Perfect example of how different the same yeast can act:

Saturday I made ten gallons, with the first five (volume into fermenter) being a Scotch Ale (OG 1.080) and a parti-gyle of almost five gallons (volume into fermenter) of a Scottish 70/- (OG 1.037). They each were from the same mash--so same temperature and grain bill--and batch sparged. They were both aerated proportionally (20 minutes for the Scotch and 15 for the 70/- with an airstone on a fish-tank airpump). They were each pitched with a 1 liter active starter of Scottish Ale Wyeast 1728 (both starters from a larger starter made from the same smack pack). The only major difference besides the gravity is the hops used and amounts.

Both fermenters are in the same tub of water with cold packs and frozen jugs to keep the temp down into the very low 60's. One other difference is the 70/- is in a covered ail pail with blowoff while the Scotch is in a carboy with blowoff. This of course means the 70/- is probably a bit cooler, but the Scotch is probably a bit more steady with fewer temperature fluctuations as the ice packs melt. Keep in mind this is South Texas.

Both went into fermenters within an hour and a half of each other (Scotch first), on Saturday (Dec 15, 2012). Bubbling on the 70/- started within four hours and the Scotch took around six. It is now Monday (start of the third day) and the Scotch still has a large Kraeusen with lots of bubble activity. The 70/- has no bubble activity and (I cracked it open to take a look for this post) the Kraeusen has fallen. However, it is still full of suspended yeasts and turbid. Both are acting very differently, though such similar beers and similar conditions. Lesson learned: Don't judge a fermentation by the airlock.

I'll post final numbers later.

I would expect the scotch ale to take longer as there is more sugar to be consumed, all this seems normal. Also it seems to me that you ARE judging fermentation by the airlock?

COLObrewer said:

all this seems normal

Click to expand...

That was my point.

Actually, I am reporting what is happening with the airlock (reporting is not judging) and what I actually see (observing is not judging) to show (showing is not judging) and to point out (pointing out is not judging) that airlock inactivity does not mean that nothing is going on. It appears you misunderstood the purpose of the post. I did this post because of all the "There are no bubbles, is my beer done?" or "There are no bubbles, is my beer ruined?", or "There are no bubbles, should I stir my beer?", etc. posts that I see. It shows that two almost identical beers with identical yeast, differing only in gravity, are acting very differently--as they should. One can't be sure what is going on just because of what happened with another beer and neither can one know what is going on by what the airlock is doing. This was meant to demonstrate this, not judge the airlock.

I would expect the Scotch Ale to take longer too, because of the high gravity, but if you read it you would see that this was posted at the start of the third day of fermentation. Now that I think about it, with the actual hour that it went in and the hour that this was written, it was the middle of the second day. A new brewer might look at the smaller beer by itself and start to worry something is wrong since there was nothing happening in the airlock. This post was meant to allay some of those fears.

I will assume there was something about my writing that made none of this clear.

I was confused since you were talking about bubbling airlocks "Bubbling on the 70/- started within four hours and the Scotch took around six" since some fermentations happen without any airlock bubbling whatsoever. Bubble activity should not be used to indicate anything that is happening (or not happening) with fermentation, the airlock is simply a means to allow gas to escape without allowing foreign material/organisms to enter.

Sorry, I did misunderstand the purpose of the post.

Sorry if I seemed snippy. I answered back during a bit of a stressful moment from the real world, which is never a good idea.

No worries, most of us are here to learn, I learned something from your post.

Today is day four and the Kraeusen has fallen on the Scotch Ale. I took a sample this morning of each for gravity and tasting, mainly for this thread.

Scotch Ale: OG was 1.080 and now sits at 1.031 (temp adjusted). It is quite dark brown and has pronounced diacetyl aroma, but if any is in the taste it is being masked. This is to be expected with a Wee Heavy. It is warming to the palate, though not uncomfortably. It has very pronounced maltiness, with hop bitterness coming out only in the finish.

Scottish 70/-: OG was 1.037 and sits right now at 1.012. Keep in mind, this is the one in which the Kraeusen fell and airlock stopped in a little under two days. It's color is more of that of old honey. It's nose is clean, but bready. There is no diacetyl noticed in aroma or taste. It is dry and fairly crisp, but not bodiless or cidery--a concern since I had to add about a pound of brewer's sugar to the boil to boost gravity. I calculated around 7 of the gravity points were this addition. The hops bitterness is far more pronounced, but malt is still the primary feature in the taste.

Keep in mind that the 70/- had no noticed airlock activity for the last two days, yet the sample still had suspended yeast visible.

The 70/- will be going into secondary Saturday or Sunday, but the Scotch Ale will stay in primary longer. I'll probably rack it over into secondary after two weeks, depending on gravity. It will be there for at least a month. I know some never secondary but I use it for everything--to free up a larger fermenter, if for no other reason.

And here are a couple pictures of the samples:

Both beers have fermented for a week around 62 deg F. The Scotch is down to 1.028 but I didn't check gravity on the 70/- since last time, because it was already so low--besides cracking open the bucket is not my favorite thing to do, fearing infection at this stage. The fermenters have been moved from the low range and will now sit at a temperature around the low 70's for the rest of their time. In the latest tested sample of the Scotch Ale the diacetyl has definitely reduced.

It seems like you missed the major difference being the Wee Heavy received half the pitching rate compared to the 70/-. The diacetyl is a hint it might have been under pitched. Those little buggers worked it out though and still made beer though.

It is possible. I didn't measure out everything on the starter when I divided them, I just eyeballed them. Diacetyl, though, is common with Scottish Ale yeast, so it could be one or the other.