method as I use when adding any other sugar and it dissolved really easily. I put it into a large bowl and opened the tap into it during the boil to mix the hot wort with the sugar, added this to the boil then do it one more time to rinse out anything that’s left.

 

[foxy]

I’ve only just seen this thread and ironically I made my first ever Milk Stout at the weekend. I followed this recipe which someone else had shared in a previous thread but scaled down the grist to hopefully end up with something closer to 5% abv than 7%!
https://www.homebrewersassociation.org/homebrew-recipe/left-hand-milk-stout-clone/
Since it is only just made I can’t comment on FG. I’ll have to report back.
I added the lactose to the boil 15 minutes before the end using the same method as I use when adding any other sugar and it dissolved really easily. I put it into a large bowl and opened the tap into it during the boil to mix the hot wort with the sugar, added this to the boil then do it one more time to rinse out anything that’s left.

I noticed that it had no trouble at all dissolving, dissolves better than table sugar due to the finer granules. From what I have read in the short time so far don't be upset if your final gravity is skewed, you will still have the gravity you were aiming for or close to it. The lactose does throw it of and there is a formula to work out how much.

 

[Benfleet Brewery]

I noticed that it had no trouble at all dissolving, dissolves better than table sugar due to the finer granules. From what I have read in the short time so far don't be upset if your final gravity is skewed, you will still have the gravity you were aiming for or close to it. The lactose does throw it of and there is a formula to work out how much.

I use Brewers Friend. Having made the adjustments to try to get an abv of 5% it predicted a OG of 1.054 and that was stop on.

 

[foxy]

I use Brewers Friend. Having made the adjustments to try to get an abv of 5% it predicted a OG of 1.054 and that was stop on.

The OG is the easy part it is the FG that throws a spanner in the works. There is a calculation I saw on Reddit that gives lbs/gallon calculation but I don't understand imperial and at this time of night with a few drinks under my belt can't be bothered to do the conversion.

 

[Hazelwood Brewery]

Lactose and regular table sugar have the same “points per pound per gallon” (US measures) which is 46. This means if you add the same weight of lactose or sucrose you will raise the gravity of your wort by the same amount.

The difference is the fermentability using regular yeast (saccharomyces cerevisiae) - the amount of sucrose converted to alcohol is pretty close to 100% , the amount of lactose converted to alcohol is 0%.

Your wort, produced from mashing grain, will contain a range of sugars. Some of these will be easily digestible by regular yeast, others will be less digestible. Depending on the genetic variation of the yeast you will convert typically between 70% and 90% of these sugars.

If you brew a beer with a regular mash and add sucrose and lactose you can expect to convert around 80% of the wort sugars (in accordance with the yeasts attenuation) plus 100% of the sucrose plus 0% of the lactose.

A wort gravity of 1050, raised to 1060 by adding sucrose and raised again to 1070 by adding lactose might end up (assuming a yeast attenuation of 80%) at 1020 because you’ll have 20% of the sugar from the mash, 0% of the sucrose, and 100% of the lactose unfermented. In reality this might not be exact because environmental factors in the wort and the attenuation of the yeast are not exact or fixed but you won’t be too far adrift.

 

[dad_of_jon]

20/05/2024 - brew 89 - oh FFS.
1.8kg raspberries
2 litres pineapple juice
3kg el dme
500g lactose
11.5 litres treated water
1.075og
2 bottles of boon marriage parfait pitched at 20. clear fage greek yogurt runoff also added
10/06/2024
1.030fg at reading (5.91%) not fully mixed (on the thicker side.) 7.22%abv predicted
16.3l bottled

I used lactobacillus etc with the boon bottle pitch it does take a while to chop through the sugars. My carb tester bottle has gone from squishy to hard. However it's not as rock hard as when I use a standard yeast. I'm keeping them indoors for 2 weeks before going down to the shed. normally 5 days is sufficient.

Tester so far is a thick (not so creamy) fruity sour with acid burn on the back end. Raspberryness is medium. Picture on the brewing thread when I can get pic off phone.

adding a bit of lactobacillus to a milk stout is on my list but I only do sours when its time to replace my plastic so every 2 years ish....

 

[ARNWD]

Lactose and regular table sugar have the same “points per pound per gallon” (US measures) which is 46. This means if you add the same weight of lactose or sucrose you will raise the gravity of your wort by the same amount.

Why not use the metric equivilent instead of US measures that nobody understands or havn't you heard of L°/KG?

 

[Hazelwood Brewery]

Why not use the metric equivilent instead of US measures that nobody understands or havn't you heard of L°/KG?

Because those US measure are so prevalent in articles, in reference tables, and in so many homebrew books.

 

[Benfleet Brewery]

Why not use the metric equivilent instead of US measures that nobody understands or havn't you heard of L°/KG?

333 million Americans understand them!

 

[An Ankoù]

Why not use the metric equivilent instead of US measures that nobody understands or havn't you heard of L°/KG?

