Witbier - stalled or finished fermentation?

[BeardedDragon42]

Hey all,

I'm new to the forums, but I've often found myself here while googling random questions I had about homebrewing.

I currently have my third batch fermenting - a witbier. My first two were kits that I fermented with no temperature control and bottled about a week after the krausen fell with no SG readings ever taken. They turned out great, but this time I thought I'd get a little more scientific.

I'm a huge fan of all things Belgian and thought I'd try my hand at it, but have been met with frustration along the way. I'll try my best to include all the details up front, though it may come out as a wall of text. I slightly modified a recipe that my LHBS had, so here it is:

Grains:
8 oz Pilsner
4 oz Honey Malt

Extracts:
7lb Wheat LME
1/4 oz Bitter Orange Peel (15 min)
1 tsp. crushed coriander (15 min)
1/4 oz Bitter Orange Peel (1 min)
1 tsp. crushed coriander (1 min)

Hops:
1 oz. Sorachi Ace (60min)

Yeast: WLP400

1. Steep grains for 30min @ 155
2. First addition hops
3. Boil etc etc
4. Pitch at 75.

My OG reading was 1.057. According to various style guides, this is a little high for Witbiers. I'm not overly concerned with sticking to rigid guidelines, I just use them to make sure I'm semi on the right track. I did not do a yeast starter, which I quickly learned was a huge mistake with WLP400.

Fermentation started at about 20 hours, with a very slight krausen, maybe 1''. I read online that this yeast needs constant coaxing, so after rousing a few times I got a larger krausen. I was aiming to keep the temperature within the 70-75 range, which I accomplished by putting the carboy in a tub of water and cooling it with frozen water bottles.

I went on vacation during the ferment, so I am not sure when the krausen fell, but I had my roommate maintaining temperature. When I got back the krausen had fallen with a SG of 1.030. This seems waaay too high. What I've been wondering and haven't really been able to find is this - is this to be expected with my recipe? I have read that LME is not as fermentable as one would think, and this Witbier is very low on grains.

My LHBS suggested I pitch US-05 to finish up fermentation. They gave me a dry packet and said I should not rehydrate or do a starter. This seemed wrong to me, but since it IS their recipe, I figured I'd go with it.

Almost two weeks later, I have not seen any signs of fermentation and the SG is still at 1.030. It's been sitting at about 71. Should I proceed to bottling? Or should I try bumping up the temperature? I really don't have any means of doing that other than a warm water bath, but thought I'd ask here before embarking on that journey.

Thank you for your time!

 

[BeardedDragon42]

Update:

I've been doing research all day and came upon this fact: Refractometers are only accurate pre-fermentation due to the fact that alcohol skews the reading. Therefore, you have to use a hydrometer to accurately measure the FG.

Using Northern Brewer's brix/gravity calculator, I have come to this conclusion:

My OG was 1.057, which is 14 brix.

My FG as read by the refractometer is 1.030, the current Brix is 7.6.

Plugging this into the calculator reveals my ACTUAL FG as 1.013, which is right in line with what I was expecting and this means it was time to bottle 1.5 weeks ago.

This seems like a HUGE detail to be aware of before using a refractometer. I was using a friends (the guy who got me into homebrewing) who was not aware of this fact. This probably explains why all of his brews since starting to use it have under attenuated (but not actually, they were just read incorrectly.)

 

[tagz]

Looks like you answered your own question! Enjoy the beer!