BrewFather bug

[Aussiekraut]

I know some of you are using BrewFather. so it may concern you too.

I just came across a bug, which, while not huge, can throw out your ABV estimates.

I was playing with a recipe and added some maltodextrin and the ABV estimate changed up by 0.4%, despite maltodextrin clearly being flagged as "not fermentable". Playing around a little more, it seems BF is ignoring the "Not fermentable" property. I looked at BeerSmith and it handles it correctly. 

 

[Pale Man]

31 minutes ago, Aussiekraut said:

I know some of you are using BrewFather. so it may concern you too.

I just came across a bug, which, while not huge, can throw out your ABV estimates.

I was playing with a recipe and added some maltodextrin and the ABV estimate changed up by 0.4%, despite maltodextrin clearly being flagged as "not fermentable". Playing around a little more, it seems BF is ignoring the "Not fermentable" property. I looked at BeerSmith and it handles it correctly. 

 

Ive found bugs in other ways. Sometimes adding small amounts off diferent fermentables, say 100 - 200 grams and the abv doesnt change. Then remove smaller amounts and the abv goes down.

Just on your glitch AK, how much maltodextrin are you adding? I was under the impression it does in fact have small amounts of fermentables.

[Aussiekraut]

1 hour ago, Pale Man said:

Ive found bugs in other ways. Sometimes adding small amounts off diferent fermentables, say 100 - 200 grams and the abv doesnt change. Then remove smaller amounts and the abv goes down.

Just on your glitch AK, how much maltodextrin are you adding? I was under the impression it does in fact have small amounts of fermentables.

Well, I added 500g and ABV shot up by about 0.7%, when I changed it to 250g, it dropped about 0.3%. The same goes for Lactose. The next step was to tick the "not fermentable" on a 2kg ale malt addition and ABV wasn't changed, so it really does ignore the property. BeerSmith on the other hand left the overall ABV unchanged when adding maltodextrin in 250g and 500g amounts. IIRC, maltodextrin ferments a little bit IIRC, I think it is rather negligible and certainly doesn't up ABV by 0.4% per 250g.

[Pale Man]

31 minutes ago, Aussiekraut said:

Well, I added 500g and ABV shot up by about 0.7%, when I changed it to 250g, it dropped about 0.3%. The same goes for Lactose. The next step was to tick the "not fermentable" on a 2kg ale malt addition and ABV wasn't changed, so it really does ignore the property. BeerSmith on the other hand left the overall ABV unchanged when adding maltodextrin in 250g and 500g amounts. IIRC, maltodextrin ferments a little bit IIRC, I think it is rather negligible and certainly doesn't up ABV by 0.4% per 250g.

Ok I see what you mean now. That definately is a glitch, I dont use MD so Ive never come across that.

[Aussiekraut]

12 minutes ago, Pale Man said:

Ok I see what you mean now. That definately is a glitch, I dont use MD so Ive never come across that.

Usually I only use it in things like Porters or Stouts but even then I prefer Lactose. I'm just trying to increase the body of mid-strength or low ABV beers. If you reduce the grain bill, a hot mash will help by creating less fermentable sugars but sometimes you need a little extra. 250g MD should help. 

[Aussiekraut]

I just got word from BrewFather about this. 

The recipe had a fixed FG set, which caused this. It was a copy of a similar beer I had made several times before and it kept all of its settings. The original was imported from BeerSmith, which knows the "estimated FG" and the "measured FG". Measured was different from estimated, so I entered it every time I made the batch. Apparently, when you import from BeerSmith into Brewfather, the latter uses the measured FG as a fixed FG and any calculations around the recipe are done to end up with this SG value. One can argue if this is a bug or a feature but that is beside the point. The point is that it works properly now and I have to go through all of my recipes and clear out the "fixed FG" flag. This also explains why some of my numbers with the BrewZilla are a fair bit off. I moved to BrewFather at the same time I started using the BZ. 

I would have been surprised if such a bug would go unnoticed for long and not be corrected. 

Ok, now I have reliable numbers in the recipe, I can mill another 200g of wheat to add and then get cracking on today's mid-strength fruit sour  

[Shamus O'Sean]

5 hours ago, Aussiekraut said:

I just got word from BrewFather about this. 

The recipe had a fixed FG set, which caused this. It was a copy of a similar beer I had made several times before and it kept all of its settings. The original was imported from BeerSmith, which knows the "estimated FG" and the "measured FG". Measured was different from estimated, so I entered it every time I made the batch. Apparently, when you import from BeerSmith into Brewfather, the latter uses the measured FG as a fixed FG and any calculations around the recipe are done to end up with this SG value. One can argue if this is a bug or a feature but that is beside the point. The point is that it works properly now and I have to go through all of my recipes and clear out the "fixed FG" flag. This also explains why some of my numbers with the BrewZilla are a fair bit off. I moved to BrewFather at the same time I started using the BZ. 

I would have been surprised if such a bug would go unnoticed for long and not be corrected. 

Ok, now I have reliable numbers in the recipe, I can mill another 200g of wheat to add and then get cracking on today's mid-strength fruit sour  

Good to know AK.

I have seen some recipes that you copy from the Brewfather library showing the fixed FG and wondered why.  I thought it (fixed FG) was mostly a useless feature.  However, I have used it on an upcoming low carb recipe where I will be using enzyme to drive the FG close to 1.  Brewfather does not account for the effect of the enzyme on fermentability.  I set the fixed FG to 1.000 for a 4.3% beer.  If I let BF calculate FG, it says 1.008 and an ABV of 3.3%