I haven't heard of it. It looks like degrees Lovibond divided by??? Kilograms?
But that doesn't make sense so what is it?

Because those US measure are so prevalent in articles, in reference tables, and in so many homebrew books.

US homebrew books should come with a health warning. Those of us who were brought up with imperial weights and measures can convert easily enough, a bit of mental arithmetic, so we're easily led into the trap that their pints and gallons are the same as imperial pints and gallons. Far from it.
My advice would be that if you're not used to convertng this jiggery-pokery then only use recipes that offer metric units, too.

 

[An Ankoù]

While we're talking about lactose, can anyone throw any light on this?
https://www.thehomebrewforum.co.uk/threads/lallemand-belle-saison-yeast.104147/reply?quote=1289642
I think he means beta galactosidase, but I didn't know that brewing yeasts could produce this.

 

[Hazelwood Brewery]

I haven't heard of it. It looks like degrees Lovibond divided by??? Kilograms?
But that doesn't make sense so what is it?

US homebrew books should come with a health warning. Those of us who were brought up with imperial weights and measures can convert easily enough, a bit of mental arithmetic, so we're easily led into the trap that their pints and gallons are the same as imperial pints and gallons. Far from it.
My advice would be that if you're not used to convertng this jiggery-pokery then only use recipes that offer metric units, too.

I did go through a worked example for someone wanting to work out the gravity change for fruit that might be useful for anyone not used to the units (or jiggery-pokery ).

Sure. You need to know the amount of sugar in the fruit as one of your variables. If you still have the pack the fruit came in it will tell you how many grams of sugar there is in 100g of fruit. If you don’t have the pack then the published information on sugar content will be the next best thing, this is 11g.

Assuming 11g /100g of fruit you have 110g of sugar in 1Kg of mango. Expressed as kilos you have 0.11 kilos of sugar.

Simple sugars have an extract potential of 46 gravity points per pound per (US) gallon. We tend to work in Kilos and litres so multiply by 8.35 to get points per kilo per litre: 46 x 8.35 = 384

You don’t have a kilo of sugar in your fruit so adjusting this for the weight you do have (above, bold): 0.11 x 384 = 42

So you would have 42 gravity points if you concentrated all that sugar into 1 litre of wort. If you have more than 1 litre of wort, divide 42 by the number of litres in your FV, say 23: 42 / 23 = 1.8 gravity points.

The additional ABV is 0.13125 x gravity points (all the sugar will be converted to alcohol): 0.13125 x 1.8 = 0.24%

 

[ARNWD]

I haven't heard of it. It looks like degrees Lovibond divided by??? Kilograms?
But that doesn't make sense so what is it?

It's Liter Degrees per Kilogram

One kilogram of stuff raises the gravity of one liter of liquid by the value in L°/KG.

Value in L°/KG multiplied by Weight in KG
__________________________________________  =  Increase in Gravity

             Wort Volume

So for example 500 grams of lactose in 19 liters.

Lactose = 384 L°/KG.

   384 x 0.5
   _________  =  10
      
       19

Fermentable                                      l°/kg   
Barley Syrup                                279   
Brown Sugar                                    367   
Cane Sugar                                    375   
Caramelized Sugar                            319   
Dextrose Monohydrate (Brewing Sugar)        319   
Dried Malt Extract - Dark                    350   
Dried Malt Extract - Extra Pale                350
Dried Malt Extract - Medium                    350
Dried Malt Extract - Pale                    350   
Honey                                        317   
Invert Sugar No 1 Solid                        360   
Invert Sugar No 1 Syrup                        319   
Invert Sugar No 2 Solid                        360   
Invert Sugar No 2 Syrup                        319
Invert Sugar No 3 Solid                        360
Invert Sugar No 3 Syrup                        319
Invert Sugar No 4 Solid                        360
Invert Sugar No 4 Syrup                        319
Lactose                                        384
Lyle's Golden Syrup                            334
Malt Extract Syrup - Amber                    300
Malt Extract Syrup - Dark                    300
Malt Extract Syrup - Medium                    300
Malt Extract Syrup - Pale                    300
Maltodextrin                                300
Maple Syrup                                    259
Molasses                                    300
Munton's - Spraymalt Amber                    320
Munton's - Spraymalt Dark                    315
Munton's - Spraymalt Extra Dark                315
Munton's - Spraymalt Extra Light            320
Munton's - Spraymalt Light                    320
Munton's - Spraymalt Medium                    315
Munton's - Spraymalt Super Dark                310
Treacle                                        300
Wheat Flour                                    304
Wheat Malt Extract                            309

 

[An Ankoù]

It's Liter Degrees per Kilogram

One kilogram of stuff raises the gravity of one liter of liquid by the value in L°/KG.

Thanks @ARNWD . I hadn't seen it expressed that way before.

 

[Hazelwood Brewery]

One kilogram of stuff raises the gravity of one liter of liquid by the value in L°/KG.

This is actually just points per pound per gallon(US) x 8.35 as noted in my worked example.