poor fermentation

i made a wit beer on sunday (3 days ago) and pitched some wlp400 at 75F the next morning i checked it and the temp had dropped to 68F so i brought it back up to 75F, now the fermentation is pretty poor i was getting bubbles every 10 seconds for a while but now its down to 40 seconds and its got a weird krausen, to be honest i couldn tell if it was the krausen or leaf hops floating. i gave it a swirl this morning but still not much activity is this normal i know this yeast is slow but should it be more active and is there anything i can do, also i used 1 vile for a 1.5 qallon batch

By 1 vial I'm assuming you mean one of the white labs vials? In that case, you're more than likely done fermenting at that temp. 75 might be a little on the high side (not sure for that strain, but it should be a little more resistant to higher temps), so you'll probably want to let the yeast hang out for another week or two to clean up any off flavors. But I'd guess that you probably overpitched your batch, and at 75 degrees it fermented out overnight one night. You can always take a sample and check, but since you're just talking about a 1.5gal batch, I'd put it off in a corner somewhere for 2 weeks, then come back and take a sample. If its as low as you predict and tastes good, give it another couple days for another sample to make sure its finished and bottle it up.

Take a gravity reading.

The airlock is not a good way to judge fermentation. I have had batches that have had no airlock activity. The only way to make sure that the yeast have done there job is to take a gravity reading.

You are most likely done and you fermented a little high and with one vial for a 1.5 gallon batch you definitely over pitched. Just let it sit for another 2 weeks and then take a gravity sample to see if you are finished.

I never knew you could over pitch, but I used a large fermenting vessel with a fair bit of head space which could account for the poor airlock activity? Ill do a gravity check and see wat it's at thanks

It isn't a poor fermentation, it's your perception of what a ferment should be like. Yeast know what to do and as long as you provide the proper conditions they will do just fine. Temperature changes are not the proper conditions though. Read the literature available about the temperature range that yeast prefers and try to keep it constant near the lower end of that range.

well i just took a gravity reading and to my suprise its down at 1.010, happy days it looks like its done fermenting, but what now should i leave it another week or two? theres still a hell of alot of leaf hops on the top so what should i do next? i tasted the sample and it smells very like white wine and there was a strong bready/lagery flavour to it? i used 60% wheat 30% pilsner and 10% oats can someone explain the lager flavour and smell?

As for what to do next: take the advice if everyone who has posted so far. Just let it be for another 10-14 days. This time will probably help to clean up or mellow some if the strong flavors you tasted. Wheat can definitely leave a breast flavor but this should lessen with time.

Not exactly sure what you mean by lagery

EDIT: rofl

Bready. Bready. Bready. Damn autocorrect

1 vial of that for 1.5 gallons is an overpitch, even if it was at expiration. Those vials are made for 5 gallons. At that temp, it could go fast, but that strain is 66-74. So, it's not too hot.. but.. are you talking about air temp or do you have a strip thermometer on the carboy? If you don't have a strip thermometer get one, they are cheap.

I'm not trying to be pedantic, but you shook the yeast up and left it at room temp for half a day before using it, right?

Honestly, I wouldn't worry about it at all. CO2 is yeast waste and not really a sign of where fermentation is. If you haven't used that yeast before there's no way for you to know how it should do anything, they are all different.

My advice is the same as others. If you are worried, take a reading. But, you need to keep it on the yeast for 2 weeks anyway so why worry? Diacetyl peaks when fermentation is done, let's say on average around day 10 and the only way to be sure it goes away is to leave it on the yeast.

I always do 2 in primary regardless of what I am doing as far as additions or secondaries, whatever.

cervid said:

1 vial of that for 1.5 gallons is an overpitch, even if it was at expiration. Those vials are made for 5 gallons.

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I agree with most everything you said except this. What size batch a vial is intended for is irrelevant. What matters is the yeast pitch count given the gravity and volume of the wort. An expired vial in a 1.5 gallon batch may actually not be enough yeast. You can play around with pitching rate estimates at yeastcalc. It depends on the original gravity and date on the vial (which is used to determine yeast viability).

I usually use mr malty, I'll check out yeast calc. For his beer, for that volume and that yeast it is an overpitch and 1 vial would be fine for 5 gallons, unless he's over 1.060 which I wouldn't think he is.

You're probably right. However, the original poster only provided us with the volume, you still need to know the original gravity and expiration date on the vial to say that definitively. A three day fermentation is fast, but it's a small batch and was fermented hot.

To the OP, it's a good idea to make a starter when using expired yeast. It'ss also good practice to know your pitching rate beforehand and make a starter accordingly.

My effeciency was poor so got an og of 1.044, sadly I can't remember the expiration date I think it was in date tho.

Also I was hoping for a bigger bannana flavour will that come as it mellows out?

Big banana flavor with WLP400? That's not a main characteristic of that yeast strain, http://www.whitelabs.com/yeast/wlp400-belgian-wit-ale-yeast. Perhaps you are confusing a Belgian Wit with a Hefeweizen?

I must of confusing them shoulda been more careful