How do you emphasize the yeast flavor in bread?

Use lots of yeast, and short fermentation times. Prefer cake yeast over the dried types.

Fresh yeast has a specific taste and aroma, which disappears during fermentation, giving you a different, bready taste, which is not the same as yeast taste. Pro bakers are normally trying to achieve perfect fermentation, using low yeast amounts and long fermentation types. Household recipes are trying to take a more convenient route, preferring speedy fermentation (so baking times are reduced) and lots of yeast (because 1. this allows for even quicker rising, and 2. some decades ago, yeast quality was not so good, and you had a chance that the culture in a cake you purchased was barely alive, so it wouldn't rise if you used the minimal amount pro bakers with fresh daily supplies went for). This results in lots of unfermented yeast, which gives homemade breads a specific yeasty taste. While pro bakers will try to avoid it, many people associate the taste with pleasant experience of homemade bread made by a beloved family member, and like having it in their own bread.

So, use cake yeast. About the highest amount you can get away with would be 10% (50 g cake yeast per 500 g flour). But if your bread starts getting a whiff of ammonia, reduce it a bit. Ferment at warm temperatures (30°C is good, yeast starts slowing down over 35) and wait for volume doubling at each stage - should take 30-40 minutes per stage. Be careful to not overproof, because with this ammount of yeast, the dough is fickle, and may not rise if proofed for too long.

There are a couple of methods to increase to yeasty flavor and development in a bread:

• Use a long, slow rise or fermentation, usually refrigerated
• Use a recipe that starts with a preferment or biga, that is fermented once to develop flavor prior to the main fermentation
• Select recipes with fewer additional ingredients or enrichments like eggs, butter, sugar, and so on that would mask the yeasty flavor.

I use the 'old dough' or pate fermentee method, which involves taking a portion of dough - around a fifth works well - from a batch after the first prove, covering it and leaving it in the fridge. Next time you bake bread, take the aged dough and incorporate it into the new dough.

You can keep the cycle going by taking some of this dough and storing it again. Over time this will intensify the flavours in your bread. The old dough will keep fine for 3-4 days in the fridge or a few weeks in the freezer (if freezing then take it out a couple of hours before you need to bake). I've been doing this for the last few months and get a much better taste in my bread.

I'd also recommend using fresh yeast as mentioned above, I find this gives a better flavour than the dried or instant yeasts.

Another pre-ferment approach is what's called a "poolish" in a nod to the polish bakers who supposedly invented the approach. This works great if you bake infrequently, since you only need about 24 hours advance notice and don't need to have remembered to set aside dough from the last time you baked.

I use about a 300:300:1 ratio of water:flour:yeast. So mix 300g each of water and flour together along with about 1g of yeast. Mix it in a large container, since it'll likely double in size. Leave it out, covered, for about 3-4 hours to ferment, then refrigerate it for about 24 hours.

Take it out an hour or so before you plan to use it so it can come to room temperature. You then use it in place of that amount of water and flour in the final recipe.

I picked this approach up from "The Bread Baker's Apprentice" by Peter Reinhardt, which has been a great resource for me.

Try making a sourdough starter, and you can boost it with yeast for a faster rise. I have done this(sans additional yeast), once with a starter I screwed up and did not feed enough- The bread was so yeasty that you could barely eat it!